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3800sc random multi cylinder misfire by Madess
Started on: 02-01-2020 04:58 PM
Replies: 38 (544 views)
Last post by: Spoon on 05-28-2020 12:01 AM
Madess
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Report this Post02-01-2020 04:58 PM Click Here to See the Profile for MadessClick Here to Email MadessSend a Private Message to MadessEdit/Delete MessageReply w/QuoteDirect Link to This Post
I have a 3800sc with f23. I have been fighting a misfire for a while. I have swapped the coils, wires and plugs. I have looked for vacuum leaks, and have not found any. I have cleaned the MAF. I have not tested fuel pressure yet. I am checking the fuel pressure next.
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Report this Post02-01-2020 06:27 PM Click Here to See the Profile for OntarioKevSend a Private Message to OntarioKevEdit/Delete MessageReply w/QuoteDirect Link to This Post
When you monitor the misfires live what cylinder(s) are they primarily in?
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Reallybig
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Report this Post02-01-2020 07:10 PM Click Here to See the Profile for ReallybigSend a Private Message to ReallybigEdit/Delete MessageReply w/QuoteDirect Link to This Post
The coils are mounted to a platform that has a plug going into it. The ignition module? I think...
In the stock car it is bolted to the cast iron accessory tensioner bracket. The mating surface on both need to be clean so there is decent conductivity from the module to ground. Corrosion on the aluminum side or both can cause problems. Make sure on yours it is clean with good conductivity. If I'm in that area for maintenance or repairs, I like to clean off any corrosion and apply a light film of dielectric grease to both sides before bolting it back on. Worth a shot
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Report this Post02-01-2020 07:13 PM Click Here to See the Profile for ReallybigSend a Private Message to ReallybigEdit/Delete MessageReply w/QuoteDirect Link to This Post

Reallybig

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I have also had misfires that turn out to be improperly gapped spark plugs or a spark plug where the end was bent during install and shorted to the tip to ground
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Report this Post02-01-2020 09:05 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Madess:

I have a 3800sc with f23. I have been fighting a misfire for a while. I have swapped the coils, wires and plugs. I have looked for vacuum leaks, and have not found any. I have cleaned the MAF. I have not tested fuel pressure yet. I am checking the fuel pressure next.


So I'm not the only one chasing a 3800SC misfire. During my swap I replaced all sensors, ICM, plugs, etc that every body will tell you to do. Figured I would start off all new. The list is extensive. And I endd up with a cylinder #1 misfire code. I even removed the metal shield from the ignition wire boot on #1 figuring it was arcing out. The odd thing is the "ChkEngLigt" only comes on when the tach hits 3K rpm (standing or moving) and you still couldn't tell there was a misfire.

The above was during warm weather. Now its winter and I can actually feel the misfire at 3K rpm. I can also hear an ocassional misfire at idle but not with every firing of the cylinder in question. I connected a vacuum gauge and it holds steady, no load, from 0-3500 rpm with no noticeable needle shaking. Compression check all cylinders were within spec, no highs / no lows.

Bought a new scanner Actron 9680 that shows graphs. Did some recordings but haven't had a chance to decipher the readings yet. May post it on here for the experts. This scanner gives the most likely problem based on the readings and what actual mechanics have done with the same #1 misfire code on same engine.
At the top of the list was "REPLACE #1 EXHAUST VALVE SPRING".

With that info I'm thinking a weak spring could float valve at 3K rpm causing the misfire if it can't maintain contact with the camshaft lobe. Sorry for being long winded.
Madess, get back to me pm or otherwise if you get this figured out and I'll do the same to you should I.

ps: #1 happens to be in one of the most congested areas to work in. ie: cradle drop...

Spoon

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"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

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Madess
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Report this Post02-02-2020 10:47 AM Click Here to See the Profile for MadessClick Here to Email MadessSend a Private Message to MadessEdit/Delete MessageReply w/QuoteDirect Link to This Post
I checked fuel pressure and it is a little below 40psi, I am guessing that is too low. When I rev the motor it does not go up much. I am assuming I need a better fuel pump. I do have a F20000169 sitting on the shelf. I am going to install it, along with some sound deadening, because I hear it has a terrible whine. I will let you know how it goes.
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Dennis LaGrua
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Report this Post02-02-2020 06:26 PM Click Here to See the Profile for Dennis LaGruaClick Here to Email Dennis LaGruaSend a Private Message to Dennis LaGruaEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Madess:

I checked fuel pressure and it is a little below 40psi, I am guessing that is too low. When I rev the motor it does not go up much. I am assuming I need a better fuel pump. I do have a F20000169 sitting on the shelf. I am going to install it, along with some sound deadening, because I hear it has a terrible whine. I will let you know how it goes.


I do not believe that a defective fuel pump would show a random misfire on #1 cylinder as Spoon is reporting. I would lean towards a partially clogged #1 injector or
erratic power to it caused by bad wiring.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
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Report this Post02-02-2020 06:49 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Dennis LaGrua:


I do not believe that a defective fuel pump would show a random misfire on #1 cylinder as Spoon is reporting. I would lean towards a partially clogged #1 injector or
erratic power to it caused by bad wiring.



Mades / Dennis, I did swap #1 injector with #6 opposite bank with no change. Still got chk eng light at 3K rpm. Put injector back where it was and checked wiring with Noids and all wiring checked good. Did test light back probe on injector while running and results were positive. One lead was constant hot and the ECM was flashing away on the other lead. Keep the ideas coming.

Spoon

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"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

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Report this Post02-02-2020 09:41 PM Click Here to See the Profile for OntarioKevSend a Private Message to OntarioKevEdit/Delete MessageReply w/QuoteDirect Link to This Post
When moving coils/injectors to track down a misfire you need to be live monitoring all the cylinder misfires to watch for any changes. Just waiting for codes to pop is not sufficient to track this down.
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Madess
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Report this Post02-03-2020 08:32 AM Click Here to See the Profile for MadessClick Here to Email MadessSend a Private Message to MadessEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Dennis LaGrua:


I do not believe that a defective fuel pump would show a random misfire on #1 cylinder as Spoon is reporting. I would lean towards a partially clogged #1 injector or
erratic power to it caused by bad wiring.



I agree. If it is only cylinder 1, can't remember if you have done one, but I would do a compression check on all the cylinders and see if #1 is a significantly lower than the rest.
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Report this Post02-05-2020 08:57 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Madess, a free bump for you.

Hopefully I'll be posting some scanner readings tomorrow.

Spoon

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"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

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Report this Post02-06-2020 11:42 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Madess, Here is a scan I took today for you and anyone else to check out. Looks like the temp never made it to 180 dg. I better check the stat. And the engine lit up right on schedule 3k.

Record Data

FRAME: 0 TM: 0.0

ABSLT TPS(%) 0.4
CALC LOAD(%) 1.6
COOLANT(°F) 153
ENG SPEED(RPM) 821
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 54
IGN ADV(°) 20.0
LT FTRM1(%) 14.8
MAF(LB/M) 0.62
MAP("HG) 8.0
MIL STATUS Off
O2S11(V) 0.090
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) -0.8
ST FTRM1(%) -0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 1 TM: 1.7

ABSLT TPS(%) 0.0
CALC LOAD(%) 1.6
COOLANT(°F) 153
ENG SPEED(RPM) 840
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 54
IGN ADV(°) 20.0
LT FTRM1(%) 14.8
MAF(LB/M) 0.62
MAP("HG) 8.0
MIL STATUS Off
O2S11(V) 0.605
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) -2.3
ST FTRM1(%) -2.3
VEH SPEED(MPH) 0

------------------------------

FRAME: 2 TM: 3.3

ABSLT TPS(%) 0.0
CALC LOAD(%) 1.6
COOLANT(°F) 153
ENG SPEED(RPM) 838
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 54
IGN ADV(°) 20.5
LT FTRM1(%) 14.8
MAF(LB/M) 0.63
MAP("HG) 7.7
MIL STATUS Off
O2S11(V) 0.715
O2S12(V) 0.445
OBD2 STAT CA
ST FTRM11(%) -0.8
ST FTRM1(%) -0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 3 TM: 5.0

ABSLT TPS(%) 0.8
CALC LOAD(%) 2.0
COOLANT(°F) 153
ENG SPEED(RPM) 943
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 54
IGN ADV(°) 27.0
LT FTRM1(%) 10.2
MAF(LB/M) 1.32
MAP("HG) 8.9
MIL STATUS Off
O2S11(V) 0.035
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) -2.3
ST FTRM1(%) -2.3
VEH SPEED(MPH) 0

------------------------------

FRAME: 4 TM: 6.6

ABSLT TPS(%) 5.1
CALC LOAD(%) 5.5
COOLANT(°F) 153
ENG SPEED(RPM) 2143
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 54
IGN ADV(°) 30.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.05
MAP("HG) 7.4
MIL STATUS Off
O2S11(V) 0.290
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 0.8
ST FTRM1(%) 0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 5 TM: 8.2

ABSLT TPS(%) 6.3
CALC LOAD(%) 6.7
COOLANT(°F) 153
ENG SPEED(RPM) 2585
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.0
LT FTRM1(%) -1.6
MAF(LB/M) 2.39
MAP("HG) 6.8
MIL STATUS Off
O2S11(V) 0.640
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 0.8
ST FTRM1(%) 0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 6 TM: 9.9

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.5
COOLANT(°F) 154
ENG SPEED(RPM) 2830
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.54
MAP("HG) 6.5
MIL STATUS Off
O2S11(V) 0.570
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 0.8
ST FTRM1(%) 0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 7 TM: 11.6

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.5
COOLANT(°F) 154
ENG SPEED(RPM) 2899
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.0
LT FTRM1(%) -1.6
MAF(LB/M) 2.51
MAP("HG) 6.5
MIL STATUS Off
O2S11(V) 0.835
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 0.8
ST FTRM1(%) 0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 8 TM: 13.2

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.5
COOLANT(°F) 154
ENG SPEED(RPM) 2911
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.63
MAP("HG) 6.5
MIL STATUS Off
O2S11(V) 0.820
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 0.8
ST FTRM1(%) 0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 9 TM: 14.9

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.5
COOLANT(°F) 154
ENG SPEED(RPM) 2957
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.55
MAP("HG) 6.5
MIL STATUS Off
O2S11(V) 0.495
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 0.8
ST FTRM1(%) 0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 10 TM: 16.5

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.5
COOLANT(°F) 154
ENG SPEED(RPM) 2984
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.0
LT FTRM1(%) -1.6
MAF(LB/M) 2.56
MAP("HG) 6.5
MIL STATUS Off
O2S11(V) 0.450
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 0.8
ST FTRM1(%) 0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 11 TM: 18.1

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.5
COOLANT(°F) 154
ENG SPEED(RPM) 2964
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.60
MAP("HG) 6.5
MIL STATUS Off
O2S11(V) 0.260
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) -2.3
ST FTRM1(%) -2.3
VEH SPEED(MPH) 0

------------------------------

FRAME: 12 TM: 19.8

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.8
COOLANT(°F) 156
ENG SPEED(RPM) 3039
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.57
MAP("HG) 6.5
MIL STATUS Off
O2S11(V) 0.845
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) -2.3
ST FTRM1(%) -2.3
VEH SPEED(MPH) 0

------------------------------

FRAME: 13 TM: 21.4

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.8
COOLANT(°F) 156
ENG SPEED(RPM) 3046
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.57
MAP("HG) 6.5
MIL STATUS Off
O2S11(V) 0.125
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) -2.3
ST FTRM1(%) -2.3
VEH SPEED(MPH) 0

------------------------------

FRAME: 14 TM: 23.1

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.5
COOLANT(°F) 156
ENG SPEED(RPM) 3053
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.59
MAP("HG) 6.5
MIL STATUS Off
O2S11(V) 0.250
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) -2.3
ST FTRM1(%) -2.3
VEH SPEED(MPH) 0

------------------------------

FRAME: 15 TM: 24.7

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.5
COOLANT(°F) 156
ENG SPEED(RPM) 3060
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.64
MAP("HG) 6.5
MIL STATUS Off
O2S11(V) 0.810
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) -2.3
ST FTRM1(%) -2.3
VEH SPEED(MPH) 0

------------------------------

FRAME: 16 TM: 26.4

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.8
COOLANT(°F) 158
ENG SPEED(RPM) 3053
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.63
MAP("HG) 6.5
MIL STATUS Off
O2S11(V) 0.165
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) -2.3
ST FTRM1(%) 0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 17 TM: 28.0

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.5
COOLANT(°F) 158
ENG SPEED(RPM) 3082
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.65
MAP("HG) 6.5
MIL STATUS Off
O2S11(V) 0.820
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 0.8
ST FTRM1(%) 0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 18 TM: 29.7

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.8
COOLANT(°F) 158
ENG SPEED(RPM) 3082
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.63
MAP("HG) 6.5
MIL STATUS Off
O2S11(V) 0.095
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 0.8
ST FTRM1(%) 0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 19 TM: 31.4

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.8
COOLANT(°F) 160
ENG SPEED(RPM) 3104
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.60
MAP("HG) 6.5
MIL STATUS Off
O2S11(V) 0.855
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 0.8
ST FTRM1(%) 0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 20 TM: 33.0

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.5
COOLANT(°F) 160
ENG SPEED(RPM) 3104
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.65
MAP("HG) 6.5
MIL STATUS Off
O2S11(V) 0.720
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 0.8
ST FTRM1(%) 0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 21 TM: 34.7

ABSLT TPS(%) 7.5
CALC LOAD(%) 7.8
COOLANT(°F) 160
ENG SPEED(RPM) 3082
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.59
MAP("HG) 6.5
MIL STATUS Off
O2S11(V) 0.135
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 0.8
ST FTRM1(%) 0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 22 TM: 36.4

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.5
COOLANT(°F) 162
ENG SPEED(RPM) 3096
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.54
MAP("HG) 6.5
MIL STATUS On
O2S11(V) 0.850
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 0.8
ST FTRM1(%) 0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 23 TM: 38.0

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.5
COOLANT(°F) 162
ENG SPEED(RPM) 3018
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.51
MAP("HG) 6.5
MIL STATUS On
O2S11(V) 0.675
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 0.8
ST FTRM1(%) 0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 24 TM: 39.7

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.5
COOLANT(°F) 162
ENG SPEED(RPM) 3011
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -1.6
MAF(LB/M) 2.46
MAP("HG) 6.5
MIL STATUS On
O2S11(V) 0.120
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 0.8
ST FTRM1(%) 0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 25 TM: 41.3

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.5
COOLANT(°F) 162
ENG SPEED(RPM) 2998
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) -0.8
MAF(LB/M) 2.50
MAP("HG) 6.5
MIL STATUS On
O2S11(V) 0.130
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 4.7
ST FTRM1(%) 4.7
VEH SPEED(MPH) 0

------------------------------

FRAME: 26 TM: 43.0

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.5
COOLANT(°F) 163
ENG SPEED(RPM) 3032
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.5
LT FTRM1(%) 0.0
MAF(LB/M) 2.54
MAP("HG) 6.5
MIL STATUS On
O2S11(V) 0.270
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 0.8
ST FTRM1(%) 0.8
VEH SPEED(MPH) 0

------------------------------

FRAME: 27 TM: 44.7

ABSLT TPS(%) 6.7
CALC LOAD(%) 7.1
COOLANT(°F) 163
ENG SPEED(RPM) 3011
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 32.0
LT FTRM1(%) 0.8
MAF(LB/M) 2.50
MAP("HG) 6.5
MIL STATUS On
O2S11(V) 0.270
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 4.7
ST FTRM1(%) 4.7
VEH SPEED(MPH) 0

------------------------------

FRAME: 28 TM: 46.3

ABSLT TPS(%) 6.3
CALC LOAD(%) 5.9
COOLANT(°F) 163
ENG SPEED(RPM) 2730
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 22.0
LT FTRM1(%) 6.3
MAF(LB/M) 0.89
MAP("HG) 5.0
MIL STATUS On
O2S11(V) 0.030
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 10.9
ST FTRM1(%) 10.9
VEH SPEED(MPH) 0

------------------------------

FRAME: 29 TM: 48.0

ABSLT TPS(%) 0.4
CALC LOAD(%) 2.0
COOLANT(°F) 165
ENG SPEED(RPM) 1167
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 20.5
LT FTRM1(%) 10.2
MAF(LB/M) 0.67
MAP("HG) 6.8
MIL STATUS On
O2S11(V) 0.885
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 4.7
ST FTRM1(%) 4.7
VEH SPEED(MPH) 0

------------------------------

FRAME: 30 TM: 49.6

ABSLT TPS(%) 0.0
CALC LOAD(%) 1.6
COOLANT(°F) 165
ENG SPEED(RPM) 869
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 52
IGN ADV(°) 20.0
LT FTRM1(%) 15.6
MAF(LB/M) 0.57
MAP("HG) 7.7
MIL STATUS On
O2S11(V) 0.845
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 1.6
ST FTRM1(%) 1.6
VEH SPEED(MPH) 0

------------------------------

FRAME: 31 TM: 51.3

ABSLT TPS(%) 0.0
CALC LOAD(%) 1.6
COOLANT(°F) 165
ENG SPEED(RPM) 778
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 54
IGN ADV(°) 20.5
LT FTRM1(%) 15.6
MAF(LB/M) 0.61
MAP("HG) 8.3
MIL STATUS On
O2S11(V) 0.055
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 1.6
ST FTRM1(%) 1.6
VEH SPEED(MPH) 0

------------------------------

FRAME: 32 TM: 52.9

ABSLT TPS(%) 0.0
CALC LOAD(%) 1.6
COOLANT(°F) 167
ENG SPEED(RPM) 882
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 54
IGN ADV(°) 20.0
LT FTRM1(%) 16.4
MAF(LB/M) 0.59
MAP("HG) 7.7
MIL STATUS On
O2S11(V) 0.060
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 2.3
ST FTRM1(%) 2.3
VEH SPEED(MPH) 0

------------------------------

FRAME: 33 TM: 54.6

ABSLT TPS(%) 0.0
CALC LOAD(%) 1.6
COOLANT(°F) 167
ENG SPEED(RPM) 858
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 54
IGN ADV(°) 20.0
LT FTRM1(%) 16.4
MAF(LB/M) 0.59
MAP("HG) 7.7
MIL STATUS On
O2S11(V) 0.195
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 6.3
ST FTRM1(%) 6.3
VEH SPEED(MPH) 0

------------------------------

FRAME: 34 TM: 56.2

ABSLT TPS(%) 0.0
CALC LOAD(%) 1.6
COOLANT(°F) 167
ENG SPEED(RPM) 830
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 54
IGN ADV(°) 20.0
LT FTRM1(%) 16.4
MAF(LB/M) 0.58
MAP("HG) 7.7
MIL STATUS On
O2S11(V) 0.635
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 6.3
ST FTRM1(%) 6.3
VEH SPEED(MPH) 0

------------------------------

FRAME: 35 TM: 57.9

ABSLT TPS(%) 0.0
CALC LOAD(%) 1.6
COOLANT(°F) 167
ENG SPEED(RPM) 825
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
IAT(°F) 54
IGN ADV(°) 20.0
LT FTRM1(%) 16.4
MAF(LB/M) 0.57
MAP("HG) 7.7
MIL STATUS On
O2S11(V) 0.715
O2S12(V) 0.450
OBD2 STAT CA
ST FTRM11(%) 6.3
ST FTRM1(%) 6.3
VEH SPEED(MPH) 0

Comments welcome..

Spoon


------------------
"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

[This message has been edited by Spoon (edited 02-06-2020).]

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OntarioKev
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Report this Post02-07-2020 10:48 AM Click Here to See the Profile for OntarioKevSend a Private Message to OntarioKevEdit/Delete MessageReply w/QuoteDirect Link to This Post
Are those the only parameters you can log? It doesn't appear to contain any of the misfire counts for the cylinders. I do see LT fuel trims sitting at 16% in some areas which isn't ideal (not the end of the world though).

Please let us know if you are able to log other parameters.
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Report this Post02-07-2020 02:36 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by OntarioKev:

Are those the only parameters you can log? It doesn't appear to contain any of the misfire counts for the cylinders. I do see LT fuel trims sitting at 16% in some areas which isn't ideal (not the end of the world though).

Please let us know if you are able to log other parameters.


I'm still learning this scanner Actron 9680. I just upgraded the scanner software and it displays a lot of good info. In my opinion their software for the PC program sucks. It lags behind the scanner upgrade instructions. When the scanner shows "PRINT ALL" and I press the scanner button I would expect to see all the data printed out.

Just to use the PRINT OPTION the PC program instructions mention USB & Serial connector (scanner only has USB connector & cable) and what to look for and where to look in "Device Manager" for the com port # if it doesn't show up on the scanner yada, yada. It's like going back to Windows 95. I've tried to run this program on 3 different PC's --Win 7, 8.1 & 10 all professional level. It was only chance that the print out in above posting occurred. Sorry for the rant. I'll see if I can get a more complete print out even if I have to transpose data from the scanner using something called paper & pencil.

Spoon


------------------
"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

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Report this Post02-07-2020 05:58 PM Click Here to See the Profile for PhilClick Here to Email PhilSend a Private Message to PhilEdit/Delete MessageReply w/QuoteDirect Link to This Post
I chased a misfire in my 3800sc for 3 years - finally found it. Turns out three of the bolts on the super charger would loosen up and develop a slight vacuum leak. Leak wouldn't show up using a spray test
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Report this Post02-07-2020 09:55 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Bet you were a happy camper that day! Plus an inexpensive fix not counting any unneeded parts you threw at it over the years.

Spoon

------------------
"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

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Report this Post02-10-2020 09:42 PM Click Here to See the Profile for Dennis LaGruaClick Here to Email Dennis LaGruaSend a Private Message to Dennis LaGruaEdit/Delete MessageReply w/QuoteDirect Link to This Post
Your PCM is trying to increase fuel as the LTFT and STFT are both going positive. Anything over 5% is typically a concern.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

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Report this Post02-12-2020 10:54 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Dennis LaGrua:

Your PCM is trying to increase fuel as the LTFT and STFT are both going positive. Anything over 5% is typically a concern.



Dennis, I agree with your prognosis. Just have to figure out whats causing the lean condition at 3k rpm. My scanner does show voltage wave forms but it doesn't seem to print them out. I'll try doing a video of the scanner screen using my cell phone.

Spoon

------------------
"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

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Report this Post02-16-2020 03:51 PM Click Here to See the Profile for MadessClick Here to Email MadessSend a Private Message to MadessEdit/Delete MessageReply w/QuoteDirect Link to This Post
Ok, so I put in the Walbro fuel pump. I turned the car to on, and it was still a little over 40psi. So as I test, I connected it directly to 12v and it showed 55psi at the fuel rail. I then started the car, and the pressure dropped back to 40psi. I am assuming the has something to do the fuel pressure regulator. When I hit the gas the fuel pressure really doesn't change.

This is what the fuel connections look like.
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Report this Post02-16-2020 10:17 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Madess, your description & pic look proper. A few days ago I was trying to do more scans for my misfire and ran out of gas. I'll try again after I fuel up.

Spoon


------------------
"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

[This message has been edited by Spoon (edited 02-16-2020).]

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Report this Post02-20-2020 09:11 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Madess,
Okay I found some of my problem. The fuel CANISTOR PURGE SOLENOID was stuck open. I could blow air thru it in both directions, energized or de-energized. So the Mass Air Flow sensor saw this unaccounted for air as a leak causing a lean condition.

I purchased a new AcDelco replacement and installed it. Started the engine and it idled horrible. I'll need to do some road trips to get the ECM to adjust. Then I'll take some more scans. I also purchased some Autolite XP-606 spark plugs to replace the recommended AcDelco 41-101.

More to come.... I'll keep you posted.

Spoon

------------------
"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

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Report this Post02-29-2020 04:59 AM Click Here to See the Profile for Dennis LaGruaClick Here to Email Dennis LaGruaSend a Private Message to Dennis LaGruaEdit/Delete MessageReply w/QuoteDirect Link to This Post
Charlie: I just recall that after I did my my 3800SC swap and drove to Carlisle, I was getting the random misfire code. It turned out to be a dirty MAF sensor. I purchased a can of special CRC MAF cleaner, sprayed the unit and the problem went away. The MAF input gives you the main fueling signal. If the unit is dirty or defective it will put out erroneous reading and give a random misfire. In my case I believe what happened was my choice of air filter. It was a K&N unit that uses the oil sprayed resin element. The unit was new and perhaps had too much oil on it. A tiny bit of oil got on the MAF wire and threw off the readings.
You may not have a K&N filer but your 3800SC was a used engine.Just a bit of dirt on the MAF wires and there's your random misfire code..

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

[This message has been edited by Dennis LaGrua (edited 02-29-2020).]

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Report this Post02-29-2020 04:43 PM Click Here to See the Profile for cmechmannClick Here to Email cmechmannSend a Private Message to cmechmannEdit/Delete MessageReply w/QuoteDirect Link to This Post
Don't know if anyone has suggested this yet.
Waste spark ignition (coil ignites 2 cylinders) are very picky of what plugs you use.
Don't use any type of platinum plugs. Even dual platinum. Either iridium or cheap copper core. I've had many occasions of platinum causing phantom, random misfires. The copper will work, but will wear quickly in boosted engines.
Also stick with A/C Delco or NGK on GM coils.
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Report this Post03-22-2020 04:18 PM Click Here to See the Profile for MadessClick Here to Email MadessSend a Private Message to MadessEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Spoon:

Madess,
Okay I found some of my problem. The fuel CANISTOR PURGE SOLENOID was stuck open. I could blow air thru it in both directions, energized or de-energized. So the Mass Air Flow sensor saw this unaccounted for air as a leak causing a lean condition.

I purchased a new AcDelco replacement and installed it. Started the engine and it idled horrible. I'll need to do some road trips to get the ECM to adjust. Then I'll take some more scans. I also purchased some Autolite XP-606 spark plugs to replace the recommended AcDelco 41-101.

More to come.... I'll keep you posted.

Spoon




Glad to hear Spoon. I got the wiring finished for the reroute of the fuel pump circuit today. I have to clean everything up, and get it put back together. I should be be able to test drive it next weekend, so I will let you know how it goes.
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Report this Post03-29-2020 04:03 PM Click Here to See the Profile for MadessClick Here to Email MadessSend a Private Message to MadessEdit/Delete MessageReply w/QuoteDirect Link to This Post
SIGH - still have the random misfire, but it didn't blink so I don't know how much it is misfiring, and it took a while to do it. The biggest issue is, it seems like when the super charger tries to engage, it kills the power of the car, like there is something wrong with the super charger.

Not sure how to pull logs from the computer, I have a Bluedirver ODBII scan tool.

Any thoughts or suggestions would be appreciated.
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Report this Post03-29-2020 07:45 PM Click Here to See the Profile for MadessClick Here to Email MadessSend a Private Message to MadessEdit/Delete MessageReply w/QuoteDirect Link to This Post
Well, tried something real quick - I removed the hose the fuel pressure regulator and it the fuel pressure is 55 psi, and all the time even when I hit the gas, so bad fuel pressure regulator?
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Report this Post04-04-2020 08:38 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Madess:

Well, tried something real quick - I removed the hose the fuel pressure regulator and it the fuel pressure is 55 psi, and all the time even when I hit the gas, so bad fuel pressure regulator?


I believe that's the way its suppose to work. With no vac on the regulator your getting maximum pressure 55 psi in your case. Hitting the gas will have minimal effect with vac hose off. With it connected the pressure will modulate as you put more load on the engine.

Spoon
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Report this Post04-04-2020 08:52 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
A few weeks ago I replaced my bad CANISTOR PURGE SOLENOID and the engine ran horribly. After a few miles of driving the idle went back to normal. I then replace all the spark plugs with Autolite XP-606 and gaped them at .055.
I drove it 5 or 6 miles and so far no chk eng light. Fingers crossed. I'll put the scanner on it and get some readings soon.

Spoon

------------------
"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

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Report this Post04-04-2020 09:33 PM Click Here to See the Profile for MadessClick Here to Email MadessSend a Private Message to MadessEdit/Delete MessageReply w/QuoteDirect Link to This Post
No purge solenoid that I can find.

Spark plugs are uridium - pre gapped.

Why is the fuel pressure low with the regulator connected? Shouldn't it still be over 50, and when I hit the gas with the regulator connected the pressure should be up or stay the same, not drop, which is what makes me think I have a bad regulator.

I am also wondering if maybe there is one or more bad fuel injectors.

I am getting a code reader and should be able to test logs soon.
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Report this Post04-05-2020 03:14 PM Click Here to See the Profile for OntarioKevSend a Private Message to OntarioKevEdit/Delete MessageReply w/QuoteDirect Link to This Post
You want lower pressure under low load (vacuum), and higher pressure under load. It will also raise 1:1 with boost so at 10psi of bost your pressure would be 65psi, so the same amount of fuel is flowing.

Its operating exactly as expected. When you pull the vacuum line you get atmospheric pressure, and your expected fuel pressure.
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Report this Post04-06-2020 05:17 AM Click Here to See the Profile for MadessClick Here to Email MadessSend a Private Message to MadessEdit/Delete MessageReply w/QuoteDirect Link to This Post
Well, fuel pressure regulator aside, the car is running terrible at idle. I removed spark plugs one at a time. It didn't run very different with some removed, others it died. I believe it is only running on a few cylinders. My guess is bad or clogged fuel injectors, I have had cars with this issue before.
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Report this Post04-06-2020 09:56 AM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Madess:

Well, fuel pressure regulator aside, the car is running terrible at idle. I removed spark plugs one at a time. It didn't run very different with some removed, others it died. I believe it is only running on a few cylinders. My guess is bad or clogged fuel injectors, I have had cars with this issue before.


To prove your suspicion, shoot a little starting fluid into it as it idles. It should smooth out for a moment.
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Report this Post04-07-2020 03:59 PM Click Here to See the Profile for MadessClick Here to Email MadessSend a Private Message to MadessEdit/Delete MessageReply w/QuoteDirect Link to This Post
Starter fluid makes it not want to start, and while it is running makes it die? Doesn't that mean it is running running rich. I am going to remove the ignition module and have it tested, just to eliminate that.

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Report this Post04-08-2020 08:02 AM Click Here to See the Profile for MadessClick Here to Email MadessSend a Private Message to MadessEdit/Delete MessageReply w/QuoteDirect Link to This Post
Found the possible issue. The high and low rpm failed on the ignition module.
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Report this Post04-09-2020 12:25 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Madess:

Found the possible issue. The high and low rpm failed on the ignition module.


Madess, I came across this posting that may be of help on the misfire. I knew that there were 2 AC-Delco coils that will work on the 3800na but only one of them is for the 3800sc. The D576 has more output. Check it out.

https://www.facebook.com/GM...bsi/476526612496506/

In case the link stops working in the future here's the copied version as well. I think this is important.

*************************************

GM 3800 Service Tips, Techniques, and Advice
May 3, 2015 ·

Which Coil Packs to use?

I found a nice post on The Pontiac Bonneville Club website describing and rating the various options for coil packs. Basically, you can't go wrong with AC-Delco D576's for both supercharged (SC) and naturally-aspirated NA engines. You can get D576s from Amazon for around $45 a piece (and free shipping if you can wait a week). I will abridge the post here (in case the post is deleted later) and post the link in the comment section to give due credit.
The service life of an OEM AC Delco coil pack is around 140K miles, longer in cold climates. They tend to fail when hot, each failed coil pack causing misfires on its two paired cylinders (1 and 4, 2 and 5, 3 and 6) A set of OEM coil packs will tend to fail within a window of 1K-5K miles of each other. So if one goes, plan on replacing the other two. As one strategy, you can buy one coil pack now to use in an emergency. They are easy to install on the road (two bolts) with simple tools you can assemble ahead of time. You can use Torque Pro to identify the bad coil by looking at the cylinder misfire counts. (See the previous post on this page on how to use Torque pro to identify misfires.) Running the engine with prolonged misfires runs the risk of destroying the catalytic converter.

ACDelco D576 - most expensive; direct OE replacements for SSEi (SC engine). These coils have blue tabs on the bottom side. Can be used in SLE and SE as a "mod" upgrade as long as all three coils are the same.

MSD 8224 - These are comparable to D576 and are suitable for SSEi (SC engine). Considered by some to be a "mod" due to their red color and association with racing. Some feel that they are slightly better than D576 and others say they are slightly less good. Either way, most seem to agree that they are pretty close to D576. Prices are similar to D576. As with D576, can be used in SLE and SE (NA engine) as a "mod" upgrade.
ACDelco D555 - Direct OE replacements for SLE and SE (NA engine). Puts out slightly less spark than D576 (voltage and amperage are different). Less expensive than D576. These coils do not have any blue on the bottom. Not recommended for SSEi (SC engines); will work but decreases performance and may cause longer-term issues, especially if blue and non-blue are mixed on same car.

ACDelco E530C - a "one size fits all" replacement; suitable for L36 engines in any car. Appears to be pretty much the same as D555, but some feel that it is slightly inferior. Less expensive than D576.As with D555, is not recommended for SSEi (SC engine).

Delphi GN10123 - Same as E530C. Possibly made in same factory. Just a different brand name on the box. As with E530C and D555, is not recommended for SSEi. Delphi used to be a part of General Motors, and still makes many parts for AC Delco.

Airtex/Wells C849 - aftermarket equivalent of E530C (sold under "Duralast" brand at AutoZone). Felt by many to be of lesser quality than Delphi/ACDelco. (around $22-$27) Not recommended, unless you do not plan on keeping the car for long.

Standard Motor Products DR39T - very low-priced. Commonly found on eBay, also on Rock Auto as "Economy option." (around $15-$20) Not recommended, unless you do not plan on keeping the car for long.

Spoon

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"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

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Madess
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Report this Post04-16-2020 10:31 PM Click Here to See the Profile for MadessClick Here to Email MadessSend a Private Message to MadessEdit/Delete MessageReply w/QuoteDirect Link to This Post
The car runs much better with the new module, but it still bogs down when under boost.

Question - does the vacuum line for the fuel pressure regulator connect pre or post boost?
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ignorant prodigy
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Report this Post04-17-2020 03:05 PM Click Here to See the Profile for ignorant prodigyClick Here to Email ignorant prodigySend a Private Message to ignorant prodigyEdit/Delete MessageReply w/QuoteDirect Link to This Post
The T runs to the bottom of the intake manifold, so post boost.
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Madess
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Report this Post05-26-2020 08:01 PM Click Here to See the Profile for MadessClick Here to Email MadessSend a Private Message to MadessEdit/Delete MessageReply w/QuoteDirect Link to This Post
Ok, so I fixed the misfire issue. That was a bad ICM. Now the car still runs like crap, I have a cvs log of me driving around the block. I am not sure how to post, or should I just cut out the the important parts as Spoon did?

I can email the file or try to post it on here, somehow.


Thank you for any help.
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Spoon
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Report this Post05-28-2020 12:01 AM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Madess:

Ok, so I fixed the misfire issue. That was a bad ICM. Now the car still runs like crap, I have a cvs log of me driving around the block. I am not sure how to post, or should I just cut out the the important parts as Spoon did?

I can email the file or try to post it on here, somehow.


Thank you for any help.


You can PM me the file. I'll see what I can do with it. Also on your misfire or poor performance, what grade of fuel are you using? I read an article recently about the need to use premium fuel in the 3800SC engine but I can't remember where I read it from. Nevertheless I do recall when I pulled my 3800SC from a 2000 GTP there was what appeared to be a factory sticker behind the gas fill flap that read "PREMIUM FUEL ONLY". So that's all I been using and there's a Royal Farms near me that has premium ethanol free which is another plus. More expensive but its not my daily driver and the tank is only so big.

If your not using premium you may want to look into this. I've never seen any mention of that sticker on this forum.

Spoon

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"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

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