Ok, here is my situation. I am new to Fiero's, swaps, 3800's, & ECU's. But I have done tons with SB chevy stuff so the mechanical part is not an issue. Anyway I have a 87 fiero with a 98 GTP ECU (programed to match the mods by Loyde @ Fast Fieros), 2002 GTP Series III 3800sc (with ZZP exhaust Logs, XP cam & springs, N* TB, 3" exhaust), 5 spd Getrag (Mstangbware you did part of this swap). I recently bought this car with the swap complete. The motor runs but throws a P0336 code (crankshaft position sensor error). The previous owner changed the crank sensor before I purchased it and it didn't fix anything. It runs pretty rough so the first thing I did was look everything over. I found that all the plugs were fuel fouled (one finger tight), 2 plug wires burnt, O2 sensor not even finger tight, oil smelled pretty gassy & multiple corrodid connections and grounds. I fixed those issues. I have done tons of research before attemping to do anything further with it. I just purchased HPTuners program to start messing with it. One thing I keep running into is that it needs a CASE Learn done. I contacted the previous owner and asked if this has ever been done. He stated he has never done one... So obviously I think it needs one done to it, which i can do now with the HPTuner. I guess my question is does the code need to be cleared before a CASE Learn is done? And do you think the case learn will fix the issue? Are there other things I need to look at that may also be part of the problem...
Thanks for the help...
------------------ WInning Isn't Everything, Wanting Too Is...
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02:28 PM
PFF
System Bot
1fatcat Member
Posts: 1519 From: Zimmerman, Mn Registered: Dec 2010
Do the case learn. Try it with the code stored, then with the code cleared if needed. You can try clearing it first but it may come right back before you can initiate case learn.
As far as I know the Case learn is for they detection of knock. If you are throwing that code then there will be no retardation of timing when there is knock. I pretty sure it doesn't have anything to do with fueling. Get a wideband o2, you will probably have to do some extensive modification to the pcm.
I recently bought this car with the swap complete. The motor runs but throws a P0336 code (crankshaft position sensor error). The previous owner changed the crank sensor before I purchased it and it didn't fix anything. Thanks for the help...
You might want to check the crank sensor again. Sometimes NEW parts are bad. Also, you should join HPTuners forum and Club GP (Grand Prix) forum and ask there because there are many more resources their for the 3800 tuning. A fresh tune will probably be good too, warmer climate and altitude differences warrant a change to the tune.
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02:53 PM
1fatcat Member
Posts: 1519 From: Zimmerman, Mn Registered: Dec 2010
Case learn is to teach the PCM where TDC is on cyl 1, relative to the crank position. The PCM uses this value to adjust ignition timing. It's pretty important.
[This message has been edited by 1fatcat (edited 03-11-2011).]
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02:57 PM
Fiero Racer 64 Member
Posts: 58 From: Hastings, Ne USA Registered: Dec 2010
I am on HPTuners forum and also 3800Pro.com. I though I would start here with the fellow Fiero guys beings you all are more familiar with my set up. I'll definatly go to the other forums and check with them also if the info I get here doesn't seem to help. I know from what i've read on those other sites is if you change ECM, a sensor, or anything with the timing of the crank or cam they say a CASE Learn has to be done.
I do know I've tried to clear the code with just the standard scanner and it works for a short time then the code and engine light comes back.
Hopefully this weekend I can attempt to do the CASE Learn. I would be estatic if it works and the motor starts running good. Then the real fun of playing with the HPTuner Editor begins.... :-)
If that doesn't do it them I'll try changing the crank sensor and check the balancer to make sure it hasn't been damaged...
Thanks for input... If you think of anything else please let me know...
Also I was told the harness was done by ... "Wiring harness is from chris (dmentia on pff)." I can't find anyone with that user name in the member list. I've also searched the archieves for posts by.. but nothing.. Any help is appreciated...
------------------ WInning Isn't Everything, Wanting Too Is...
[This message has been edited by Fiero Racer 64 (edited 03-10-2011).]
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07:59 PM
Mar 11th, 2011
Darth Fiero Member
Posts: 5922 From: Waterloo, Indiana Registered: Oct 2002
The GM service manual says this regarding the CASE Learn:
quote
"CASE" means: crankshaft angle sensor error. A crankshaft variation relearn must be performed if: -A diagnostic trouble code of P1336 is present. -The computer has been replaced or re-programmed. -The crankshaft position sensor has been replaced. -The engine, harmonic balancer, clutch, or flywheel have been: disassembled, removed, or replaced.
The crankshaft position variation learning feature enables the computer to compensate for part manufacturing tolerances. This allows the computer to accurately detect an engine misfire throughout the engine RPM range. The learning process is stored in the computer's memory and does not have to be repeated unless one or more of the above conditions are present. To perform the relearn, proceed as follows: Connect a scan tool to make sure there are no trouble codes stored in the computer's memory. If there is any power train trouble code other than P1336 (Crankshaft Position Variation not learned), the computer will disable the relearn function until the problem that caused the code has been eliminated. Also, make sure that the engine coolant (check it when the engine is cold) and oil levels are at an acceptable level.
The CASE Learn has nothing to do with the Knock Sensor or fueling.
I know the engine doesn't run "right" with a code P1336 being set. Just doesn't seem to start as fast or run as smooth; this is just what I've experienced myself. I've been told by other tuners that not doing a CASE Learn and it being needed (ie: code P1336 set) can create some issues at WOT concerning timing advance. I don't know if there is any truth to these statements or not.
-ryan
------------------ OVERKILL IS UNDERRATED Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com
[This message has been edited by Darth Fiero (edited 03-11-2011).]
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01:51 AM
2002z28ssconv Member
Posts: 1436 From: Orlando, FL Registered: Jun 2005
Don't trust that anything done recently was done correctly.
I don't want to hate on another Fiero owner but it sounds like some other simple things might not have been done the right way.
Hopefully you get yours tuned well. I'm still chasing a little bit of KR in mine. Shielding the knock sensors with Dynomat has really made a difference.
I think the resonation from the Flowmaster 80 was being picked up by the knock sensors.
[This message has been edited by 2002z28ssconv (edited 03-11-2011).]
I wouldn't say that. The knock sensor funtions all on it's own regardless of what the case learn value is. HOWEVER, if case learn is off, it can cause too much ignition advance (or retard) and cause pre ignition and high knock sensor activity. So it can affect the activity that the knock sensor sees, but it has no effect on how the knock sensor functions. Make sence?
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05:31 PM
PFF
System Bot
Darth Fiero Member
Posts: 5922 From: Waterloo, Indiana Registered: Oct 2002
I'm not aware of this, as it is not mentioned in the service manual under "ACTION TAKEN WHEN CODE SETS", but it does makes sence. If the code is set, that means the PCM doesn't know where TDC is reletive to crank rotational degrees. If it can't correct the timing accurately, it probably won't even try.
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08:14 PM
2002z28ssconv Member
Posts: 1436 From: Orlando, FL Registered: Jun 2005
Very serious. I was getting 10 degrees (and climbing) at WOT by the time I hit 4500 RPMs (and then I would get off the gas). Now it's down to less than 3, WOT past 5500 RPM. They actually sell a kit for the Grand Prix crowd that covers the knock sensors and the output housing of the auto transmission.
Sorry for the tangent. I was just trying to make you feel a little better knowing you're not the only one scratching his head over tuning woes.
The muffler is about as tight to the engine as it can get and not hit the drivetrain. I didn't alter the trunk at all... yet...
[This message has been edited by 2002z28ssconv (edited 03-11-2011).]
Don't take this wrong guys, but I see some names associated with tuning. Do tuners do a case learn before tuning? I don't do tuning, but I know how important case learn is on a stock engine, so I would have to assume it's even more important on a modded engine. It's the equivalent of setting the base timing on an old vacuum advance distributor ignition system.
On my first venture into 3800's I had someone tune the car for me. I wasn't getting any kr ever, so I thought sweet, good tune. The guy thought everything was fine. After awhile I started to chip pistons. I had Scott look at my pcm and he found that it needed a case learn. We did that and then +8* of kr started to show up. Maybe it was just a coincidence...
I can see putting dynamite on the transmission, but putting it on the knock sensor has to be the most asinine thing I've seen. You are just treating the symptoms and not the problem.
On my first venture into 3800's I had someone tune the car for me. I wasn't getting any kr ever, so I thought sweet, good tune. The guy thought everything was fine. After awhile I started to chip pistons. I had Scott look at my pcm and he found that it needed a case learn. We did that and then +8* of kr started to show up. Maybe it was just a coincidence...
I can see putting dynamite on the transmission, but putting it on the knock sensor has to be the most asinine thing I've seen. You are just treating the symptoms and not the problem.
But was it tuned first without a case learn? If so, the entire tune was "out of tune". So performing a case learn later would throw all of your timing tables off (probably injector timing too). Bottom line is, when tuning, step 1 is a case learn. From there, do whatever you want.
Case learn teaches the PCM where the exact point is on the crank's rotation relative to top dead center on cylinder 1. From there, the PCM knows when and where the other cylinders are and when they fire.
Remember, the PCM can't see the pistons or where they are in their stroke. It can only see the rotational degree of the crankshaft. So it needs to set timing off of the crank position.
You know how "they" say ignition timing is not adjustable on newer engines? Well, this is why. The case learn is how you set timing (kind of). It's how you teach the PCM where TDC is on cyl 1 (the PCM's referance cylinder), from there the PCM takes over and decides when and where the ignition timing should be.
It really is the equivalant of setting base timing on a vacuum advance distributor ignition system.
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12:00 AM
darkhorizon Member
Posts: 12279 From: Flint Michigan Registered: Jan 2006
You can explain it to yourself by asking this question...
How do you detect a misfire, and how/is it different from detecting knock?
quote
It really is the equivalant of setting base timing on a vacuum advance distributor ignition system.
That is completely and utterly wrong, it has no realation to ignition advance. Total advance, is total advance, no matter what base/additional timing is, and it has nothing to do with crankshaft/piston position.
[This message has been edited by darkhorizon (edited 03-12-2011).]
Are you sure? The cam spins at half the speed of the crank, so basing the timing off the cam would be pretty inaccurate compared to the crank.
Found it in this book http://books.google.com/boo...=X&oi=book_result&ct =result&resnum=1&ved=0CBgQ6AEwAA#v=onepage&q=The%20cam%20sensor%20signal%20alerts%20the%20PCM%20when%20the%20number%20one%20cylinder%20is%20at%20TDC.&f=false
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01:57 AM
Darth Fiero Member
Posts: 5922 From: Waterloo, Indiana Registered: Oct 2002
How do you detect a misfire, and how/is it different from detecting knock?
You're joking, right? Do you mean to tell me you don't know the difference between misfire and knock detection?
Knock detection has been around long before misfire detection has. GM EFI systems are designed to detect knock (detonation) using a MICROPHONE attached to the engine. It LISTENS for detonation. When detonation is detected, as a response - the computer retards ignition timing until it goes away (within the limits imposed by the programming; ie: there is a limit as to how much timing can be pulled, how fast it is pulled, and how quickly "normal" timing advance is restored after the detonation ceases). The knock detection system works purely by sound and it has always been done this way by GM. Detonation must first occur before action can be taken by the computer to retard timing.
Misfire is detected by the computer looking at crankshaft position and calculating the time it takes for the crankshaft to rotate to the next firing event. If a cylinder misfires, the crankshaft's rotating speed will slow down momentarily and the next cylinder firing event will not occur within the expected time the computer thinks it should, and thus a misfire event will be recorded. The computer only uses the crankshaft position sensor to detect misfires, it does not use the knock sensor for this at all.
A CASE Learn is done so the computer can "learn" the different production and part manufacturing tolerances for the specific application it is being used in. Misfire detection was used on GM engines long before the CASE Learn function existed. GM introduced the CASE Learn function so the system could gain accuracy in the way it can detect misfires.
-ryan
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12:31 PM
Darth Fiero Member
Posts: 5922 From: Waterloo, Indiana Registered: Oct 2002
On my first venture into 3800's I had someone tune the car for me. I wasn't getting any kr ever, so I thought sweet, good tune. The guy thought everything was fine. After awhile I started to chip pistons. I had Scott look at my pcm and he found that it needed a case learn. We did that and then +8* of kr started to show up. Maybe it was just a coincidence...
You didn't have a certain guy in Texas tune your first 3800 PCM for you, did you? At one point this certain person in question was making changes in the PCM's programming that was severely crippling the PCM's ability to retard timing and admitted to doing so on this forum.
By "chipped pistons" do you mean broken piston ring lands?
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12:36 PM
Darth Fiero Member
Posts: 5922 From: Waterloo, Indiana Registered: Oct 2002
Do tuners do a case learn before tuning? I don't do tuning, but I know how important case learn is on a stock engine, so I would have to assume it's even more important on a modded engine.
A CASE Learn is only required if:
-A diagnostic trouble code of P1336 is present. -The computer has been replaced or re-programmed. -The crankshaft position sensor has been replaced. -The engine, harmonic balancer, clutch, or flywheel have been: disassembled, removed, or replaced. (crankshaft should be added to this list)
In a nutshell: if you went to the junkyard and got an engine, computer, and transmission out of the same vehicle (ie: a Grand Prix or other donor car) and installed all of that into a Fiero; you wouldn't necessarily need to have a CASE Learn done. However, if you got a PCM from a different car and went to use it on your engine, you would most likely need to have a CASE Learn done. Sending your PCM off to have it reprogrammed for your swap does not automatically mean it will need to have a CASE Learn done once you get it back. It depends what tuning software is being using to tune it.
I've tuned hundreds of PCMs for customers over the years, and as long as the PCM sent to me came out of the same vehicle their engine did, they usually don't need to have a CASE Learn done. That's because the tuning software I use doesn't erase the stored (previously learned) CASE Learn information. Some tuning software may erase this information. If you are changing any of the above listed components from what they were stock (ie: if you've removed the automatic trans and installed a manual in its place, or replaced the crank sensor, etc), you should have a CASE Learn done.
Currently there is no way for a mail-order tuner to do a CASE Learn without having your car. (It would be nice if someone could hack the stock code so a CASE Learn would automaticlly be ordered once the engine warmed up for the first time after the PCM had been reprogrammed, but so far nobody has been able to step up and do that.) If someone is doing a hands-on tune on your car and a CASE Learn has not yet been done (and it is required), it should be performed before the first test drive (can be done after the first round of custom settings have been programmed to the PCM).
The cam AND crank sensors are both used by the PCM to determine where TDC of No.1 cylinder is. The PCM cannot determine where TDC of No.1 cylinder is (between compression and power strokes) without a cam sensor, and the engine won't run without a crank sensor signal.
On older DIS applications that were not SFI, the ignition module could determine where TDC of No.1 cylinder was by the way the crank sensor reluctors were designed. But it didn't know if it was TDC between the compression/power strokes for No.1 cylinder or the opposite cylinder in the firing order because there was no cam sensor input. The camshaft determines if a cylinder is at TDC between compression/firing strokes or if it is at TDC between exhaust and intake strokes.
The cam sensor tells the computer when cylinder No.1 is at TDC between a compression and power stroke, and it uses this information to determine when to fire injectors sequentially.
-ryan
[This message has been edited by Darth Fiero (edited 03-12-2011).]
You didn't have a certain guy in Texas tune your first 3800 PCM for you, did you? At one point this certain person in question was making changes in the PCM's programming that was severely crippling the PCM's ability to retard timing and admitted to doing so on this forum.
By "chipped pistons" do you mean broken piston ring lands?
His name was Bill and he had a friend Dave with him. He never tuned a pcm that wasn't in a W body before. The PCM did come from a different car than the engine. I started to smash spark plugs. It would always happen if I did back to back of driving it hard and it would happen at high rpm in 2nd or 3rd. After awhile I started to lose compression and pulled the heads off. This is what I found. 4 pistons had pieces missing.
His name was Bill and he had a friend Dave with him. He never tuned a pcm that wasn't in a W body before. The PCM did come from a different car than the engine. I started to smash spark plugs. It would always happen if I did back to back of driving it hard and it would happen at high rpm in 2nd or 3rd. After awhile I started to lose compression and pulled the heads off. This is what I found. 4 pistons had pieces missing.
Yup, popped ring lands. I usually see that happen because of too lean AFRs and/or too much boost; not so much because of detonation (I'm not saying detonation couldn't pop ring lands). Did you hear the engine detonating when you were running it before this happened?
Do you happen to know what your commanded timing advance was before the CASE Learn and then what it was after you had the CASE Learn done?
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03:00 PM
PFF
System Bot
Fiero Racer 64 Member
Posts: 58 From: Hastings, Ne USA Registered: Dec 2010
Great discussion guys... I hate to interupt, but i just went and tried to do a case learn on the car. I let the motor warm up to160-180 degrees and scanned it.. The P0336 code obviously came up. I cleared it, and did all the steps neccassay to perform the learn. I hit the "Begin" button (HPTuner Scanner) to start the process. It says then to steadily increase RPMs till fuel cut off. When I started to do this a message came up RPM High and the "Begin" button comes back... I did it 5-6 time varing the rate that I increase the RPMs but it didn't seem to matter. What is it trying to tell me? Also I have to rev it above almost 6000 for it to cut off. The directions say 4000-5000 rpms it should shut off for the CASE learn. Any one using HPT know what is causing this?
Also you talk about a P1336 code.. I get a P0336 code... whats the difference???
Very Frustrating!!!! LOL
Thanks for the help...
[This message has been edited by Fiero Racer 64 (edited 03-12-2011).]
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03:08 PM
Darth Fiero Member
Posts: 5922 From: Waterloo, Indiana Registered: Oct 2002
Great discussion guys... I hate to interupt, but i just went and tried to do a case learn on the car. I let the motor warm up to160-180 degrees and scanned it.. The P0336 code obviously came up. I cleared it, and did all the steps neccassay to perform the learn. I hit the "Begin" button (HPTuner Scanner) to start the process. It says then to steadily increase RPMs till fuel cut off. When I started to do this a message came up RPM High and the "Begin" button comes back... I did it 5-6 time varing the rate that I increase the RPMs but it didn't seem to matter. What is it trying to tell me? Also I have to rev it above almost 6000 for it to cut off. The directions say 4000-5000 rpms it should shut off for the CASE learn. Any one using HPT know what is causing this?
Very Frustrating!!!! LOL
Thanks for the help...
Whatever is causing the code P0336 needs to be addressed before you attempt to do a CASE Learn. Doing a CASE Learn now will NOT fix whatever is causing the P0336 code to set.
P0336 sets if the PCM detects a problem with the 18x crank sensor circuit. The crank sensor on these engines actually consists of two sensors in one that monitors separate sets of reluctor rings on the balancer. On the balancer, there is a ring with 3 unequal size notches (this is for the 3x portion of the sensor) and there is another ring that has 18 equally sized notches in it (this is for the 18x portion of the sensor).
When code P0336 sets, the PCM will use the 3X reference signal circuit for fuel and ignition control.
The 18x signal comes out of the crank sensor's pin B and travels on a yellow wire to pin G of the ignition module. The ignition modules outputs this 18x signal on pin C where it travels to PCM terminal C1-9 (blue connector) on a light blue wire with a black stripe.
I would check these wires and make sure they are not cut, broken, shorted to ground or anything else. Also check the pins in the connectors to make sure they are not corroded or have bad connections. A damaged 18x reluctor ring on the balancer can also cause this issue, and so can a bad ignition module or bad PCM.
I would start by checking the wiring and connections/terminals for this circuit before you do anything else.
-ryan
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03:23 PM
Fiero Racer 64 Member
Posts: 58 From: Hastings, Ne USA Registered: Dec 2010
Originally posted by Darth Fiero: Did you hear the engine detonating when you were running it before this happened?
Do you happen to know what your commanded timing advance was before the CASE Learn and then what it was after you had the CASE Learn done?
I didn't hear anything abnormal. I don't know what they did, for sure. For some reason I think they bumped timing up 2* at WOT because I wasn't getting any kr. I had a 3.4 pulley, 4" intake and a 3" high flowing exhaust. I did the swap 5 years ago so I had no idea what was going on tuning wise. I think the main problem Scott found, it was too lean. I wish I knew then what I know now...
So I assumed that knock protection was tied into the the case learn problem, I guess I was wrong? Maybe those guys did something funky in the tune like that guy from texas you mentioned above.
Thanks Ryan... I will do that and let ya know what I find out... :-)
(I may be off base again...) I believe you need to put your car in Park. Since you have a manual you will need to ground two wires from the PCM, so it thinks its in park. Then you will hit the fuel cut at 4,000 rpm like you are supposed to.
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03:49 PM
Fiero Racer 64 Member
Posts: 58 From: Hastings, Ne USA Registered: Dec 2010
Justin... I think I may have read that some where to... Didn't know if that still needs done or not.. Also I pressed the brake the whole time but does that really do anything.. I don't think thats tied through the ECU is it? Same thing with the Park Brk... I guess I should have asked this before trying it... Yeah it scares me reving it that high...
Ryan... Is this true?
Thanks again guys for the help..
[This message has been edited by Fiero Racer 64 (edited 03-12-2011).]
pin 18 on c2 (black/white wire) and pin 16 on c2 ( white wire) must be gounded for the pcm to think its in park. then pin 30 on c1 (purple) is the brake signal, it needs to see 12v with the brake not depressed then no voltage with the brake depressed. ryan helped me out a while ago so i could do my case learn.. so it needs to see the regular brake but not the parking brake and then grounded wires for park signal.. i just read your reving to 6k? you didnt change any rev limiters did you? i believe your looking for the fuel cut rev limiter in park/neutral table
[This message has been edited by black88fiero (edited 03-12-2011).]
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04:12 PM
Fiero Racer 64 Member
Posts: 58 From: Hastings, Ne USA Registered: Dec 2010
i just read your reving to 6k? you didnt change any rev limiters did you? i believe your looking for the fuel cut rev limiter in park/neutral table
No I haven't changed anything yet. I just want to get it so its running smooth and not throwing a P0336 code... before I do any changing. Also Im still trying to figure out my HPT...LOL I'll look for the "park/neutral table" and see what its set at... I'll go ahead do as you suggest also as far as grounding and 12v supply to pins...
im not to familiar with hpt so i dont knwo what the table is called. but if you havent changed it and your computer was never touched i say it hasnt been changed.. the two park wires get grouned and the brake signal is 12v. do not confuse them and switch up the signals.. you could then kiss the pcm good bye, just want to put emphasis on that..
