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plugs Fuel fouled black 3800sc- CAUSE ? by Lou6t4gto
Started on: 12-18-2013 07:12 PM
Replies: 18 (420 views)
Last post by: Lou6t4gto on 10-03-2014 12:17 AM
Lou6t4gto
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Report this Post12-18-2013 07:12 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
The engine I got "to rebuild", 3800SC 1997 Riviera, ALL the spark plugs that CAME OUT, were Black wet fuel fouled (170K Miles) showing a code for MAF. COULD a bad MAF cause this on the plugs ? it was obviously either too much fuel or not enough spark, Had good compression. ( also had a code for #5 misfire) what else could it be ? The engine is now completely rebuilt, except sensors and coil pack. not in the car yet. Thanks
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Report this Post12-18-2013 07:28 PM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
It was not "not enough spark". Larry
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Report this Post12-18-2013 08:03 PM Click Here to See the Profile for sco77Click Here to Email sco77Send a Private Message to sco77Edit/Delete MessageReply w/QuoteDirect Link to This Post
The MAF is the primary control of the fueling, so yes a bad MAF sensor or wiring would cause that.

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Lou6t4gto
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Report this Post12-18-2013 11:27 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
IF "not enough Spark" what could be the Cause ? So, Before trying to fire up the new engine, Is the Any Way to" TEST" the coil packs (3) and ICM, and MAF to tell if they need replacing ? Can it be done with a multi meter, Or can Advanced or auto zone test them ? Thanks
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trotterlg
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Report this Post12-18-2013 11:41 PM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
It is either rich mixture, bad rings or bad valve stem seals. The coil pack will usually work or not work. They can cause misfires, but never cause all the plugs to be oil/fuel fouled. Larry
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Lou6t4gto
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Report this Post12-19-2013 12:25 AM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
"WHAT" would cause ALL the cylinders to run Rich ? (I wouldn't think ALL the injectors would leak at the same time) It's not oil, it's gas (That I do know)
MAF ? 02 ? Fuel Pressure Regulator ? When I got the car, it always started right up, would run smooth (when Not under load), But had "almost No Power" trying to drive it. had 170 psi in all cyl Before the rebuild.
I Probably "Should Have " solved the problem BEFORE pulling the engine, but .... that was then this is now. Is there a way to TEST the "suspect" components out of the car ?
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Report this Post12-19-2013 01:15 AM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
If it has been running that rich for that long then the cat is hosed along with the O2 Sensor. You have spent a lot of money on the rebuild, just replace the sensors related to mixture and be done with it. It is most likely not anything to do with spark. Larry
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Lou6t4gto
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Report this Post12-19-2013 01:34 AM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
That's What I want to do, which ones ? 02, already did coolant temp, does the intake air temp do anything, MAF, IAC ? just tell me, Which Ones . Thanks
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Report this Post12-19-2013 10:12 AM Click Here to See the Profile for darkhorizonSend a Private Message to darkhorizonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Maf's rarely fail all that much... You would best be off by cleaning the maf, then making sure there are no exhaust leaks.
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Report this Post12-19-2013 02:05 PM Click Here to See the Profile for TweederSend a Private Message to TweederEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm going through this right now as well, I have found a vacuum leak under the s/c that I hope is the problem.

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Lou6t4gto
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Report this Post12-20-2013 12:30 AM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
I was just looking at the Exhaust system that Came OFF of This Engine (from the 97 Riviera). I noticed that one of the 'Wires" on the 2nd Oxygen sensor (After the Catalitic Converter) was burned off. Could THAT have caused the "No Power" situation and the fouled plugs ??
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Report this Post12-20-2013 12:38 AM Click Here to See the Profile for TweederSend a Private Message to TweederEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Lou6t4gto:

I was just looking at the Exhaust system that Came OFF of This Engine (from the 97 Riviera). I noticed that one of the 'Wires" on the 2nd Oxygen sensor (After the Catalitic Converter) was burned off. Could THAT have caused the "No Power" situation and the fouled plugs ??


We don't use the after cat O2 in the fiero.

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Lou6t4gto
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Report this Post12-20-2013 01:06 AM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
I KNOW that. Could that have been causing the problem "when it was IN The Riviera" ? The Riviera "Did use it" for "Something". I haven't gotten it into the Fiero yet, I just don't want to run into the Same Problem AGAIN.
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Report this Post12-20-2013 11:17 PM Click Here to See the Profile for TweederSend a Private Message to TweederEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Lou6t4gto:

I KNOW that. Could that have been causing the problem "when it was IN The Riviera" ? The Riviera "Did use it" for "Something". I haven't gotten it into the Fiero yet, I just don't want to run into the Same Problem AGAIN.


I don't think so, but you would think its possible if the computers looking for a certain perimeter from the second o2 and is giving the wrong fueling/spark. But I think it would only cause a check engine light.

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86 SE Convertible 3800sc 4t65e HD.

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1fast2m4
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Report this Post12-21-2013 07:01 PM Click Here to See the Profile for 1fast2m4Send a Private Message to 1fast2m4Edit/Delete MessageReply w/QuoteDirect Link to This Post
the 2nd O2 sensor is just there to verify that the Cat is working, it's the 1st O2 that is affects how the engine runs

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1986 SE 3800SC/4t65eHD (12.871@104.96) I'll Sell it if you like
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Lou6t4gto
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Report this Post12-21-2013 07:21 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
ok, that eliminates that ! It "DID" "Act" like it had a Plugged Converter or muffler, but it threw the MAF code and misfire on #5. Now it has ALL new internals( with the exception of Rods and Pistons) crank/balancer, rebuilt Super charger, temp sender, plugs, wires, rebuilt TB, water pump, Belts and tensioners, so, I guess about the only "suspects" left are MAF, TPS, 02 sensor, MAP.
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Lou6t4gto
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Report this Post10-02-2014 07:00 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
in the end, it WAS the MAF. just to close the thread.
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Report this Post10-02-2014 09:15 PM Click Here to See the Profile for TweederSend a Private Message to TweederEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Lou6t4gto:

in the end, it WAS the MAF. just to close the thread.


Dirty or NFG?

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86 SE Convertible 3800sc 4t65e HD(2002), Gen V, 3.5 pulley, SD headers

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Lou6t4gto
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Report this Post10-03-2014 12:17 AM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
NFG
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