Weird issues after installing SS M90 SC
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Posts like a Corvette
Joined: Jun 2008
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From: Cleveland, OH

I put the whole kit on my car today and at low idle the engine makes the whole car shake and the exhaust sounds different
then when you are in gear and hit the gas it really shudders then is fine from about 2000 RPM up
but then when you idle or under small acceleration the SES light starts flashing (I know thats not a good thing) then once you hit higher RPMs it stops and the SES light is solid, haven't checked the codes its throwing yet
one other thing, the exhaust smells like fireworks, strange
then when you are in gear and hit the gas it really shudders then is fine from about 2000 RPM up
but then when you idle or under small acceleration the SES light starts flashing (I know thats not a good thing) then once you hit higher RPMs it stops and the SES light is solid, haven't checked the codes its throwing yet
one other thing, the exhaust smells like fireworks, strange
Joined: May 2006
Posts: 29,661
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From: Sheboygan Wisconsin






My guess is you have a rich code and possibly misfire. Sounds like a dead spark plug. Pull the plugs and inspect. Watch for black. Check over wires, and coils.
Thread Starter
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From: Cleveland, OH

I'll look over the wires sometime when its cooled down, it should't be a plug because there autolite 103s that were used for 3 months before I got the kit, maybe a wire
Plugs crack etc if dropped the right way. Never know til you pull them.
As for the running rough, two cylinders being swapped isn't that rough. Nice thing is you are rich and not lean. What pcm programming did you do in order to run it?
As for the running rough, two cylinders being swapped isn't that rough. Nice thing is you are rich and not lean. What pcm programming did you do in order to run it?
Thread Starter
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From: Cleveland, OH

scanned while I was out today, its misfiring on cylinder #1, so to start I swapped the #1 wire with one from another car, still misfiring
pulled the plug, looks ok but what the heck I'll swap it with cylinder #3, still misfiring on #1 only
so I grab the #1/#4 coil pack from another car, still misfiring on #1
here are the changes I made to the PCM
PCM
The L36 PCM currently in your car is setup for naturally aspirated. It doesn’t matter if you have an aftermarket PCM or stock. These are the changes that need to be made:
pulled the plug, looks ok but what the heck I'll swap it with cylinder #3, still misfiring on #1 only
so I grab the #1/#4 coil pack from another car, still misfiring on #1
here are the changes I made to the PCM
PCM
The L36 PCM currently in your car is setup for naturally aspirated. It doesn’t matter if you have an aftermarket PCM or stock. These are the changes that need to be made:
- PE TPS needs to be lowered. The car needs to enter fuel enrichment at 35%
- PE AF ratio needs to be lowered by 2.0
- Converter lockup needs to be raised by 5mph on all tables that do not read 255. and the TCC release needs normal shift tables under 3rd and 4th raised 9mph with 37.5, 43.75, and 50% raised to 255.
- Base timing for good fuel spark needs to be lowered under load to 16 degrees. Or taking out around 8 degrees usually works well.




