Misfire and idle problems
Thread Starter
Teching In
Joined: Sep 2008
Posts: 32
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Misfire and idle problems I have had problems with backfiring at low rpm under load and a slight miss at idle ever since I did the EGR/AIR delete. What should I start looking at? Wires possibly?
2000 Trans Am M6
EGR/AIR delete, Lid, full exhaust w/ LT
2000 Trans Am M6
EGR/AIR delete, Lid, full exhaust w/ LT
I'm assuming you used block off plates on the intake and exhaust to close up the ports...
Thread Starter
Teching In
Joined: Sep 2008
Posts: 32
Likes: 0
The miss is not only at idle now it is also when there is a low rpm load (the times when you don't downshift and hit the gas) also it backfires sometimes then as well. There is a friggin retarded amount of codes. Did something get unplugged or what???? I have also added LTs and a Lid and new clutch and flywheel, master cylinder. What the hell is going on?
There is an EGR spark adder table that you want to zero
out, first off, since you're no longer punking the charge
with exhaust gas.
Long tubes bother idle fuel trimming usually. So there's
that. Try fixing the other stuff with the motor forced
open loop, tweaked to center, so that doesn't add to
your headaches.
Then a lightweight flywheel / clutch, that's prone to
raise (false) misfire detection. Start with doubling the
cylinder-mode misfire threshold values wherever they
are "sane" (i.e. not already 32000 or higher).
out, first off, since you're no longer punking the charge
with exhaust gas.
Long tubes bother idle fuel trimming usually. So there's
that. Try fixing the other stuff with the motor forced
open loop, tweaked to center, so that doesn't add to
your headaches.
Then a lightweight flywheel / clutch, that's prone to
raise (false) misfire detection. Start with doubling the
cylinder-mode misfire threshold values wherever they
are "sane" (i.e. not already 32000 or higher).
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Thread Starter
Teching In
Joined: Sep 2008
Posts: 32
Likes: 0
Should I always tune OL? Just for my 2 cents... 
Have all EGR adders, tables, etc... off or zeroed. Have the Misfire detection doubled now. Did seem to change a little of the misfire, but I can still definitely feel it miss right when I hit the gas when it is low rpm but full throttle. Or it will backfire also.
Have all EGR adders, tables, etc... off or zeroed. Have the Misfire detection doubled now. Did seem to change a little of the misfire, but I can still definitely feel it miss right when I hit the gas when it is low rpm but full throttle. Or it will backfire also.
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