misfires

[Tommy V]

Hey guys,anyone ever get random misfires.Started after putting my rxt clutch in but have done done 3 crank relearns.Thought it could be plugs because i had a problem with my 2step but its inhooked now and still getting misfires at different cylinders.Has new plugs now.Just dont what elese it could be.

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[Reds197]

Is it in the upper rpm range? If you have new plugs and its on random cylinders its not uncommon to turn it off in the tune.

 

[Tommy V]

Is it in the upper rpm range? If you have new plugs and its on random cylinders its not uncommon to turn it off in the tune.

No i dont think its upper rpm range but not 100%sure,car dont feel like it misses under hard load,rough starts on cold start and idle is pretty rough.I have had imrc problems before,they were sticking open or i believe.Could turn them off in the tune but good to have when u have a misfire to locate it.Didnt start until after clutch,never had a misfire until then.

 

[dubster99]

No i dont think its upper rpm range but not 100%sure,car dont feel like it misses under hard load,rough starts on cold start and idle is pretty rough.I have had imrc problems before,they were sticking open or i believe.Could turn them off in the tune but good to have when u have a misfire to locate it.Didnt start until after clutch,never had a misfire until then.

Can you datalog IMRC position to see what they're doing at idle?

 

[JennyStang]

Sound like something is f'd up your car. Have you tried going to stock and reloading tune? Long shot but maybe?

 

[Tommy V]

Can you datalog IMRC position to see what they're doing at idle?

Yes im going to do that tomorrow,their was another guy that had a shaft break inside the manifold and the butterfly was flopping around,because the shaft was broke he couldnt see it on the log,took manifold off and found it.He was getting misfires too,just weird all my misfires are on one bank.Going to look at that 02 real good also.

 

[dubster99]

Yes im going to do that tomorrow,their was another guy that had a shaft break inside the manifold and the butterfly was flopping around,because the shaft was broke he couldnt see it on the log,took manifold off and found it.He was getting misfires too,just weird all my misfires are on one bank.Going to look at that 02 real good also.

If the O2 was going bad or was bad, you'd see the afr on the gauge cluster either moving very slowly, or not moving at all. Also it'd throw a CEL if it was completely bad.

 

[Tommy V]

If the O2 was going bad or was bad, you'd see the afr on the gauge cluster either moving very slowly, or not moving at all. Also it'd throw a CEL if it was completely bad.

True if it was completly bad it would through a code,my a/f does move around a but at idle but alot of fi cars i see do this.Main thing is to look at difference between the two banks.I believe the imrc's can cause weird a/f also especially if its a problem on one side of the manifold.Ive seen imrc cause misfires and hope thata the problem,not much room back their and the engine drops a good bit during the clutch install.Guess i will see tomorrow lol.

 

[dubster99]

True if it was completly bad it would through a code,my a/f does move around a but at idle but alot of fi cars i see do this.Main thing is to look at difference between the two banks.I believe the imrc's can cause weird a/f also especially if its a problem on one side of the manifold.Ive seen imrc cause misfires and hope thata the problem,not much room back their and the engine drops a good bit during the clutch install.Guess i will see tomorrow lol.

I could see that, because it would be expecting one amount of air and getting another. You're right, you could've damaged something on the back of the intake during the clutch job.

 

[Tommy V]

I could see that, because it would be expecting one amount of air and getting another. You're right, you could've damaged something on the back of the intake during the clutch job.

Thats what im thinking,never had a misfire until that last clutch job.

 

[Reds197]

If it is only on a single bank I would not turn off misfires. I think you are correct starting with the imrc if its all the same bank.

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