• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

Intermittent hot idle misfire

S

savage93

New member
I have a 2007 GP GT supercharged. The car has SSAC headers, 1.9 rockers, 3.5" pulley, custom intake, no cat, and no egr. I also am running 90# valve springs and an Overkill tune. Intermittently I'll get a hot idle misfire, will never happen cold and it goes away as soon as you touch the throttle. I'm running AL104's and new wires. This is the second set of plugs in 15000km. They're gapped at 0.045" . It did this last time Overkill was tuning it as I was leaving and he said there's no evidence of vacuum leaks. I'm starting to think of other possibilities before I go change another set of plugs and wires, maybe injector? It threw a P0300 the other night for the first time but before reading the freeze frame data I cleared it. Not sure where else to go with it?
 


I know you likely won't like this answer but misfires at idle are very common on modded 3800's.

I can feel them all the time, but it's never enough to trip the SES light nor come up on my hp tuners or aeroforce gauge.

I would try upping the idle by 100-150 rpms or so and it might go away all together. The warm idle of 650-700 might just be too low.
 
Mine has had the hot idle miss on startup since Ive owned it...did it stock and now does it modded I wouldn't worry about it mine throws a po300 but never shows up on the dash
 
Well at least I'm not the only one. It's done it as long as I can remember but it's only thrown a code once. And my hot idle is also pretty low, I never thought of upping it slightly.
 
You must log in or register to reply here.
Back
Top