I know this is a group for Chevy trucks but I can't seem to find an answer anywhere for this problem. I just rebuilt a 3.1L Pontiac Grand Am motor , auto trans, and it idles great, but when I take it up to 55 it starts to shutter until I let off or stomp on the gas, I read two codes, MAP voltage too low and IAC inproper setting, I changed the MAP no luck, I don't have any vacuum leaks and at idle a vacuum test shows no probs, any ideas? TIA
3.1L
May 06, 2004
5 Replies
Year and type of injection system? Was the motor rebuilt with stock compression, stock cams and stock exhaust?
Doc
I'm also having trouble with my news server! To your reply Doc It's a 3.1L SFI with auto trans, all stock , bearings, cam, rings etc. Exhaust is stock. Now it's starting to idle a little rough, I was thing IAC maybe, any thoughts? Thanks
I'm also having trouble with my news server! To your reply Doc It's a 3.1L SFI with auto trans, all stock , bearings, cam, rings etc. Exhaust is stock. Now it's starting to idle a little rough, I was thing IAC maybe, any thoughts? Thanks
what sounds like a stupid question, but may kead to the trouble:
When it idles rough, does the brake pedal get 'harder' ?
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