Originally Posted by jthorn9
See for an issue like this the IAC and TPS sensors are usually to blame, however I don't think it's the case, although it would still be a good idea to look them over.
I would start looking over the supercharger unit itself and make sure that the impeller is spinning freely with no obstruction. I know powerdyne isn't exactly known for making quality superchargers.
Now if both of those check out it could be a vacuum leak. It sounds like when the S/C is being slightly spooled at idel that the slight boost in vacuum could be blowing through a leak causing a short term loss in vacuum and poor idel. I had a similar problem in my 5.0 a long while back, the upper intake wasn't seated all the way to the lower which caused the idel problem. It was so minute that my boost/vacuume gague didn't pick up up, but a smoke test did.
Thank you for your insight! I was thinking possibly the same myself, I'll try to have a more rigorous vacuum leak test performed. TPS and IAC will also be checked out.
Also sorry fellas for being slow, cable outages. =[
List 'o mods:
Stock midpipe (For now, ****'s coming off ASAP, it was put on all ***** nilly to pass VA inspection and there's an exhaust leak at the driver side flange, I'll address that when I put my H pipe on since I'm in NC and we don't give a crap about emissions)
3.73 gears (Dunno why that would matter)
All the typical bling that's non mechanical (Rims/Cowl/Springs/Etc...)
Ummmmm, I think that's it. There's a fender-well intake, dunno if that's stock with the kit or not. It did have a raunchy air filter when I got the car, had that cleaned up.
Also, if it is a vacuum leak/tps/iac, then why does it not idle crazy when the AC pump is on?
Oh, and when my roommate had the S/C off of the car the other day he said it spun well and moved air good. We're not S/C experts or anything, but seems if there was an issue it would have resisted being turned by hand. (Had to pull it to change a crappy Advance alternator)
And TBH I'm not 100% certain that the car has been tuned, good at least. I figured it would run like total *** under full throttle and probably have blown up by now if it hasn't been tuned. No wideband to report on air/fuel behavior, but it runs like a champ other than the idle, no knocks or anything. Where do I look for a chip, the kick panel by the passenger's feet?
Could timing be an issue?