TB probelm
Thread Starter
10 Second Club
Joined: Jan 2010
Posts: 2,317
Likes: 20
From: Hurley, VA
TB probelm I recently bought a used 85mm professional products TB and I can't get my car to idle down. I had to adjust the cables to get WOT but when I unhooked the cables it still idles up. You can rev it up and it'll idle on about 2200 for a few seconds and then slowly go back down. You can drive it without giving it gas. What could cause this ?
Thanks
Thanks
If it was idling fine before and the only thing you changed was the TB, then the TB is allowing the engine is getting more air than it should at idle. Fully closed, is there room around the TB blade for air to get through? One way to check is to take the TB off, if you can a decent amount of light around the TB blade (more than stock) that's would be your problem. It could also be a leak where the TB meets the intake manifold.
Thread Starter
10 Second Club
Joined: Jan 2010
Posts: 2,317
Likes: 20
From: Hurley, VA
Well another problem with the throttle body was that the lid didn't want to go back on I had to run it what little i did half on and half off. It came with a solid aluminum spacer with a red gasket that goes between the Tb and the spacer. Is it possible that spacer isn't even suppose to be used for that throttle body. I even trimmed the factory bellow and everything. Still didn't want to fit. I'll have to put it back on and start playing with it. Thanks
I've had two ported throttle bodies that did the exact same thing, even after the car was dyno-tuned. Come out of gear to idle to a stop, and the car sits at about 1800rpm, then slowly idles down. IAC counts are zero and everything is functioning properly...my car just doesn't like ported throttle bodies. Both were done by reputable P&P guys, too.
make double sure you re-installed the red rubber o-ring on the iac sensor. we have had a few that were not put back on and the idle would also hang from the unmetered air.
