Hello everyone , I have read a lot of info from this forum but don't post a lot.. I have a 1994 camaro with an lt1 I picked up for cheap .. I decided I'm going to race the car so I started doing bolt on mods to it. I had the intake ported, long tubes , bbl 58mm throttle body with a 58mm nitrous plate from nitrous outlet. And a couple other stuff but I got the car together and when you start it the idle shoots up to 3500rpm and stays there, if I stab the throttle really quick it will drop down to 1500rpm and another problem is when you give if a little throttle it falls on it's face at first. There is a check eng light so I scanned the system and it has a tps code and a mass air code. So I'm going to assume the mas air code is prob why it falls on it's face when you give it a little bit of throttle. But the high rev I'm kinda stuck on .. I replaced the tsp last night but it didn't change anything so I'm not sure where to go from here ..any help would be greatly appreciated. Sorry for the novel I wrote ^^

 

Since it looks like you were doing some work on the intake and the surrounding area, have you checked for air/vacuum leaks? I had a vacuum leak that would cause my car to rev up to 3k RPM when I was stopped. I'd start there if you haven't already or go back over everything another time to be sure.

 

What, if anything, do you have connected to the nitrous plate? Is it gasketed on both sides?

 

As Fred asked,do you have gaskets on both sides of the tb and plate?I had a very small rip in one of my gaskets and the car ran Pig rich with a high idle..Start back from the begining and check for leaks.I see that you picked up a used intake manifold??My friend picked one up from Arkansas Porting 2 yrs ago,I did not even think to check and make sure the pipe plugs were still installed in the bottom of the intake,well turned out they did not re-install them and that created a high idle,lack of power and a BIG headache for me..If the tb gaskets turn out to be ok,and you find no vacuum leaks,you might want to pull the intake and make sure the plugs are installed..

 

My question is even more basic.... are the plate's nitrous and fuel connected connected to anything, or are they open?

 

Sorry guys my PC went down and I couldn't get on to reply lol .. Yes I have a gasket on both sides.. I have sprayed alot of cleaner around the intake and it doesn't change anything.. What weird is it idles high until you stab the throttle real fast and the idle will drop to almost normal.. And as far as the nitrous And fuel, yes I have the nitrous and fuel line hooked to the plate and there are no jets in the lines yet but I don't have any pwr hooked to the solinoids yet

 

Have you checked your throttle blades for smooth operation? Are they getting hung up in the bores close to closed?

 

Yea I checked the throttle plates .. I heard that BBK throttle bodies sometimes have a problem with getting stuck open just a little bit, so I checked them and they are 100% closed

 

I know my Holleys were like that. What's your current TPS voltage at 0%?

 

I believe the jets are required to form the seal for the -AN fittings. Try putting jets in the lines.

 

Ok guys I have spent the last few days messing with the car and I finally figured out what was up with the idle being high.. When I put my nitrous plate on I had to grind a little bit off the back of the water pump and also the iac housing .. I got a little carried away and grinded a tiny pin hole in the iac housing causing a leak and in turn a high idle .. It was a dumb mistake on my part but at least I figured it out ..thanks for all your guys help I really appreciate it..