TBI gurus come on in
 

92 Camaro RS 305 TBI

The issue I am having is the car will not kick down to normal idle, hot or cold, and if it does it runs like crap and the ECM bumps the idle back up. I did find a vac leak but i capped it off for now until I get enough line to fix it. The line that I capped it the one in between the TB and distributor that has its own 90 degree angle fitting coming out of the intake.

I cannot find any other vac leaks. I did replace the IAC thinking that was the issue but it didn't change anything. I have no codes

If anyone can point me in some kind of direction that would be great. This is my first TBI car.

Mike

there is a vac line between the distributor and the TBI?

it doesn't go to the distributor. there is a 90 degree fitting that comes out of the manifold that goes to a little vac canister than it splits into two. on line goes onto the firewall and the other is the line that goes down to the ball in the fender by the horn

the canister is the vac reserve for your hvac doors. you can rule out leaks there by pulling the line off that runs from the manifold and plugging it.

i had the same prob with my gmc change the ignition control mod and it will run perfect

it surged at idle like there was a vac leak and had a miss i changed the icm and it ran like it was a new truck

Chris I didn't even think of this. Is there anyway to test it. I don't want to waste any money I don't have to
Whats the best way to go about changing it? the last one i had to change was on a LT1

Thats what I did for the time being till I can get some more hose

i dont know if theres anyway to test it all i know is that that controls the spark and fuel some way some how

Whats the best way to pull it? I never did a distributor mounted one

its really easy to pull off just un plug the 2 plugs going to it unscrew the dist cap make sure you dont screw up the fireing order unscrew the icm and unplug the wire going under the dist and its out its really easy to do

great. hopefully that does it. The more I think about it the more it sounds like this could be the issue. i will keep you guys posted

the tbi's allways sound like a vacume leak if you put the open element air cleaner on it

Yeah I know. But I actually did find a really bad hose that the PO fixed with electrical tape lol. I'm gonna throw a ICM at it and hopefully that will do the trick

let me know how it works out

I was also advised that the pick up could be no good. a trusted source said he had the same problem with a car and it wound up being the pick up so i am debating swapping a distributor

Swapped the distributor and I am glad i did. the old one was all coroded on the inside. Set timing to spec and did a full tune up and she is running really good right now

im glad everything worked out