I have a 1988 Camaro Base Model with a 305 TBI.

Runs fine when cold start. But after warming up it idles at 550 in any gear. And struggles to run at 560. Most of the time I have to baby it to stay running.

I have new plugs, wires, cap, rotar, TBI freshly rebuilt, New fuel pump, New Fuel filter, Fuel lines have plenty of pressure and flow. NO BLOCKAGES.

I need help. Doesnt like running by itself without me babying the throttle.

-Meagleson

 

IAC may be stuck a bit. I'd check the timing. Retarded timing can cause the rough idle and stalling. If the timing isn't an issue, and you clean out the IAC, you can always tweak the idle air screw (gotta punch through the tin cap on the throttle body). I had to do that with mine. I would aim for something on the 650rpm range when totally warmed up in gear.

Other idea would be to double check your spark plug wires. Make sure they're all going to the right place, that the cap is on correctly and such. Any sort of off-by-one problems could have caused secondary issues with when you set the timing after putting the new cap on.

 

Thanks for the location of the IDLE adjustment...Just thought there wasn't one haha..

But no the wires are fine. No timing issues...Just a rough idle when i come to a stop or let off the gas to go to brake when in traffic.

Runs like a top if i dont let off the gas or it idles down lol....

Whats best way to punch through the TBI thing without damaging anything?

 

Just use a skinny screwdriver then a slightly bigger one to get the hole big enough to work with .. It's not very thick. You wont hurt anything. It should be on the driver side of the throttle body, facing the front of the car if i remember correctly.

You'll have an immediate change in engine noise while tweaking it, but you'll want to put it in gear after each change to see where it sits in gear. Too high and you will start having issues with braking, obviously.


edit: obviously, they thought nobody should need to mess with this ...but if you checked everything else, then there is little choice but to assume something has grown tired over the years and this tweak is now necessary. Mine has been altered for 4+ years. Without it, i can't shift into reverse without stalling due to the rpm's dipping far too low.

What i did notice that was interesting was with my now dead timing light. It was a digital timing light that reported the rpms and such. The rpm on the light was 100+ lower than what the dash said, and the dash was basically on the correct line that it should be on when in gear and stopped. I dont know if maybe some rpm sensor is tired or malfunctioning slighty or something and the ECM is not seeing the correct rpm or if that even matters. But what i did was set the idle air to give me the rpm on the timing light that it should be getting and things ran fine from then on (provided i didn't retard my timing a lot for inspections)

 

Nice...Thanks a lot...Im gonna try this once it warms up a little outside...Still 8 degrees out hahaha...

Um I do believe my Tach is working correctly. Only gauge ive ever hada problem with is the Speedo sticking due to a dry cable :\

But Id check your plug connections on your Distrub Cap...Mine was corroded....Just a thought though

Thanks for the help i greatly appreicate it!