Ok, so lately, sometimes when I go to start my car, it doesn't want to idle. It starts ok but then the idle speed is really low and kind of drops off a bit and eventually will stall if you sit at a light too long and don't give it a little gas to keep the engine speed up. After it stalls it doesn't want to start back up and I have to crank it for a few seconds and then it slowly starts to run again.

After I drive it for a few minutes though, it seems to idle ok. What could cause this? It's a 92 with a cammed LT1 btw.

 

Anyone?

 

lazy IAC?

 

Have you checked for any codes stored in the o.b.d?

 

When was it AND the throttle body last cleaned?

 

Pull it and clean it. Carefull with the gasket when taking it off.

 

Horsepower844182: A problem like the one you describe can have many potential causes. Forum members will give you suggestions from their experiences and you MAY get lucky and find your problem. If you are NOT lucky, you will spend a lot of time some folding $$$ on parts that you do not need. I would suggest you find someone with a scan tool and see what is actually happening with your sensors as the problem is experienced. This will allow you find the root cause and solve your problem. Good luck on the issue and let us know what you found to be the root cause.

Bob (#1900 and going for 2000)

 

Seems to me that these C4 motors are all having idle issues but every one is different. One cause of the problem is that GM used aluminum and steel in combination on these motors. They both expand differently when heated aluminum expands further than steel and dissapated heat faster. In most cases ranging between many different brands of cars after many years of use the gasket between the aluminum and steel fail.

One suggestion that I can offer is fairly inexpensive, effective and has proven successfull for me in the past. Go to your local parts store and buy a Fel-Pro Intake manafold gasket kit. Costing you a MAX of $20.00 then go to Walmart and buy a few bottles of brake and parts cleaner and 150 grit sand paper $10.00 If you can afford it engine degreaser. Then when you get time pull the enitre Intake manafold off the car draining the cooling system first. Clean all gasket mating surfaces with the sand paper then use the parts and brake cleaner on the throttle body and degreaser on the intake. Blow out all bolt holes with compressed air clean the bolts with a wire brush and reassemble the intake using parts cleaner on the gasket surfaces making sure the surfaces are dry and clean, use engine oil or 3 in 1 oil on the bolts so you can get s consistant torque on them. Be careful when starting the bolts in the aluminum because they tend to cross thread easily and dont over tighten the bolts as the soft aluminum strips easliy.

Good Luck and have fun