Chevrolet Repair: Rough Idle 93 corsica, throttle plate, fuel pressure

Question
I have a 93 corsica 3.1L 140,000 miles. Hard to start when cold and will not idle until it warms up a little, then idles good. Runs good other than that. I replaced the idle air control and the throttle pos. sensor, still doing the same thing. What else could it be? It started out sputtering as times while driving, but no loss of power...

Answer
Hi Scott, the first thing to do is check fuel pressure, 35 psi or more. The next thing is to clean the throttle plate and bore with a old tooth brush and some carb cleaner. Open the throttle wide open to clean. I have had to raise the fuel pressure to 55 psi to get them to run cold.

Hope  this helps

Have a Nice Day          Mark