i have an '83 cfi z-28..runs great...idles normal when cold and even after several miles...then it idles rough...like it's missing a cylinder...pulses. cleaned the iac motors...i think they're fine...do you think it could be the egr?.....coolent temp sensor is new. thanks for any thoughts...stan

 

How are the injectors flowing? Is the vacuum reading at either side the same? Are you certain that the ignition system is reliable?

 

the condition must be temp. triggered...it only happens after the car's been driven for some time...ignition is good-good wires, plugs, and new hei cap and coil. i'm going to look into the egr unit. do egr units need replacing often? is this usual?

 

¿Que? No, señor. Los balbos del EGR no son problemos generalmente. Pero, uno problemo del balbo no es muy dificile en el TBI.

OOPS! Too many Corona cervesas while celebrating another defeat of the French in North America...

EGR valves are not a normal maintenance item, but they do fail on occasion. Some last the life of the vehicle, some don't, like alternators or water pumps. But temperature sensitivity isn't one of their normal symptoms. If the cold idle is good, I'd put the EGR valve farther down the list of possibilities.

You may want to reopen the distributor and take a close look at the ignition pickup coil and reluctor. Measure the coil resistance, and inspect the reluctor closely for hairline cracks, excess rusting, etc.

 

thanks vader! happy may 5th! cinco de mayo!