My 1985 Corvette would stall or shut off occasionally in stop and go traffic or when coming to a stop. There were no fault codes and no Service Engine Soon light. I changed just about everything related and I was about to give up when I read an old post on the web that explained my problem. It ends up that my EGR valve was either stuck open or the diaphragm was leaking. The EGR Valve needs to be closed and not allow any air when decelerating or at idle because if unaccounted air is coming through the intake manifold the gas/fuel air mixture will be thrown off and the computer will not know how to correct the ratio, and the car will stall or shut off. Also, after replacing the EGR valve and swapping the EGR Temperature Sensing Switch, I made the mistake of screwing it all the way in, causing the switch to be closed all of the time. This caused a SES light during a cold start. The SES light would not come on during a warm or hot engine start. The fix was to back out the EGR Temp Switch about two threads verifying with a meter that it was no longer closed.
A couple of more things not mentioned in the video is that the EGR Solenoid Activation Valve may be causing the EGR Valve to remain open. If your car continues to stall or idle rough after replacing the EGR Valve, verify that the EGR Valve Actuator Solenoid is operating properly. Also, a large source of a vacuum leak can be from a cracked or leaking Brake Booster. A smoke check for vacuum leaks does not always catch it. Consider replacing it if your brake pedal pressure seems unnormal. I hope this video helps.
Below is a link to a really good Corvette EGR article that explains everything about the EGR including how it works and how to test it etc…
tech.corvettec...
20 окт 2024