I have a 1991 Cadillac Deville with a V8. It won't pass smog. Has high co. I replaced the egr valve, charcoal canister, spark plugs, spark plug wires, cap and rotor, catalytic converter, oxygen sen
Cars & Trucks - Cadillac - DeVille - 1991 Cadillac DeVille
Answers & Comments
Hello! when you say you checked the MAP sensor what do you mean? Did you take voltage readings at idle ? A vacuum leak is the likely culprit, especially to the MAP...The minor shake at idle being the major clue...Send a comment...guru..saailer
I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867
Hello! At idle it must read over 2 volts...as you increase the rpm's voltage must rise to 4 volts...This is at the sensor output...If OK, the engine is running rich and the fuel pressure regulator is suspect...however you do not mention any trouble codes...your car is OBDI and can not be scanned...under the steering column is a connector that requires its two pins to be shorted w/ a paper clip...Then turn on the key (do not start) and the dash trouble light will flash a code...ie...4 long blinks...pause...1 short blink=code 41...send a comment...saailer
Hello! I still believe there is a vacuum leak... Connect a vacuum gauge to the source side of the EGR solenoid... Start the engine, manifold vacuum should be present... If it is not, repair leaks or obstruction between the EGR solenoid and throttle body...
Connect a vacuum gauge to the EGR valve vacuum supply. There should be no vacuum with the engine idling...
With the gauge hooked to the EGR valve vacuum supply, disconnect the EGR solenoid connector. There should be more than 8 inches of vacuum available. If not, repair leak or obstruction in EGR valve vacuum hose.
Is the check engine light on with an a.i.r. code E?...saailer