under acceleration check engine light comes on and smoke out the rear

[justin10morrissey]

when car is warmed up under acceleration my auto 85 makes a loud hissing type noise but i dont think its vacuum and some smoke comes out the rear car was checked for codes and i think it was 42 that came up not sure what the problem is doesnt happen until the car is warmed up

 

[boomdriver]

what kind of smoke?

42 is elect ing system...
misfire when hot thats sending unburnt fuel to the exit...

 

[justin10morrissey]

what kind of smoke?

42 is elect ing system...
misfire when hot thats sending unburnt fuel to the exit...

just a small puff its not very dark and i think it is unburnt fuel

 

[justin10morrissey]

any ideas?

 

[WhalePirot]

By hot, do you mean closed loop? Open loop (cold) will mask many things, plus some cracks may only manifest themselves as warm parts expand, including electrical arcing. If you can find no obvious carbon traces, say inside the distributor cap and the plugs wires are in good condition, you may want to check the color of each spark plug to isolate the cylinder(s).

Though unrelated to the valuable Code 42: vacuum leak? The ECM will try to counter a low vacuum condition with more fuel, hence blackish smoke. If you can duplicate it while stopped, I'd listen carefully for the location, then use carb cleaner spray to isolate it. Particularly, check hoses, fittings and gaskets.

 

[justin10morrissey]

By hot, do you mean closed loop? Open loop (cold) will mask many things, plus some cracks may only manifest themselves as warm parts expand, including electrical arcing. If you can find no obvious carbon traces, say inside the distributor cap and the plugs wires are in good condition, you may want to check the color of each spark plug to isolate the cylinder(s).

Though unrelated to the valuable Code 42: vacuum leak? The ECM will try to counter a low vacuum condition with more fuel, hence blackish smoke. If you can duplicate it while stopped, I'd listen carefully for the location, then use carb cleaner spray to isolate it. Particularly, check hoses, fittings and gaskets.

im not sure its goin to the mechanic who rebuilt it next week cuz i have a warranty on it