Hello guys,

a couple of month ago I posted here to have help with my car problem, since that I checked everything you guys said and I have a bit more of developpement:


Here is the probleme on my 2.3-16v 190e 1987:

- Unburned fuel smell at the exhaust, it is worst when I press the gaz pedal!

-Very low mileage : 13mpg

-low performance

-When the car is cold (30C) and I press hard on the gaz pedal, The engine is loosing alot of power and I here Puff-Puff-Puff-Puff inside the engine bay and that until I release the gaz pedal.

-Low acceleration at higher speed (80km/h +)


I've checked almost everything:
-fuel mixture is great: O2 reading are PERFECT (the O2 sensor is new), a scope reading on the ignition is also perfect(correct burn time and voltage), AND the sparkplug tips are also perfect( nice brown). So I beleive the problem isnt in the mixture.

-Ignition timming is great and ignition voltage to (scope).

-Valve timming and valve clearance is perfect.

-No exhaust leak.

-SUmmary: injection and ignition seems to be fine, but there is still alot of unburned fuel passing to my exhaust system...!!

Hypothesis: there is a part of unburned fuel that doesnt expode in the cylinder OR the explosion in the cylinder is too long and the extra fuel just goes in the exhaust: where I smell it.

-Also: the engine had been rebuild 10K km ago, but I think only the head had been done.


What could be the problem??

Thanks!