Mercedes-Benz S320

1995 Mercedes-Benz S320 Ignition System   

Origanlly the engine would start to miss and by turning the car off and on it would stop missing. Now, when you try to accelerate thru to a normal speed, it will miss, but as soon as you back off of the accelerator, it will no longer miss. Have changed sparkplugs, and fuel filter. Fuel pressure tested to over 50 psi. Pressure regulator on fuel rail and air sensor next to airfilter were changed last year. I removed the sparkplug cover to inspect wiring at night, and no spark leaking anywhere.

No leaking from the coils either?

It is possible you have a sensor out of range. Have you had the computer scanned for trouble codes?

No, well yes, I had a mechanic check the pressure and hooked up a tester to a receptacle on the driver side just above the leg area. Claimed a module was shorted out and that he could repair the module without replacement. I became leary and did not go back. I apologize for the incon. but I am between jobs and I do have some mechanical savy.

Sorry, I believe he mentioned the TPS module or sensor.

TPS, throttle position sensor. The only possible repair here would be to wiring to the sensor or its connector. A malfunctioning TPS can cause the stumbling on acceleration (to lean of a fuel mixture).

More than likely, that is what he meant. I have had the scent of gasoline before and the car will backfire at times.

Okay check the connector and wiring near it. As a test, you wiggle the connector/wiring with the engine idling to see it causes a change in how the engine runs. PLEASE USE EXTREME CAUTION AROUND MOVING ENGINE PARTS!