Car will die when the RPMs go below 1500

rpm
mercedes-benz
e-class

#1

I have an issue with 1995 E320 Mercedes. The car will start, it does not idle so I must keep the RPMs above 2000 and it runs fine. If the RPMs fall below 1500 the car will abruptly stop and the motor will die. I have changed the fuel filter and fuel pump pressure is normal. PLEASE HELP!


#2

You probably have either a fairly large vacuum leak or a bad idle air control (IAC) valve (though I confess uncertainty about whether this car has an IAC.

Pop the hood and look for a detached, split or broken vacuum line (some are really big like the brake booster line; others are very small - there should be a vacuum schematic on the underside of the hood). Also carefully inspect the intake tract - the really big black tube that runs from the air filter to the throttle body.


#3

Thanks I will do that tonight and let you know.


#4

After checking for cracks in the air inlet tubing and for big vacuum leaks, get some aerosol cleaner from the auto parts store and clean the throttle body and the idle air control valve. Hope that the idle air control has not failed, because that is a $400 part on this car.


#5

These engines didn’t have an IAC valve. It was done with the throttle valve motor/actuator.
Sounds like a huge vacuum leak,throttle plate down, a problem w/wiring @ actuator or the mass air flow sensor

Is the ASR light on?

I drive a 94 wagon and spent 28 years w/ Benz at dealership level, but now my retired butt is loosing its memory.
Hope it is resolved by now; I just found this w/site.