94 E320 Hard Starting
 

My 1994 E320 has a hard starting issue. I have had it to a mechanic who at the time said he could not diagnose the problem until the main wiring harness was replaced (was there a recall on this?) Anyway, he rebuilt my fuel pump because the line pressure was not up to spec. He then kept the car overnight with a gauge on the fuel line and said the pressure dropped overnight. At the time I didn't have the $750 to replace the wiring harness and have just recently had it done. The problem still persists, and I'd like to avoid another costly repair as the car has 138,000 miles on it. FYI, I already replaced the Overvolt Protection Relay.

BTW, The car starts after 5-10 sec with my foot on the gas. After a few revs it settles in at about 600Rpm idle. It stalls intermittenly if I run the A/C in stop and go traffic or at idle in drive.

Any ideas on what to look at?

Three big issues on these to check.
1. Fuel pressure regulator.
2. Throttle actuator.
3. Fuel injectors.

Your tech should look at these as well as other issues.

Definitly have your Fuel accumulator checked. That could be the cause of hard starting and lose of fuel presure. Its located between the rear axle and the gas tank. If you take the little rubber hose off and it spills gas then you have a bad accumulator. Good luck with your MB...

-Biggs

For the time being to avoid all these checks.
Everytime you start your car. Turn your ignition switch to ignition. Wait for about 5 to 10 seconds to build up fuel pressure. Then crank your engine. Don't press on the gas pedal. Boom your car starts. I have this problem with my 94E320. If your are not in a hurry to leave you can live with it for now.:)

Looks like the throttle Acuator
 

Mechanic says this is the problem and of course the most expensive. Part alone is $900. Argghhh.

First and last Mercedes experience. Going back to my reliable and much less expensive to maintain BMW;)