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?