Intermittent starting problems

2001 Chrysler Sebring Sedan LX, automatic 4-speed, 2.7 L V6 SFI (DOCH)

First there was transient illumination of Check Engine light in March 2010 that disappeared after two days of driving. Ever since an oil change and repair service for an A/C leak it has been intermittently hard to start, i.e. engine cranks with full force but doesn’t start up. Sometimes pressing the gas pedal a few times before cranking can help to start the engine. I noticed that the engine oil was also overfilled by about 1/2 inch that I initially ignored although it says on the dipstick DO NOT OVERFILL. The repair shop says there is no connection between oil overfill and the starting problems. Since then they have diagnosed it as a problem in the fuel pump so they changed R&R Relay in April after which the same problem still existed. Then they felt the problem was internally in the power control module which they replaced in May at which time they also drained the extra oil. Even this didn’t fix the problem. When the engine acted up again in one morning they came over and attached the diagnostic computer leads which eliminated the clitch so the engine started up again. Incidentally, the problem appears to occur more when the front of the car is tilted downwards. At this time the service shop is still diagnosing the problem, and they don’t seem to know what’s wrong. Is it time to buy a new car or should we pursue this further and get a second opinion?