Mechanics

BUICK PARK AVENUE MECHANIC PROBLEM

1995 Buick Park Avenue • 175,000 miles

Engine maintenance on this car has been so-so, not great but not terrible. That said:

First cold day of the year, the car drives the 20 miles to my first stop at work with no problems. Go to start it up from there (after about a 30 minute wait) and it won't start. Had it towed back home and mechanic magically got it to start by resetting the security system, said that it wasn't reading the key right any more and I would just have to reset it from time to time. No biggie, I figure. Drive it to work the next day, it makes it all the way (45 miles) and I park it for the day. Going to leave, it won't start. Reset security system, no start. Start driving wife's car to work. Car sits there for a week. Go to get it with a trailer and the stupid thing starts right up with no problem. Driving home, it seems to lose power and have to keep the pedal pressed about 3/4 of the way to maintain 70 mph.

Over the past 3 weekends, I've had 2 mechanics working on it, replacing everything that they think it could be. Parts replaced:
Fuel pump, fuel injectors and rail, ignition modules, DIM module, upper intake and gasket, crank sensor, a few cracked vacuum elbows.
The symptoms the car is having is that it will start up just fine but immediately start to bog down like it's running way too rich. Pulling the throttle will result in backfires and bogging and ultimately, or a healthy sounding roar from the engine followed by backfires. All starts result in a stall after 30 seconds at the most. ODB2 scanner says "prom error" in history, but with no active codes. Shows no weak cylinders, but I am waiting on a compression test to verify that. They also were convinced it was a bad catalytic converter so they detached the exhaust after the manifold, with no change (except for the volume). With the exhaust off, they said the car was running very rich. If it helps, from my non-mechanic perspective it *really* sounded like a drag racer that was idling really low.

Fuel pressure is good, spark is strong, motor cranks just fine. Will not run. Any ideas?
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Nathanharris
January 21, 2013.



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