96 BUICK regal V6 3.8L stalls

[Jie Pan]

Hello guys,
I have a 96 Buick regal v6 3.8L. It ran good. Started from last winter, it started to act up. In the morning, 98% OF the first attempt to start the car failed: it started but died in a few seconds, but the 2nd attempt always got it start. One month ago, I drove it for 1.5 hours, and parked there for 15 minutes, could not get it started, opened up the hood, waited for 15 minutes, it started. Then I drove it to a auto shop, they replaced the starter. One five days later, I could not started it again after 1.3 hour driving and parked for 20 minutes. Wait for 15 minutes, it started again. The odd is that when it refused to start, the radiator gap is very hard (but not over heated yet), after started it and drove for 30 minutes or so, I feel the gap is cooler than when it would not start.

I drove it back to the shop, they could not any problem. Drove it back. three day later, it stalled when driving. I didn't realize the stall until I need to turn: lost steering and brake power, then notice that the whole dash board doesn't have any light on. Since the car shut it off only after half mile driving, it doesn't looks like heat related (It was on the mountain, it was about 70 F). Then I sent the car to a different shop.

At the shop, they took off the ignition model and tested it good, and put it back. Since then, they started the car several times per
day. Finally, on one day, the car shut itself off after running for 2 hours, and they could not start it. However, they checked and
didn't find any code was set (they said because service engine light was not on). The shop have been trying to start the car several
times per day for 10 days they didn't have another failure. I am not sure what to do with the car. I read posts here, and have the shop
checked short circuit, ground fault, fuel wiring harness, catalytic converter, they didn't find anything, and they said that fuel pump
seems ok.

I plan to replace crank sensor, fuel filter, and fuel regulator sensor and use the car for work commute (2 miles). Can some help me
to offer some suggestions on what should be done on the car (since it is old car with 120K on it, I don't want to spend more than
$500 dollar on it unless I am sure the problem can be fixed). Thank you all to read and offer your help to me. Thank you, THANK
YOU!

[maxwedge]

When the engine stalls if it will not start right away someone has to check for spark and injector pulse, standard diagnostics here.

[Tech II]

From what I have read thus far, find a new garage....

When you say it won't start, is the problem that the engine will crank over, but will not fire, or that it won't crank over at all? If it cranks over but doesn't start, why put a starter in? If it doesn't crank over, then the SECURITY system should be checked, since they put in a new starter.....

There are no codes because the CE light is not on? Did they even scan for code?

When the car wouldn't start for them, that's when it becomes EASY to diagnose....like Max stated, that's when you check for spark, fuel pressure, injector pulse, etc.

how often has the car stalled on you? More with a hot or cold engine? Does it stall more when cruising or coming to a stop? Now when it stalls, it cranks over but doesn't fire? But 15 minutes later, it will? More than likely, a crank sensor, ICM, or fuel pump.....other potential problems are IAC, fuel pressure regulator, MAF.....BUT NONE OF THESE PARTS SHOULD BE CHANGED, unless proper diagnosis leads to one of them....

[Jie Pan]

Originally Posted by maxwedge

When the engine stalls if it will not start right away someone has to check for spark and injector pulse, standard diagnostics here.

Yes. Spark, injector are checked, ok. Thanks.

[Jie Pan]

Originally Posted by Tech II

From what I have read thus far, find a new garage....

When you say it won't start, is the problem that the engine will crank over, but will not fire, or that it won't crank over at all? If it cranks over but doesn't start, why put a starter in? If it doesn't crank over, then the SECURITY system should be checked, since they put in a new starter.....

It cranked but didn't start. This was what I thought, told the mechanics that it didn't look like the starter problem, but he said so. I thought he has more experience, so let him changed the starter. Anyway, what concerns me most is that the car shuts off during driving, then steer and brake are very very heavy if still possible.

There are no codes because the CE light is not on? Did they even scan for code?

The shop said that they did scanned. I also had my friend scanned once, no code was set.

When the car wouldn't start for them, that's when it becomes EASY to diagnose....like Max stated, that's when you check for spark, fuel pressure, injector pulse, etc.

The shop said they checked for these items.

how often has the car stalled on you? More with a hot or cold engine? Does it stall more when cruising or coming to a stop? Now when it stalls, it cranks over but doesn't fire? But 15 minutes later, it will? More than likely, a crank sensor, ICM, or fuel pump.....other potential problems are IAC, fuel pressure regulator, MAF.....BUT NONE OF THESE PARTS SHOULD BE CHANGED, unless proper diagnosis leads to one of them....

Only once when driving. It cranked over but did fire. 15 minutes, it starts normal, and runs smoothly.

Thank you, I will keep all updated.