Mechanics

MY , SUDDENLY DIES WITHOUT WARNING AND WILL NOT RESTART.

2006 Pontiac Grand Prix • 70,000 miles

I have a 2006 pontiac grand prix. In January 2011 while driving it suddenly died no warning no sputtering just dead. When I tried to restart the starter would turn but the engine would not fire. I had it towed to shop where the next AM it started fine. Car ran fine after, with no problem until late August when again the same thing happened. Once again had tow truck on the way when after about an hour decided to try one more time and it started fine. Took it to GM dealer, had no codes and could not duplicate the problem. Dealer suggest possibly replacing the fuel pump at a cost of $850. But opted not to do that. Now its October 11, 2011 and it has happened again! Any Ideas?
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Jkopontiac
October 12, 2011.




What I need you to do is this. When it doesn't start, you need to check if the engine is getting spark and fuel. There are detailed directions on our homepage under the DIY section.

As far as the fuel pump, usually the engine will spudder and you'll notice a loss of power when it goes. A crank shaft sensor will shut spark to the engine. It would be like turning the key off.

Check what I suggested and let me know what you find.

After the first incident in January the mechanic did check the fuel pressure and spark, both were fine. I have seen several articles about crankshaft sensors and it sounds like that could possibly be the problem but all 3 incidents have happened after car has been parked for 8 hours or more and occurred within 3 miles of driving. Any other ideas?

Tiny
Jkopontiac
Oct 12, 2011.
That is why we need to check for spark and fuel when it won't start. If the crank sensor is bad, there won't be spark to the engine. Actually, that was my first guess based on your description. As far as the sensor, they all act differently. Once we determine which is missing, we will know what circuit to focus on. Otherwise, we may be replacing good parts.

Check this Morning It does have spark. Can hear fuel pump when switch is turned on but sounds weak.

Tiny
Jkopontiac
Oct 12, 2011.
If you have spark, then chances are the pump is the issue. To confirm, you need to check fuel pump pressure.

Had the car towed to the shop yesterday. They checked the fuels pressure and it was fine, checked the spark also fine. Only thing they seemed to find was the battery had a bad cell hadn't had any problem with this before and the battery is only 1.5 years old. Mechanic says cant find anything else and its now running fine. Don't know what to do with it at this point!

Tiny
Jkopontiac
Oct 13, 2011.
Update, finally had crankshaft position sensor and oil pressure switched replaced in Mid October. Car has been running fine since then, until yesterday when it stalled within one mile of leaving home and again wouldn't restart until several hours later. Exact same symptoms as before! Does anyone have any suggestions?
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Tiny
Jkopontiac
Dec 27, 2011.
If it won't start, my guess is there is a loss of fuel or spark to the engine. If you have both, it should run unless there is a timing issue or compression issue.


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