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2008 Turns over but wont start!!

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DMACKD

New member
Hello everyone I'm new to Grand Prix forum. I have a question about my 2008 Pontiac Grand Prix v6 with 40,000 miles. My GP quit on me one day while driving down the road. When the engine died it acted as if I was running out of gas and it gradually lost power. After I tried to crank it, It turns over but wont start. It acts like the engine is starving for gas. Sometimes it will almost crank but then shut right off. When I turn the key to the acc position I can hear the Fuel pump coming on. I am totally baffled by this problem because no check engine light ever came on. Does anyone have any idea what could be the problem with this Grand Prix:th_lipssealed1:

!!!!UPDATE: Took my car to have it diagnosed and it has been determined that my PCM needs to be reflashed. I have no idea what that means and the mechanic doesn't know why it happened. He said the fuel injectors are not getting fuel to them and its because the PCM is not working properly. He also told me that only the dealership can reflash the PCM. Does this sound legitimate???
 
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try starting it with starting fluid. If it starts it's likely the fuel pump. If it doesn't then it's a spark issue.
 
dsmuts said:
try starting it with starting fluid. If it starts it's likely the fuel pump. If it doesn't then it's a spark issue.
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Ok thanks. If it is the fuel pump, why in the world would it be going out so soon. The car only has 40000 miles on it..
 
Yea that's true. I guess over the years of owning so many vehicles I never ran across major problems out of the cars I had until they got up into the high mileage range like 80 to 100,000 miles. But those cars were mainly 90's to 2000 models. I guess they dont make parts as good as they used too esp when everything is being made in china.
 


Ok thanks. When i put a gauge on the rail I'm assuming i am checking for fuel pressure readings. But what should I be reading. And by the way, have you ever heard of fuel pumps going bad in cars with only 40,000 miles? Seems a bit premature in my opinion
 
DMACKD said:
have you ever heard of fuel pumps going bad in cars with only 40,000 miles? Seems a bit premature in my opinion
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Heat damages them. They're cooled by the gasoline. When the gas gets low enough, it doesn't coat the pump, and it gets hotter and hotter. If it's been run severely low many times, it could burn out prematurely. Additionally, it's always possible to get a defective part.

But I don't think the pump itself is your issue. You hear it priming. So check the pressure at the rails.
No harm in playing with the maf, but I'd be faster to blame the throttlebody if I thought it was starving for air. Actually, just poke the plate to make sure it's not stuck closed.

Ignition on, engine off: 384-425 kPa (56-62 psi), should drop no less than 34 kPa (5 psi) when the pump turns off.
 
Yea I've been told by several mechanics that fuel pumps are going bad in cars much faster now than they used too because of the ethanol in the gas. They said that the ethanol gunks up around the pump and inside of your gas tank causing the pump to overheat and burn out prematurely. This very well may be my problem because I havent been using gas treatment in my grand prix simply because I didnt think I needed too with such low mileage. I bought my GP in 09 with only 10,000 miles on it. It was practically brand new..
 


OP make sure to make a small donation to site, if the members here are able to help you out with your vehicle, keeps the site and information alive!
 
Hey bro, if u unplug your MAF and starts that is your issue, if not check your coils and anything that gives you spark but for what you mention sounds like the MAF
 
You know, I was just thinking... this could also be a fuse issue. For example, the fuse for the injectors could be burned out... if you've got fuel pressure, air, and spark, that's worth looking into.
 


DMACKD said:
Hello everyone I'm new to Grand Prix forum. I have a question about my 2008 Pontiac Grand Prix v6 with 40,000 miles. My GP quit on me one day while driving down the road. When the engine died it acted as if I was running out of gas and it gradually lost power. After I tried to crank it, It turns over but wont start. It acts like the engine is starving for gas. Sometimes it will almost crank but then shut right off. When I turn the key to the acc position I can hear the Fuel pump coming on. I am totally baffled by this problem because no check engine light ever came on. Does anyone have any idea what could be the problem with this Grand Prix:th_lipssealed1:
Click to expand...
Ok guys here's an update on my problem. It has been determined so far by my mechanic that the fuel pump is bad even though it still primes when the key is turned. He came to this conclusion after he poured gas in the throttle body and the car cranked and ran for a few seconds. He said that even though the pump still comes on, it still is not putting out enough fuel pressure to sufficiently crank the car. Does this sound like an accurate diagnosis to you guys??
 
Unplugged the MAf sensor problem still there. checked the coil and it tested good, had plenty of fire.
It has been determined so far by my mechanic that the fuel pump is bad even though it still primes when the key is turned. He came to this conclusion after he poured gas in the throttle body and the car cranked and ran for a few seconds. He said that even though the pump still comes on, it still is not putting out enough fuel pressure to sufficiently crank the car. Does this sound like an accurate diagnosis to you guys??
 
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