Pontiac Grand Prix re-starting problem

pontiac

#1

My 2004 Gran Prix (58,000 miles)occasionally hesitates to re-start after it’s been running. It turns over like normal and tries to but it stops, then when I turn the key again it turns over for a few seconds before starting, and sometimes requires a second re-try before it starts. The dealer hasn’t been able to figure it out because it won’t do it when he has the car. Any suggestions? Thanks!


#2

This is not a problem that requires a dealer. Unless you need warranty or recall service you don’t need to use a dealer. Find a good, local, independent shop and just use them for everything.

If I have understood you correctly you’re saying that the car begins to crank over but then stops cranking over all together. Does it just go silent? Does it go click-click-click? How does it sound before it stops cranking? Slow and tired?

Your issue is likely a simple one. Drive in to any big-box auto parts store and ask them to test your battery and charging system. (How old is that battery?) The other thing that needs to be checked are the cable connections - both ends of positive and negative should be pulled, cleaned and assured tight. If there is any sign of corrosion (and perhaps even if there isn’t) the cables should be checked underneath of the cable insulation.


#3

When it does re-start, does it also run a little rough for a few seconds? If so is possible that the fuel pressure regulator is failing. This is a very common issue with these cars.

The other thing is possible fuel drain back into the tank through the fuel pump check valve.

Keep in mind these are just two of many possiblity’s.


#4

I know the battery is weak (it’s the original, and I have plans to replace it in the next couple weeks before winter sets in), but it doesn’t stop cranking. It’ll turn over as usual, it just won’t always re-start the 1st time I try after it’s been running (it starts just fine when the engine is cold). It could be 5 minutes, 10 minutes, even 60 minutes after I’ve shut it off that it hesitates to re-start on the 1st try. Most times it restarts just fine, though. It may be a fuel-system related thing.


#5

“It turns over like normal and tries to but it stops”

Well, what does “it stops” mean?

If the crank stays healthy then the first place I’d look is at a fuel problem as suggested by barteik below. Try flooring the accelerator and turning the key. If that gets it to fire up then you have a flooding problem, likely either from a leaking fuel pressure regulator or leaky fuel injectors. To learn about the check valve you can get a fuel pressure gauge on it and see what happens to the pressure when you shut the car down. It should mostly hold. If it drops off rapidly then its probably the fuel pump’s check valve.


#6

By “it stops” I mean that the engine starts to run, or at least it sounds like it’s starting to fire up, but then it stops. It doesn’t stop cranking like a weak battery or bad connection would cause. I think you and Barteik are heading me in the right direction; something with the fuel system is amiss, it’s a matter of having the dealer go through the possibilities to sort it out. They haven’t been able to duplicate the problem when I’ve had it there, and either they aren’t aware of there being a common problem with the fuel system, or maybe they don’t want to admit it quite yet!


#7

Do yourself a favor and just find a local, independent mechanic rather than using a dealer. You’ll often get much better service and spend less $$.

Its not that hard to sort out - you just need someone interested in sorting it out. Try the flooring of the gas pedal while you start it. If that doesn’t do anything have someone get a fuel pressure gauge on it.


#8

I’ll give the flooring thing a try. The car is still under warranty, so I might be able to get the dealer to do all this for free. It’s been happening off and on for a couple years, each time I mention it to them they seem to try to figure it out but without success, but maybe now with your and Barteik’s helpful hints I might be able to steer them down the right path. Thanks for all your suggestions!