Engine Quits After 30-45 Minutes

**DanGale** · 03-15-2009

Hi,
I have a 1997 Grand Prix GTP 3.8L
Recently My Car Will idle and/or drive for about 30-45 minutes then the tachometer drops to 0 the car will still drive for about 5-10 minutes then it dies.
I cannot restart it immediatley. The first time this happened i tried disconnecting the battery cables and it seemed to reset itself and would start again in about 5 minutes.
But now a week later it takes 30 minutes to sometimes 4 hours before it will start up again.

I have done the following:

Changed Plugs And Wires. I use Erodium Plugs And Wires From Pontiac.
The wires are not crossed.

I have purchased a new battery thinking the battery may have something to do with it as it was weak.

I took it to the pontiac dealership on Friday 3/13/09 and paid them 125.00 for a diagnostic test. They said the #3 Cyl is misfiring.
And they cannot go any further with the test.
What a rip off.

I thought maybe a friends 4 year old may have put something in my gas tank as I have dealt with this in the past with a 1967 Camaro and found a smooshed ping pong ball in the gas tank and everytime I gave it gas the car would fall on its face and die as it was being starved of fuel.

This is not the case.

I was wondering if anyone knows how to fix this issue. Before I start dumping money into fuel Pump, Fuel Filter and a new brain as they are a expensive fix.

This sucks as I live 45 min from my job and I end up parking 4 blocks away as the car dies.

Any Ideas Would Be Great.

Thanks