My wifes 2003 Monte Carlo has a intermitent starting problem when it’s hot. It runs fine but when it gets hot and you shut it off for a couple of minutes it sometimes won’t restart. It will crank and fire but then runs rough for a couple of seconds then quits. If you wait a little while it will start and run fine.
It’s not throwing any codes. The dealer says it needs a fuel pump & filter which they want almost $1000 for. I hate to spend this kind of money unless I’m sure that’s what it is.
The dealer says ?
Dealers are no better (or worse) than independent mechanics for almost anything you might need done on your car. They will almost always charge more per hour and often more for parts and supplies. They also tend to look at repairs a little different than the independent.
A dealer may well recommend work that strictly may not be needed, but could be connected to the problem or maybe replace a part when a little repair would fix it ALMOST as good a new.
There is no need to bring your car to the dealer for any service other than service that is going to be paid for by a recall or original warrantee. During the warranty period be sure to have all required (as listed in the owner's manual) maintenance done and to document all maintenance work.
I suggest that most people would be better off finding a good independent (Not working for a chain) mechanic.
Is there ever a smell of fuel when this happens? As if the engine might be flooded? If so then you may have an injector or fuel pressure regulator leaking fuel into the intake when you shut the engine down causing it to be flooded. The next time this happens flooring the accelerator while turning the key may get it running (you let off when the car fires). This doesn’t point to a fuel pump.
That problem would be too much fuel. Another might be too little fuel from a leaking check valve in the fuel pump. This would allow all of the fuel to run back to the tank when you shut it off. The car would then run poorly or not at all until the fuel line was refilled w/ fuel & at proper pressure. You could try cycling the key on and off several times, stopping before it cranks and listening for the hum of the fuel pump. If that helps then you might be looking at a new pump.
As Mr. Meehan mentioned a whole different non-dealer, independent mechanic would be helpful.
Just a thought. Could you have a bad coolant temp sensor. That might flood the engine with a cold start mix. When your engine is cold thats fine. When warm it is too much fuel. Most likely you have a combination of issues. What was the last tune up on this car? Have you tried fuel injector cleaner? It could be a bad sensor and poor spark.