On hot days, after my daughter’s 2004 Neon has been parked for the day (9 hours or so, usually at work). Starter turns over, and car will not start running. If she lets it sit for a while (2 to 15 minutes, the time varies from day to day) it starts fine. If you goose the throttle, you can get it to run roughly (like missing on a couple of cylinders, or running lean), but you cannot leave off the throttle or it dies. Never acts up in the morning. Doesn’t seem to matter if the tank is full or low. Rarely happens unless the outdoor temperature is hot and the car has sat long enough to cool down. I left it with a dealer for 2 weeks and they could not duplicate the problem. Suggestions anyone?
-Thanks
Unless you know how to do a fuel pressure test to check for a weak fuel pump take the vehicle to a reputable independent shop for a proper diagnosis.
Here’s an easy test to see (hear) if the pump is priming the system upon an attempted start.
Remove the gas cap, have a helper turn the key to the RUN position while you listen at the filler pipe for a few seconds of buzzing from the pump.
Not much point doing a fuel pressure test if the pump doesn’t even prime properly.