I have a 1997 Bonneville SE that has 215,000 + miles and the only things that have been replaced are the coils, spark plugs, starter, O2 sensor in exhaust manifold, belts and radiator hoses. Everything else is original.

Here is what happens;

Car starts right up every morning and idles just fine, Once the car warms up 10 minutes or so if I take my foot off the gas and let it idle it will stall, and then will not restart for about 1/2 an hour, but I can drive anywhere as long as I don't let it idle. I drove from New Hampshire to Connecticut (135 miles) and it ran fine but when I needed to stop at a light or stop sign I would shift to neutral and keep the engine around 1200 RPMs. Then shift back into drive and continue, again I could drive like this all day long.

I am giving this car to my sister and I would really like to fix the problem if possible before she starts driving it.

Any help would be greatly appreciated.

Thank You in advance,

Check on the engine coolant temp sensor.

Thanks for the quick reply,

I just tested the Coolant Temp sensor with an OHM Meter and it was around 2000 ohms cold and dropped steady as the car warmed up. seems to be working correctly, The plug is tight and all of the wiring is good. Also the car has no trouble codes.

Any other possibilities?

Thanks again

You mention driving to CT. Is the car still in CT? If so, where in CT. I'm in CT and could take a look at it.

Thank you for the quick reply,

Yes the car is at my house in Griswold, CT. Exit 85 off of 395. It is about an hour from Enfield.

But before you consider coming here, Are there any other possibilities that I can test / check first?
I was going to go buy a fuel pressure tester as I was not sure if the fuel pump worked differently under a load as opposed to at idle.

So I bought a Fuel Pressure Tester and hooked it up, I am getting 20 PSI when I turn the key on. After I start the engine it is 38 PSI. Can anyone tell me if this is within spec for this car? It still has the original fuel pump and regulator with over 215,000 miles.

Thanks in advance.

Should be in the mid 40s. How old is the filter?

I honestly believe that it is the original as I have owned this car since new and don't remember having it changed.

Change the filter, it'* like $10 and take a half hour. https://www.gmforum.com/t279787/

I'm impressed. Over here in New Britain, CT, I rust through fuel filters if I leave them on for too long. That yours has apparently lasted 215,000 miles sounds strange indeed. (Valvoline will usually swap them out so fast you won't even notice anything but the extra $50 on your oil change.)

Replace the filter, and if nothing changes, check the rest of your fuel delivery system -- in a car with that many miles, the pump and injectors spring to mind first.