2000 Saturn intermittent fuel flow problem?

2000 Saturn Wagon SW2, car has 170K on it, engine replaced at 50k so a little newer, stick, basic model (no cruise etc). Car is new to me but used. Prepurchase inspection by 2 different mechanics turned up a similar list of small problems but nothing with the fuel system.

Problem seems to be in the fuel system somewhere. Car will be running fine, then simply loose power like the fuel was cut off. Taking it out of gear doesn't do anything nor does switching gears. Happens at both low and high speeds, but ONLY after the car has been running for a good hour plus. When cold or just local driving seems fine. Symptoms are a complete loss of engine power and then dash lights for oil, fuel, and check engine come on as the car finally stalls out completely. Turning off and immediately back on seems to clear the problem sometimes, sometimes it continues and dies again. I have on one occasion heard a thumping noise from the back of the car while this was happening (possibly the sending unit on the gas tank?).

Have taken it to mechanic but they can't (or aren't interested enough) find the problem. Tried dry gas thinking it might be water in the tank, still does it after cycling a full tank of fuel through it.

Hopefully this is a common enough problem that someone will recognize something.

Thanks Jeff

Hmmm. A reboot causes it to run again. Must be another fine product from Bill Gates...

Have you read out any fault codes or done a fuel pressure test? When was the last time the fuel filter was changed? Fuel pressure should be monitored under your failure conditions. There is usually a test port where a pressure gauge can be screwed on (similar to A/C service port). Actually I needed to measure fuel pressure on my Lw300 and found that an old R22 type A/C manifold gauge just fits. Not likely to use R22 anymore so wtf...

I never observed the fuel indicator come on when engine stalls, curious. All the indicator lights come on at key-on as part of a lamp test. Could you have an intermittent power feed?

Why was the engine replaced? What led to the engine replacement?

Oppie