Start and Stall and Start and Stall?

I have a 94 GMC Jimmy that is kind doing the same thing. I have replaced the fuel pump already and then about a month after that something broke (pipe) in manifold which made me lose half a tank of gas in less than 5 min. Found out that when that pipe was replaced there was 2 quarts of gas in my oil. Now my truck runs perfect for 10 min tops and then stalls out, I can immediately start it back up and run it for 10 min and then the cycle continues.

I recommend you check the fuel pump relay for a intermittent problem first.

ty Cougar, going to write down all the suggestions I get, cuz my mechanic is even stumped

It may be unrelated - do you know this is a fuel problem ?

With these symptoms I’d usually check the coil first to ensure it’s not on its way out, wouldn’t be unusual for a 10+ year old car.

But if it is fuel, I’d start with Cougar’s suggestion though and check the relay first, but if that checks out okay you may want to check the fuel pump again.

If that new fuel pump pumped half a tank of gas in 5 minutes, you may have exceeded it’s functional tolerances and damaged it permanently. I don’t know what the service limit of that fuel pump is but I can guarantee it was never designed for that type of duty.

tyvm for your help, going to give all info to my mechanic, I would like as much info as possible about this problem.

Even if the fuel filter was changed a few months, replace it again. Connect a jumper wire, from a power terminal, straight to the fuel pump wire connector, at the gas tank, to ensure that power (12 volts) isn’t lost during test. Then, mechanic should put a fuel pressure gauge on. Run the engine, in DRIVE, at 1500 rpm, and observe the fuel pressure until the engine stalls. If the fuel pressure falls off, then the engine dies in a few seconds, the fuel pressure regulator should be checked for proper operation. This is a web site which will help a mechanic troubleshoot the fuel pump system: A relay, which is intermittent, can’t be reliably tested because, sometimes, it’s good, sometimes bad, sometimes good, etc. Replace, or swap, the fuel pump relay. On some (all?) Jimmys, the oil pressure switch is wired to cut off the fuel pump if oil pressure drops too low. What if the oil pressure switch were intermittent? Again, since it’s inexpensive, just replace it. {These pages can be printed for your mechanic, can’t they?}.