92? engine in 94 GP LE -- running problems

[Prof BruJoe]

Hi. I had a differnet engine dropped in my 94 GP LE (was a 3.1 MPFI) and the engine in now is apparently a '92 3.1 MPFI.

The engine was replaced last summer (Blown heads), and it developed stalling problems soon after I got it back. It started stalling and not startoing back up for several hours. When it got cold in the winter, it just ran rough but didn't stall and stay off. Now, as I have gotten back to it this summer, I changed the following: CKS, plugs, wires, fuel, air and PCV filters, oil and oil filter.

It starts, runs better, but after 20 minutes is stalls and won't start for several hours. There is spark going to the engine, and it seems to be trying yo start while it is turning over.

Has anyone had this issue with their engine? Could it be a fuel system issue, and is it difficult to change?

Thanks,

Bruce

[GTP Dad]

Check the fuel pressure at the fuel rail. This sounds like a fuel pressure regulator problem. If the regulator is bad then it will not hold pressure and cause the car not to run or stall. The other possibility is the fuel pump but the pressure check should tell you if it is good. Should be 45 pounds at idle or more.