91 explorer head gasket issues!

Okay, so I replaced the heads and gaskets on my friend's '91 explorer 4.0 OHV motor. It ran before the job. But now it won't start. Occasionally it acts as if it wants to start, but never fully does. On one occasion it started and idled, albeit roughly, for about five minutes then died, and since then will not run. All spark plugs are brand new, gapped, and in correct sequence, injector connections are on the correct parts of the fuel rail, and the fuel lines are hooked up. It baffles me, but any suggestions would be very much appreciated.

Okay, so I replaced the heads and gaskets on my friend's '91 explorer 4.0 OHV motor. It ran before the job. But now it won't start. Occasionally it acts as if it wants to start, but never fully does. On one occasion it started and idled, albeit roughly, for about five minutes then died, and since then will not run. All spark plugs are brand new, gapped, and in correct sequence, injector connections are on the correct parts of the fuel rail, and the fuel lines are hooked up. It baffles me, but any suggestions would be very much appreciated.

My mom had a 1988 bronco and anytime we had to replace anything on it we had to reset the fuel pump. Hers had a button under the passenger side dash. buy a haynes manual if your truck has one then that might be it. I would use a spark tester and make sure it is getting spark. And unhook the spark plug wires, pull a plug out, turn the car over and see if you can smell gas in the cylinder. DON'T TRY TO SNIFF IT WHILE THE ENGINE IS TURNED OVER!!! Or just check the fuel pressure.

Okay, so I replaced the heads and gaskets on my friend's '91 explorer 4.0 OHV motor. It ran before the job. But now it won't start. Occasionally it acts as if it wants to start, but never fully does. On one occasion it started and idled, albeit roughly, for about five minutes then died, and since then will not run. All spark plugs are brand new, gapped, and in correct sequence, injector connections are on the correct parts of the fuel rail, and the fuel lines are hooked up. It baffles me, but any suggestions would be very much appreciated.


It sounds to me like a timing issue. The first thing I check on an engine if it won't start and I just did major work is the timing. Never worked on a 4.0, so I'm not sure just whats involved on that engine - but it sounds just like getting the distributor timing a notch off on an older engine.