sheaver76

Hey all-

New to the forum so please go easy on me. I have an 88' p/u that I inherited with an overheat/warped head issue. Decided to rebuild the motor rather than just swap the head since I had to replace the clutch and take everything that far down anyway... Anyway, long story short, she starts and runs great... for about 2-3 minutes then slowly starts losing RPM and eventually dies. Fuel pressure is 38lbs at idle (checked at the Cold Start injector), and about 46 if I pull the vac line. I have noid light pulse at all 4 cylinders. All new components in the Distributor, timing set right per Chilton manual. Cold start injector firing correctly as well. Also, after she warms up a little, I can even start her w/o the cold start injector and get the same results. Additionally, it will start right back up and run again after it dies (which I thought was wierd as well)... I also swapped ECU and AFM from a known working 22RE and still got the same results... What else should I be looking at??? No clue where to go from here... I would really like to get this thing running as opposed to parting it out....

Please help if possible!

Thanks

coryc85

Welcome to YT, sounds like you've done some good troubleshooting. One potential thing is debris in the fuel tank getting stuck to the sock in there...too bad it's a pick up and not a 4Runner, it would be easy on a 4Runner to pull the fuel pump out of the tank and clean the sock off.

scope103

... or clogged fuel filter.

Does the fuel pressure remain constant right up until it dies? (If it does, that points away from the fuel pump/fuel filter system.) Does the timing stay at the right place until it dies? Do you get any codes? Have you tried pulling the plugs? (A wet plug suggests an ignition issue.)

The injectors have a tiny filter at the entry point. A clogged injector could get "worse" over 2-3 minutes as the debris gets packed. I would expect that to affect only 1 cylinder, though.

(The cold start injector only sprays during cranking; it doesn't sound like it has anything to do with your problem.)

sheaver76

Fuel pressure stays @ 38lbs even after the motor dies, so I don't think it is a pump issue (unless it's a "volume" related issue). I haven't pulled a plug yet, but I don't suspect any issues with ignition because of how easily it starts and how well it runs, at least until it dies... I will go pull them though just to be sure...

Thanks, I appreciate the suggestions as I have no idea what else to look at.

scope103

Codes?

If your ECU is not receiving IGF from the igniter it will shut off the injectors. It should throw code 14, and it should happen faster than 2-3 minutes (should be about 8 ignition cycles). But if you have an intermittent IGF ...