3.sloRunner

I just rebuilt the engine changed the fuel filter and checked the pump which works and fuel is getting to the rails cuz the first time I started it ( right after puttin in new fuel filter) it started right up first time. High parked idle, great idle in gear. Well I drove it up and down the road a few time up to 45mph and sometimes it would sound like it turned off for a second then keep on going as if nothing happened. Then when I parked it and turned it off I tried to turn it back on to make sure it was working and now it won't start at all. Just the starter running but the engine won't run. I don't get it cuz it JUST ran fine. My military mechanic buddies say it's a fuel delivery issue but they're not sure exactly what.. Anyone have an idea? Thx

3.sloRunner

33 views with no response. I need help here I'm lost. I'm gonna expirrament with it in an hour or so.

3.sloRunner

Well it looks like it's not even a fuel issue after all lol there a crack in the intake hose going to the Tbody so no vacuum which mean no open flap in the MAF so no fuel pump. That's my hope anyway. I'm gonna do the ISR mod tmrw and see how she runs..

scope103

No, that's not it. The fuel pump runs with the key in start, once it starts it gets a signal from the MAF to keep the Circuit Opening Relay closed. If the MAF failed (through a vacuum leak or otherwise), the truck would start, run a few seconds and quit.

The starter is noisy enough that you probably can't tell if the fuel pump is running while cranking. So connect the FP port in the diagnostic connector to 12v. You should be able to hear the fuel pump running from there. Then try to crank it. If it runs, you most likely have a bad Circuit Opening Relay.

That relay (or any of its wiring) failing might cause the "turned off for a second" that you heard.

The other possibility is the EFI main relay, which is towards 12v from the C.O.R. It would also take out ignition. So you could check for spark as well.

But the easy one to check is the fuel pump.

3.sloRunner

i have already checked the pump and it works. after i found that the flap is run by vacuum i checked my hose and it had a bad crack in it right at the Tbody. ill know fer sure when i do the ISR mod tonight. my buddie who has a built rock crawler and long time toyota guy came back after vacation and he basicly figured it out for me while we were messing with it. who knows tho.. if it doesnt work ill check the relay

3.sloRunner

Well I did the ISR mod and it started several times and seemed fine for about 5-6 starts. Then back to 2-300 rpms then dying.

3.sloRunner

well after letting it idle awhile its running good except now its overheating.. im hoping its just a faulty thermostat but we'll see

andrew1586

You figure this out