Truck Cranks But Won't Start
 

Ok got the death code a while back, truck finally died, would not start on its own just crank and crank, towed it 1/8 mile fired up ran fine, sat for an hour, back to crank and crank. Got a good used vp with 15 K on it, changed pump, still same issues, crank and crank, tow it fires up runs even better than before, sits for an hour just crank and crank, any ideas. i have some codes, and still the death code but i never cleared before new pump install.

1693
1689
0122
0234
0216

is the pump staying primed???

not sure,how can i check, i have good FP at pump, and i have fuel at the injectors when cranking, but if i tow it will fire right up.

I would double check all fittings, sounds like the pump is bleeding down and not staying primed.

Ok when it did this the first time there was no warning thats why i thought it was the pump, changed pump still does it, i checked all fittings when new pump went in today, primed it to the injectors but no start, towed it maybe 50 ft started right up, sat for 45 mins , just crank and crank, gonna do APPS reset(the right way) in am to see if it is the problem. DD

The *first* thing you need to do is clear the codes. Get rid of the old crap and see what is the *current* problem.

That said, and the new pump didn't fix the original problem plus you already checked the connections, etc., the problem may be elsewhere.

Your fuel pressure measures pressure. But it *can't* tell you what is in the line; i.e. compressed air at 20 psi is going to read the same as compressed fuel at 20 psi. If you have a cracked fuel line or bad fitting anywhere between the fuel tank and the lift pump, it could be sucking air and pumping foamy fuel. Not good!

Hopefully you already changed the fuel filter when you changed the I.P., right?

FWIW, I think the fact that it started after you towed it 50' is not a factor. Just coincedence. But if you towed it to a location that changed the truck's attitude (facing uphill, downhill, or level) that *may* be a factor, especially if the fuel level in the tank is low.

Any update on this? Did you get it running man?

Mine did that a while back, turned out to be a bad fuse block, sometimes it would crank, sometimes not, would just die in traffic also...........GM replaced the fuse block and all was good.

It's a long shot here but I'm wondering about crusties in the tank cloggin up the pickup screen. When you pull start the truck you are sloshing the fuel around with no pressure pulling into the pick up whichcould open the screen up and then while it runs it clogs back up agan. With the lift pump and Injector pump both pullin it could pull through this crust but while trying to start it, just the LP alone might not be strong enough.

Your signature doesn't give much of a clue as to what you have on the truck so it's kinda hard to give any good guesses. But one way or another I am guessing that the LP is to weak to get a good supply of fuel through for startup. Be it because of a weak pump, clogged lines or air leak between the pick up tube and the LP someplace.

ttt
Inquiring minds want to know!

:pca1: