same problem here. replaced ip, fuel filter numerous times, tried a holley blue w/ regulator, now i have a facet, fixin to bypass the electric pump and go with a new mechanical pump. i have a clear line on the injector return to filter and fuel flows from filter to rail, put clear hose on rear crossover. have plenty of flow on the return side, but doesn't have any pressure at the schreader valve (i have a gauge on it all the time). it seems like all my fuel is going to the little return line traveling away from the filter head. i'm getting aggravated with this. am i on the right track thinking about putting a new mechanical pump back on it? is there a valve in the filter head that i can check? i have hardly any fuel coming out of the return fitting on top of both of the ip's. help dave!

 

my problem is that it runs ok til i get to the end of the driveway, and it acts likes its running out of fuel and stalling. prime it back up with the facet pump (i still don't think i'm getting enough fuel) and limp it back to the garage. i need my truck running again immediately. i'm tired of throwing parts at it. i'm going to put a new mechanical pump on it tomorrow, pull the filter head off of it and take a look at it. maybe plug the injector-to-filter line. i have new rubber fuel line from the tank all the way to the lift pump. i pulled the sender/pickup tube out of the tank and it is only metal line. but it still does it with the tank completely full. i don't think it's the rubber hose collapsing or i wouldn't get lots of flow. i need to figure out why when it comes out of the filter head, fuel goes to the return. like i said i barely get any fuel to the ip. sorry if i am rambling, just trying to cover all the bases to avoid the same questions. i've been reading and searching posts for about a month with no results.

 

almost forgot. i have no front tank, only the rear, and the selector valve is bypassed. the water seperator is also bypassed right now so i can figure out my problem. rubber fuel line runs straight from rear tank to lift pump.

 

There are check valves in both the IP return and filter return.
Sounds like one or both of them is fubar.

 

ok, i put a new mechanical pump on it tonight, took the check valve out of the pump return and the glass ball still moves, if that means anything. started it up and ran it for about 45 minutes til it finally died. i have clear hose on the filter return. fuel is travelling away from the filter. it has a bunch of air in it, then it cleared up. about every 2 or 3 minutes more air would appear and the truck would start running rough, then it would clear up. i still have maybe .5 to 1 psi of fuel pressure. is the check valve in the filter head where the return hose attaches? pulled the filter head off, looked normal to me. if i had a pinhole in the pickup in the tank, wouldn't that make it suck air constantly. i don't under stand how the mech pump, the holley blue pump and the facet pump, could all be bad. so i'm ruling out the fuel pumps. it would either have to be in the pickup, or in the filter head. it was doing this on both ip's. so i'm going to cross the ip off my list.

i put both of my fuel pressure gauges on the fuel line before it gets to the filter, and turned my facet pump on and and bled it and still got no fuel pressure. my only guess from that is, it is sucking air from the tank pickup. maybe i'll play with it again tomorrow. i'll keep yall updated until i find out whats going on.

that cummins and fass pump is starting to look better everyday. maybe go back to a stump puller truck and drop a 300 straight 6 in it.

 

I appreciate not having been dropped off this topic, I'm just back from a 4 months, 14K mile trip to Alaska and back to Baja in my 02 GMC Duramax diesel. In Anchorage the truck finally quit, had starting problems all along, but managed to get there unassisted. Diagnosis, Fuel pressure for starting should be 5K psi and for running not less than 23K psi. Mine were 1K psi and 12,5K psi respectively. Solution: All 8 injectors had to be replaced, still covered under warranty (saved abour $4.5K) and a hell of a 3 day job! I had to pay for a new fuel filter bracket assembly, because in there is a small check valve in tyhe assembly and the plastic ball wears. The valve on it's own (they say) is not acessible. Cost $800 plus $175 for installation (2 bolts and 2 hose connections)! I took this unit with me to pull it apart and see the check valve with my own eyes.
I know this is a little off the topic, but it comes down to this check valve, which I'd also like to see on my 84 Ford truck that still is not running.

Question to Dave: Is there an after market check valve which exists that will do the job and which can be installed separately? Are there any photos available on these check valves. Can they be separately be purchased and replaced?

 

If you have new fuel line running from the tank to the lift pump with everything bypassed, the only place you can be sucking air at is in the tank.

When you say .5 to 1 PSI fuel pressure, where is that reading taken at?

 

thats what i'm thinking. i'm going to try running it off of a 5 gallon can to see how it does. i'll go back out there tomorrow or friday to play with it again. thank you dave.

 

well, got 'er running. put a 100 gallon tank on the back, plumbed it up. got fuel pressure, pump timing is off a little bit (need to fix that tomorrow). the good thing about the tank on the back is that when i shut it off, i don't get any fuel drainback because the tank is higher than the lift pump. i'm either going to put my old injection pump back on, or try and time this one. it's off of an '83 model. seems like the governor isn't as high as on my other pump either. besides, i know where the other pump is supposed to be timed at. (made marks for it.) btw, thank you dave for your suggestions.