Ok so I just got done putting a 5 speed in my truck ( I think has nothing to do with the problem but.....). I bought the truck and it had an electric fuel pump feeding the factory lift pump but the electric one wasnt hooked up. Well one day i hooked it up and ran it and then a few days later if it wasnt on the truck would spit and spudder like it wasnt getting enough fuel but I would flip the electric on and it would clear up. Well I just got done with my 5 speed and took it on the rd without the electric pump running and it spit and sputtered then died , well I hooked up the pump and went down the rd but then it happened agian with the pump on and died. So i put a new lift pump on it and got it to idle for about 10 seconds then it will die. So now I cant get it to stay running without being in the throttle.

Ive cracked the injectors open to bleed some air but it still hasnt changed. Is my injection pump bad? help please.

Thanks, Adam

 

I would try bypassing the electric pump altogether and see what it does. Do you have a fuel pressure gauge you can throw on it?

 

No I dont have a guage but I can crack all the injectors loose and some bubble will come out and will idle for a little bit but then back to spittin sputterin.

 

If you bleed it, then it runs for a time and dies again, its getting air in the system somewhere. Probably sucking it in between the tank and the electric pump somewhere. Look at all the fittings for leaks or loose connection. Being that it worked before, it may have just developed a leak and then the electric pump wont help at all. Lift pumps don't pump air too well, electric or mechanical.

 

^^^i agree

 

The mechanical lift pump is having trouble pulling fuel through the (turned off) electric pump. This is why I don't recommend pusher pump setups...

 

Ok well I bypassed the electric pump and it still hasnt changed, gonna try a fuel filter?

and does the throttle positioning sensor have anything to do with the motor?

My buddy thinks it might be an issue because my truck was an auto...

 

no the TPS has no effect on the motor.

 

Ok well so far ive put a new lift pump on, fuel filter, and bled the injectors idk how many time and still the same results. Is there supposed to be an o-ring on the plastic fuel line that goes to the lift pump?

And I cant find on air leak, theres no fuel leaking so im lost

 

There may be a leak in the fuel pickup in the tank. How much fuel is in the truck, how much of the fuel sending unit is under the level of the fuel in the tank? There is always the bucket test. Disconnect a line somewhere and stick the end in a bucket of fuel. Maybe where the electric fuel pump was would be a good spot to break it open without taking it all apart. If it runs good from the bucket, the problem is further back, it its still bad, its forward of the bucket. May narrow it down some. It is hard to see leaks on the vacuum side, fuel doesn't leak out, air is leaking in. I don't think there is an oring in the fitting, but I have never really looked that close. Good luck!

 

It says ive a full tank and it always been right.

 

Any other input would be very heplful, im stuck in TN and need to get home.

 

I think there is an oring, still sounds like you are sucking air to me also. If you have an air compressor you can do the old pressurizing of the fuel tank and see if there is a leak somewhere. How was the electric pump plumbed in the fuel system? Is there all new rubber hose ran from the tank to the pump?

 

The electric pump isnt on anymore so its so longer a factor. But it just had a rubber hose comin from the tank , through the pump then to the plastic fuel line to the lift pump.

 

Then I think you leak will be where the plastic line is connected to the rubber one. I don't see how those two peices of pipe could be put together and not suck some air. Go down and get a long peice of 3/8" rubber fuel rated hose and put a new one in from the tank to the lift pump on the side of your engine.
Justin