85irocinjected

I custom wired the engine harness on my 2000 4.8 (which is exactly like 5.3) gave all sensors 12v etc.. Also I used my hptuners and set VATS to NONE. When I try to start the engine it does not get any fuel. When I dump fuel into the intake it will run for a few seconds till the fuel in intake is gone. Someone please help me. Is there something Im missing to turn off VATS besides just setting it to none? My fuel pump is rated to 90psi so that is not a problem.

themachasy

iTrader: (5)

Is your fuel pump relay powered and is the pump turning on? Return or returnless?

85irocinjected

It has the truck style intake so it has the feed and return lines coming from the manifold and both are hooked up properly. The pump is hooked directly to a fused switch so I can turn it on and off when needed. But everything is getting power. Im thinking of just re-enabling VATS in the PCM and using the bypass box I made for an older project of mine before I got hptuners.

85irocinjected

Ok nevermind on the bypass box, found out it will not work due to the truck PCMs having a serial VATS. Maybe if I change the value to the other option besided serial or none it will work? Also I did not turn off the codes P1626 P1630 P1631 yet or change the error mode to no error reported, could that be my problem even though VATS is set to none?

69LT1Bird

iTrader: (1)

You didn't answer the question, does your fuel pump run? does it prime the rail? Do you have pressure at the rail? It doesn't matter what it is rated at, if its not getting to the rail at about 58PSI it won't work.

If you have the VATS off on HP Tuners that is all you need to do.

What do you mean you put 12 volts to all of the sensors? Most do not use 12 volts.

85irocinjected

By 12v to all the sensors I mean the inj. and the other sensors that require a 12v source. I have built many custom wiring harness for these motors but all have been based off the fbody harness. I did not put 12 volt to sensors that dont need it (i.e. powered from pcm) The fuel pump does run and sends fuel to the rails (I was using the port on the rails to drain fuel to dump directly into the intake) and since the vehicle is not here and I did not have a fuel pressure checker with me I could not check pressure. I am taking that with me today when I go work on the truck again.

The truck motors/intake have the FPR built in correct?

The truck motors/harness are new to me, I have only ever done fbody and vette harness/motors. This is my first truck motor/harness. Just want to make sure Im not missing anything.

69LT1Bird

iTrader: (1)

The regulator is on the drivers side fuel rail and should have a vacuum line on it.

85irocinjected

here is a scan while cranking...I took the injectors off the heads to see any fuel and nothing! the motor sat for over a year. and the fuel smell carmalized like crazy. here is a log just to check. please tell me what yall see. NOTE the motor did not run during this scan...only multiple trys to start.

69LT1Bird

iTrader: (1)

If you pump cycles are key on and you do not have fuel at the rails, it is not in the tune.

Detail your fuel sysem. What kind of tank, where is the pump, what kind of filter and where is it located, pictures would also help. Return or returnsless.

85irocinjected

The fuel system is the return type and I have the line going directly back into the tank. The tank is located about 3-4 feet from engine (behind driver seat) and the fuel pump is between the engine and tank.Its a steel tank from a 88 c10 with the pickup on the top of the tank.

Have plenty of fuel in the rails. so we went ahead and took the injectors completely out of the vehicle and are cleaning them...they are going to sit overnight to dry out then be put back on the engine in the morning. When we took them off the vehicle and inspected them they where filthy and you could just see build up everywhere and during cleaning all kinds of junk came out of them...hopefully this is the problem.

ryanvv355

iTrader: (17)

I find it hard to believe all eight are gummed up so bad that not so much as a proverbial drip comes out of them, but who knows.

69LT1Bird

iTrader: (1)

Also, it is flat out dangerous to lift the fuel rail out of the intake and turn the fuel pump on, you are just itching for a fire. Use common sense, if you don't have a service manual or the correct tools, take it to someone who does.

What do you consider plenty of fuel at the rails and how to you know that?

85irocinjected

The engine was cold so I was not worried about any sort of fire plus we have a few fire extinguishers around the shop. I consider plenty of fuel in the rails when they are completely full of fuel. Then when emptied they completely fill again in no time.

The owner of the motor talked to the junk yard where he got it from and they said they have had that motor for a good 3 years. It only has 30000+ original miles so the fuel system could be completely clogged with junk.. I have yet to be able to put it back together and try so no update yet.