monsterchevylizzard

I have transplanted an ls1 into an s-10 for off road use. I installed a jegs fuel cell and accell 45 psi inline pump. I had a custom harness done by ls1performanceparts.com and he will not help me with the installation. I didnt know how to wire the fuel pump, so I have it on a 12 volt switch. When I start the engine with the fuel pump off the engine starts and runs for aproximatley 5 seconds and cuts off. If I turn the fuel on, the engine dies out anyway. I have run the truck very smoothly for 1 minute just spraying starter fluid in the intake, but when I add fuel, it cuts out. I think the fuel pump should be relayed somehow perhaps with the oil pressure or something. I cant tell if the motor is starving or drowning. New plugs, new coil packs, new wires, has a regulator on the fuel rail, and vats have been removed. Any ideas please ?

monsterchevylizzard

How come stock fuel tanks have 3 wires on the fuel pump ? Is there a built in relay ?

zapp168

iTrader: (7)

You should be able to run the pump off of an ignition feed, Ignition on, pump on. there are 3 wires on a stock sender 12 volt....ground.....and sending unit for the gauge. Did you hook up a fuel preasure gauge to make sure you are getting enough fuel preasure?

monsterchevylizzard

Well, I just bought a rail mount fuel guage off of ebay to see what I am getting at the injectors, but . . . I am not all that sure the problem is with the pump at this point. I am not sure, but does the return line on this engine recirculate gas when the engine is not currently running and the fuel pump is on ? Is there some kind of vacuum that controls the gas recirculation when the engine is off ?

I am missing what looks like a vacuum sensor plug-in on the wiring harness that I though just controlled the egr. It is a plug-in that is nearby the fuel rail on top of the engine just behind the pressure regulator, but I dont see how it would connect to the fuel system ? Think that might be controlling a bypass loop on the fuel system ? Anyone ?

monsterchevylizzard

I have seen two plug-ins for a stock fuel tank. One is the sending unit that has 2 wires. One is a fuel pump that has 3 wires. An aftermarket pump has only connections for 2 wires ? What is the third wire for ? (Or am I not thinking correctly ?)

If I ran the pump simply off of an ignition wire; when the power to the pump is on and the engine is off, the fuel pump makes an AWFUL noise like a bunch of hornets surrounding a nest.



man this is hurting my head.

MakoLS1

Is the car running when you give it gas, or will it just not idle? I jsut put another motor in my car and couldnt find why it wouldnt idle for anything. Come to find out one of the vacum hoses behind the intake was completely loose.

monsterchevylizzard

If i attempt to give the car gas, it dies out really quick ( with the fuel pump on and off). The only vacuum line that I can see is unplugged, is the agr line because I have them blocked off.

monsterchevylizzard

Does anyone know how the return line is activated to return the fuel instead of holding it in the fuel rail, or does it even work that way ? Is it controlled by vacuum ? What is the little black cylinder just before the fuel return line ?

zapp168

iTrader: (7)

I know if you unplug the MAF the motor will idle, but die as soon as you touch the pedal. I believe the regulator for the LS1 maybe in the tank as part of the pump unit, I will look at my fuel rail and see if there is a regulator as part of it, and I will look at All data when I get to work on Tues