billabong2442

Hello, I am new to this forum and I need some help with my 3.0l. I recently put a new motor in my truck and now I have encountered a problem. When I turn the headlights on, the fuel starts pumping into the fuel rail. I never disconnected the headlights or anything and now this is happening. If anyone has any information on this, I need your knowledge.

CappyKD

can you post up pics of where the fuel is coming from?

billabong2442

here is where its pouring out when I turn the headlights on

sb5walker

The thing you're pointing at is the fuel pulsation damper - it's like a shock absorber for fuel pressure that evens out the spikes and drops in pressure as the injectors open and close. It's the most common location for fuel leaks on the 3vze. Do you have new copper or aluminum gaskets on both sides of that banjo fitting? If not, that's probably why it's leaking. But if you need a new pulsation damper, 1sttoyotaparts.com sells the dealer part for around $95; a Standard Motor Parts one from rockauto will be a little cheaper.

But that doesn't explain why the fuel pump turns on with the headlights. First, check the gray plastic diagnostic check connector and make sure there are no jumpers in there.

The pump normally operates off the circuit opening relay which is in the passenger kick panel - nowhere near any headlight power leads. But there are a couple possible locations of trouble. The COR is triggered by a feed off the ignition switch so the pump will run while you're cranking it. The ignition switch isn't far from the wires leading into and out of the headlight (combination) switch. So you might check for a short in the column.

Another possibility is there's an extension of the pump's power lead in the check connector - and that's attached to the fuse/relay block where the headlight relay lives. So there's a chance for a short in that area too.

The other trigger of the COR is the fuel pump switch in the air meter, which keeps the COR triggered while the motor is running. Wires go from there to the COR, but I don't know of any place where a headlight power lead would cross it. There could be such a place, but I just don't know the routing of that wire & the headlight leads well enough.

The last place I can think of is in the harness leading from the FRB to the cab, up to the place where the pump lead splits off from the harness. I have no idea where that split is; if you don't find an obvious short in the column or FRB, you might try tracing the pump's power lead forward until it joins the wiring harness (if it does) and look closely between there & the FRB.

Good luck! Electrical problems can be slippery.

billabong2442

Thanks for the info, i will check those spots for shorts and let u know if i find the problem