smithoman

I put in a new fuel pump yesterday and I'll spare the details of how I hooked up the power backwards..... figured that all out but now I have absolutely no power to the pump. I've checked every fuse that I can find. Anybody out there know if there is fuse that controls the power to the fuel pump on a 92 4runner? I've read my crappy manuals and the electrical schematics don't even show a fuel pump! I'm really at a loss at this point. Thanks

DeathCougar

iTrader: (23)

Circuit open relay is one of them.

Is the fuel pump the ONLY thing that doesn't have power? Are you 100% sure you are not getting power to the fuel pump, ie you have tested it to make sure you are indeed no getting 12v to the pump, and that the pump circuit is the only issue?

mistreatedtoys

Are you checking with the key on or while cranking? Try both ways

smithoman

I am positive that there is no power to the pump. And I cannot find anything else on the vehicle that doesn't have power. I'm thinking that there is a fuseable link inline to the pump somewhere. But if so, where? I finally wired the pump directly to the battery with an inline fuse, switch and power light. That's how I finally got home after being stranded at my friends for a day and a half.

Thanks for the input. I'll post whatever I end up figuring out.

smithoman

Today I got a schematic from my friend who is a mechanic. The power to the fuel pump goes through the 15amp EFI fuse. The fuse is not blown in my car. But then the power goes through two different relay's. I'm certain that one of them got toasted being shorted out.

I was super careful putting in the new fuel pump but I was very tired. And the polarities on the new pump (which looked just like the old pump) are reverse. Of course there aren't any markings to actually tell a person this.... xtra crispy. I connected positive directly to ground.

One wierd thing, my check engine light finally went out (it's the only thing that was lacking power that I could find other then the pump) and then lit back up this afternoon. How do I get that thing to turn off?

Gordo

The pump only turns on when your cranking the engine. So if you just turn the key it will show no power. You'll need someone to crank the engine to verify if you have power. There is also a connection normally on the top of the gas tank. If that came disconnected you'll get no power.

smithoman

Thanks, that makes a lot of sense. I know the connection is ok. I'm going to troubleshoot the thing tomorrow. That cranking info is extremely helpfull. I have been wondering about that for days. I couldn't recall ever hearing that pump run just because the ignition was on. Thanks again!

thook

Hmmm.....if you look under the hood, locate the grey diagnostic port, and locate the FP and B+ terminals. Jump the terminals with a paper clip. Turn the key to the ignition position. Not the start position to start the vehicle, but the position the key falls back to from there. IOW, just past accessory position. All your dash lights (CEL, A/T temp light, ABS light, ect.) should come one. You should hear the fuel pump run. If not, then you have a wiring problem to the pump or at the pump. If it does run, then you have an issue with the fuel pump relay (aka circuit open relay) or the fuel pump switch in the airflow meter.

thook

BTW, DeathCougar's real name is Reginald.