I’ve just bought a decent running ˟˟˟˟ box and I really like the truck. Standard transmission 3.0l 1992 four wheel drive pickup. I’ve bought the unit and find it runs fine but I noticed that the main efi relay is jumped out on the fuse box on the passenger side wheel well. I’ve tried replacing the relay with jobber relays from my work and it won’t run with a relay in place. It’s is jumped out from the 30 pin to the 87 pin then across from the 86 to the 85 and it will start and run fine but as soon as a relay goes in it won’t start. Trying to figure out if it’s a harness issue or am I using the wrong relay type. The stock Toyota relay is 75 dollars and I don’t wanna just throw it in and break it possibly if something is shorted. So trying to diagnose before parts changing. Any help would be nice

 

First off, jumping relays is very bad practice. That said, the 30 to 87 is the main circuit that you're trying to energize, in your case EFI. The 86 to 85 circuit is what closes the contacts inside the relay to let power transfer from 30 to 87. If 30 and 87 are jumped, you are directly bypassing the relay. Jumping 86 to 85 will create a direct short to ground, so that is odd that you found that.
I'm assuming you did remove the jumpers before testing the new relays?

 

As moto809 said, You don't really want to do that.
IIRC that fuel pump relay is actually 'powered' (that's the 85/86 connections current) by the COR (circuit opening relay). That little puppy gets powered when the ECU gets correct combo of signals from VFM or whatnot that says the vehicle is actually 'running', thus allowing the fuel pump to run. And most important to NOT run when the motor is actually not actually burning fuel. Which helps in the NotBurnTruckDown department. More worthless thoughts; since all them jumpers were in place, they are then using the wires that feed into that relay (at least seems to me). So those probably aren't really much of a problem.

I've actually built a spare tank with toyota internals. It's just a fancy "jerry can" that doesn't really hang on the back bumper. Anyway, its a transfer tank only (that hopefully) will also display level on my dash guage. And ITS fuel pump power (via a switch) actually is "hotted" by that same COR. I ran that thru another relay that feeds +B power for that second pump.

Disclaimer : this is all in minecraft or whatever you kids say, 'cuz I haven't even gotten the tranny back in yet.
I need to start a build thread. (Actually that woulda been great cuz I spent a WEEK trying to figure out wiring i'd done and cjouldn't find schematics.)

 

Coopster I feel like it's been ages since Ive seen you! Yeah you need a build thread, I wanna see it!