Fuel Pump circuit not receiving power

I

ibosley

New member
1998 4x4 v6

The fuel pump will not turn on. I have jumped the terminals and verified that it still works. I have also checked both relays and ECM fuses and they are fine. I am not getting power to the back.

The car was recently involved in a front end collision but that was a month ago. It just now sputtered and died. Is there a crash sensor somewhere in the circuit or could I just have a bad ground somewhere?

And this icon is hilarious: So Gay
 
Register to hide this ad
That is not the issue. It went dead during regular driving conditions and the circuit hasn't been hot since.
 
Test the circuit under the fuse block. Check for power, ground and signal.


Will the truck start up if you jump power to the fuel pump?
 
I'm sure it would start if I were to hack the fuel pump to the on position and also crank it. I haven't done so though. I know it is in time and has spark because I shot a little bit of ether in it.

I have checked both fuses and both relays in the circuit, but I haven't checked anything to see where it stops being hot. I was wondering if there were any additional cuttoff sensors I need to be looking at.
 
At the fuel pump relay:

terminal 1 From 10amp ignition fuse (splits to E15 at ECU (power to ECU), terminal 3 of "stop light switch"

terminal 2 From ECU terminal E22

terminal 3 Power out to fuel pump

terminal 5 Comes from a junction block that powers multiple other sensors. If you have 12v at the B+ in the diagnostic block under the hood then this circuit should have power.

So if you have power on terminal 1 and terminal 5 and see ground to terminal 2 when you turn the ign on/crank then everything should be good. What part of that equation is missing?
 
Last edited:
Nevermind, B+ is hot in run, as it should be. I can't find a terminal map but I believe that circuit is behaving as you described. I'm starting to think there is a bad ground at the pump. I'll get back to you.
 
Yep, the orange/blue wire to the pump is hot when grounded to the battery, but not when grounded to the harness.
 
ibosley said:
1998 4x4 v6

The fuel pump will not turn on. I have jumped the terminals and verified that it still works. I have also checked both relays and ECM fuses and they are fine. I am not getting power to the back.

The car was recently involved in a front end collision but that was a month ago. It just now sputtered and died. Is there a crash sensor somewhere in the circuit or could I just have a bad ground somewhere?

And this icon is hilarious: So Gay
Click to expand...

What terminals did you jump to check the pump , I need to do the same thing.what color are the wires on the plug ?
 
I’ve been having the same issue with my 95. I just bought it and the guy said he had driven it fine a couple weeks before I came to check it out but it just cranks. I replaced the pump but it seems that no power is being sent to it. I checked the EFI relay and it’s working, how would I go about diagnosing the issue? I’m pretty new to this stuff so I’ve been blindly poking around with a multimeter like an idiot
 
Recap and summary please

I have a 1997 Toyota 4runner.

Recently bought less than 2 months ago. I drove it to lunch, had lunch, came out, started it, it started and it immediately died. Checked all the common things (battery, fuses, relays, etc) No Fuel. Ran when adding aresol combustible fumes, but died once the fumes were gone.

Trucked it back home and dropped the tank. Replaced the fuel pump.

No fuel.

Bench tested the pump, and it works good. Okay so now retest the power to the pump (initially paid a mobile mechanic to diagnose and he said it had power, which is why i decided to change the fuel pump).

No power from the relay to the pump, no power from the ECM to the relay. B+ diagnoses has power. ECM voltage readings at E1, FC, and B+ are minimal or 0.

change the ECM?
 
ECM does not power relay..!!
7.5a (fuse) to EFI relay
15a (fuse) to pin 5 EFI relay out on pin 3 to..
Circuit Opening Relay . . . B+ on pins 5 and 1 (from EFI relay)
B+ out on pin 3 to pump / pin 2 COR grounds (control) through ECM !!
 
You must log in or register to reply here.

Members online

Total: 298 (members: 2, guests: 296)

Forum statistics

Threads
278,310
Messages
3,554,080
Members
248,016
Latest member
Advally Service

Share this page

Trending content

Back
Top