11-16-2018, 02:23 PM
Hello
I have a 96 geo tracker 4door m/t.
I took off very quickly from a stop. Car stalled. No lights del or otherwise.
Checked fuses. Sign/coil fuse was blown. Relays chattering. Replaced fuse. Fuel pump would not energize. I ran a switched and fused wire from battery+ to pink+ black wire to get me home (way out in the woods off road )
Now, that i'm home I'm trying to diagnose the problem. my fuel pump will not run(or prime), suspecting ecm or wiring problem.
Steps taken.
Main relay check. -good
12v at blue/ black wire
12v at black/white
ECM triggers main at key on and sends power to fuel pump relay and ecm on blue black wire.
Fuel pump relay test
12v at blue/ black wire
12v at black/ white wire
12v power applied to pink black starts fuel pump
*Pink wire at fp relay*
**This is where I found confusion and need help
When testing the pink wire, it goes to 12v at key on, but does not close the relay. 0v to pink/black.
When the fuel pump relay is disconnected the pink wire shows 4.65v for three seconds then goes back to 0v.
****
Further tests
continuity good between ecm and relay on pink wire.
5v reference on tps wire.
12v at MAF sensor.
12v at distributor.
All fuses good and 12v on both sides of fuses and 12v back probing wires at fuse box.
Cel light is on with key.
Starts and runs good with fuel pump directly supplied 12v with fuse and switch. No hesitation or miss.
I also Grounded ecm case with copper stranded wires and loop connectors.
Pulled ecm and inspected for damage-none seen obvious to the eye. No heat, water, corrosion evidence obvious.
My questions.
I see several posts saying that the pink wire is supposed to supply a ground for three seconds at key on. How to test this ? Can I back probe the pink wire with the negative side of my metre and put the (red)+ side of my meter to 12v positive.
With relay removed pink wire shows 4.65v for three seconds at key on. (Positive of meter to pink wire, negative to body ground) Is this correct? If not what should the reading be?
If the results of these tests is showing the ECM is cutting fuel, what faults can cause this condition?
Anyone with more experience is welcome to ignore my questions and provide further diagnosis procedures. Sorry for the lengthy post I wanted to provide as much information as possible.
Thank you,
Sky
I have a 96 geo tracker 4door m/t.
I took off very quickly from a stop. Car stalled. No lights del or otherwise.
Checked fuses. Sign/coil fuse was blown. Relays chattering. Replaced fuse. Fuel pump would not energize. I ran a switched and fused wire from battery+ to pink+ black wire to get me home (way out in the woods off road )
Now, that i'm home I'm trying to diagnose the problem. my fuel pump will not run(or prime), suspecting ecm or wiring problem.
Steps taken.
Main relay check. -good
12v at blue/ black wire
12v at black/white
ECM triggers main at key on and sends power to fuel pump relay and ecm on blue black wire.
Fuel pump relay test
12v at blue/ black wire
12v at black/ white wire
12v power applied to pink black starts fuel pump
*Pink wire at fp relay*
**This is where I found confusion and need help
When testing the pink wire, it goes to 12v at key on, but does not close the relay. 0v to pink/black.
When the fuel pump relay is disconnected the pink wire shows 4.65v for three seconds then goes back to 0v.
****
Further tests
continuity good between ecm and relay on pink wire.
5v reference on tps wire.
12v at MAF sensor.
12v at distributor.
All fuses good and 12v on both sides of fuses and 12v back probing wires at fuse box.
Cel light is on with key.
Starts and runs good with fuel pump directly supplied 12v with fuse and switch. No hesitation or miss.
I also Grounded ecm case with copper stranded wires and loop connectors.
Pulled ecm and inspected for damage-none seen obvious to the eye. No heat, water, corrosion evidence obvious.
My questions.
I see several posts saying that the pink wire is supposed to supply a ground for three seconds at key on. How to test this ? Can I back probe the pink wire with the negative side of my metre and put the (red)+ side of my meter to 12v positive.
With relay removed pink wire shows 4.65v for three seconds at key on. (Positive of meter to pink wire, negative to body ground) Is this correct? If not what should the reading be?
If the results of these tests is showing the ECM is cutting fuel, what faults can cause this condition?
Anyone with more experience is welcome to ignore my questions and provide further diagnosis procedures. Sorry for the lengthy post I wanted to provide as much information as possible.
Thank you,
Sky