WhalePirot
Well-known member
From my signature, you'll see that I have changed my '84 to a TPI'd 406. My harness was modified by Jim's Perf. in VA to run a '90 Camaro ECM in the stock mounts, with a custom PROM.
It recently developed a problem that I am using my '84 wiring diagram to track down, but I'd appreciate input to speed the process from U guys who have and can use a wiring diagram.
My fuel pump does not kick on for the 5 sec. or so, when I turn on the key. I get battery voltage at the fuse and at the 'hot' pin on the relay, but it decreases to GND as I check it with my DVOM. What is strange is that I can jump the fuse to BATT and start the car, which will continue to run with the jumper removed. It will also restart for many hours, following shutdown. I believe this to be a result of the fuel rail holding residual pressure.
The 'hot' pin on the fuel pump relay has two feeds. One is through the oil pressure switch, the other from the ECM. I am trying not to make a major project out of this, as y'all know how tight the workspace is. It seems I have an electrical 'leak'(short) that is preventing, then draining the kick-on signal, but am unsure how to easily find it. I could separate the two leads and check for GND. I know I have had heat issues and might have a compromised, shorted wire in the rear engine area or a bad oil pressure switch.
The ECM must feed battery voltage, not GND to the relay, right? Maybe this side is bleeding off the BATT voltage when shutdown?
As the car will keep runing, once started, I think I can figure the oil pressure switch side is fine.
I will appreciate input from a second set of eyes. Thanks. mike
It recently developed a problem that I am using my '84 wiring diagram to track down, but I'd appreciate input to speed the process from U guys who have and can use a wiring diagram.
My fuel pump does not kick on for the 5 sec. or so, when I turn on the key. I get battery voltage at the fuse and at the 'hot' pin on the relay, but it decreases to GND as I check it with my DVOM. What is strange is that I can jump the fuse to BATT and start the car, which will continue to run with the jumper removed. It will also restart for many hours, following shutdown. I believe this to be a result of the fuel rail holding residual pressure.
The 'hot' pin on the fuel pump relay has two feeds. One is through the oil pressure switch, the other from the ECM. I am trying not to make a major project out of this, as y'all know how tight the workspace is. It seems I have an electrical 'leak'(short) that is preventing, then draining the kick-on signal, but am unsure how to easily find it. I could separate the two leads and check for GND. I know I have had heat issues and might have a compromised, shorted wire in the rear engine area or a bad oil pressure switch.
The ECM must feed battery voltage, not GND to the relay, right? Maybe this side is bleeding off the BATT voltage when shutdown?
As the car will keep runing, once started, I think I can figure the oil pressure switch side is fine.
I will appreciate input from a second set of eyes. Thanks. mike