FP/INJ -- fuse blowing

Boxcars

Banned
look at where the injector harness passes by the egr valve. they are known to short there. and if you are having thermal shorts that would make sense. becaue you wont have heat there until you made a few wot passes. hope this helps. Fred

I've eliminated the injector harness as the problem by unplugging it. The fuse still blew when I turned the key back on. :(
 

No disintegrations

Well-Known Member
I've eliminated the injector harness as the problem by unplugging it. The fuse still blew when I turned the key back on. :(
Oh so now it won't run.
Does the fp still prime? Or fuse instantly blows?
Keep trying fuses and wiggle various parts of that circuit. At some point the may not blow. That would mean the last part wiggled is suspect. It's called the wiggle test. Lol
 

Boxcars

Banned
Oh so now it won't run.
Does the fp still prime? Or fuse instantly blows?
Keep trying fuses and wiggle various parts of that circuit. At some point the may not blow. That would mean the last part wiggled is suspect. It's called the wiggle test. Lol

No, it's running normally unless I go to WOT.. I unplugged the injector harness after my last test drive at WOT-- see post #4. When the car shuts down, at first blows fuses. That is when I eliminated the injector harness from the circuit, but the fuse still blew. I won't have time to deal with it for a couple days. I have to locate my oil sender wires and make sure they're secure, and also the fuel related wire, the fuel pump prime connector located behind the alternator.
 
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salvageV6

Daily Driver
It can be the gray fuel pump prime connector moving and shorting on the header (hot) when driving etc.

When the car cools down the insulation may solidify and keep it an open circuit until you heat the car up again.

Look behind the alternator down lower in that harness for the prime wire and make sure it's intact and away from hot stuff, same with the oil pressure gray fuel pump wire in the front of the motor, make sure it was cut/removed and secured properly.
 

Boxcars

Banned
It can be the gray fuel pump prime connector moving and shorting on the header (hot) when driving etc.

When the car cools down the insulation may solidify and keep it an open circuit until you heat the car up again.

Look behind the alternator down lower in that harness for the prime wire and make sure it's intact and away from hot stuff, same with the oil pressure gray fuel pump wire in the front of the motor, make sure it was cut/removed and secured properly.

Oh, it's grey. Yes I have that wire connected to something. I'll have to trace it out and make sure it's not the problem. Thanks Alan.
 

Boxcars

Banned
It can be the gray fuel pump prime connector moving and shorting on the header (hot) when driving etc.
.

Question: What color are the wires that plug into the oil pressure sender switch? Is it gray too? I thought there is more than one. I cut them off years ago to eliminate the gummy plug and I also want to make sure they're not shorting anywhere. I remember, over the years since I installed this harness on my El Camino hybrid, some time ago the oil pressure idiot light used to flash intermittently. I didn't think too much about it since I knew the oil pressure switch was not connected. Maybe the problem has graduated to fuse blowing.
dunno.gif
 

Boxcars

Banned
Pink and black
Tan and white
Black

The pink and black would be the one shorting to ground.

OK, got back to work on it this morning and I think it's fixed. I went WOT three times and no problem. I thought I had cut off the three wire harness to the oil pressure switch plug on this car, but evidently, that must have been on some TR I had owned or worked on. That harness, by the way has a pink w/ black wire, a tan w/ white wire, and a grey wire -- not black for those who will deal with this problem in the future. The grey wire is the same same circuit as the fuel pump prime wire. Anyway, I located the suspect wiring for the oil pressure sender plug, and rather than running down the passenger side of the timing cover as it would have originally, it seemed jammed down the driver side of the timing cover. I had to pull it up and at the end was the super gummy plug. I pulled what was left of the plug off with my fingers and cleaned up the ends of the wires and taped them. I also had changed the FP relay, just in case, and this problem also led me to discover my ignition module was melting. So, all in all, I'm happy I found the problem and much thanks to all of you for sharing your expertise and suggestions. :)
 

salvageV6

Daily Driver
Yup gray out of the fuel pump relay, oil pressure switch and prime wire, all gray.

Spliced at splice S115 to a single gray wire that goes into the C100 connector under the power master/wiper motor area and into the car via a tan/wht wire.
 

TurboBuRick

Moderator
Staff member
Yup gray out of the fuel pump relay, oil pressure switch and prime wire, all gray.

Spliced at splice S115 to a single gray wire that goes into the C100 connector under the power master/wiper motor area and into the car via a tan/wht wire.

Thanks for the pointing that out. Something doesn't add up with the wires colors compared to the diagram. Thats what I was going off of. But if I had thought about it for a second I know the fuel pump wire is grey. :banghead:

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