I think I shorted out either my fuel pump or ECM
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Junior Member
Joined: Nov 2003
Posts: 4
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From: Bakersfield, CA
Car: 88 Trans Am
Engine: 305 bored .060 0ver
Transmission: Auto
I think I shorted out either my fuel pump or ECM
I just recently rebuilt the engine in my 88 TA and when I got it back in it fired right up and run perfect, except that the cooling fans wouldn't kick on. I was working with a friend who used to be a mechanic and we decided to try to short across the fan relay to try to get the fans to turn on. He pointed out the wrong relay so we accidentally shorted out the fuel pump relay instead. So now when the car trys to start you can't even hear the fuel pump "whine" and the "check engine soon" light doesn't come on either. I think I found the correct in-line fuel pump fuse and it checks out ok ( if that was the correct one). Any thoughts on roughly how screwed I am??
Thanks for any help
Thanks for any help
Supreme Member
Joined: Aug 2001
Posts: 1,896
Likes: 1
From: Warrington, PA USA
Car: "02 z-28
Engine: LS-1
Transmission: 4L60E
If you shorted only the contact side of the relay there should be no problem. If you shorted across the coil of the relay and put raw 12 volts to the ECM controlled side of the relay coil you probably blew the driver inside the ECM.
Junior Member
Joined: Apr 2003
Posts: 90
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From: Mount Forest, Ontario, Canada
Car: 1990 RS
Engine: 305
Transmission: T-5
You may have simply blown the fusible link that governs both the ECM and the fule pump.
There have been several discusions about the fusible links a few months ago.
There have been several discusions about the fusible links a few months ago.
TGO Supporter
Joined: Sep 2003
Posts: 6,127
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From: conway, s.c.
Car: 1989 Iroc-Z
Engine: 5.7L TPI
Transmission: 700R4
If you shorted out the fuel pump relay, what you have done is blow the 20 amp fuel pump/ecm fuse that is located under the hood somewhere near the battery. If it blows, the ECM won't work.
The Trickster!!!!!!!!
The Trickster!!!!!!!!
Thread Starter
Junior Member
Joined: Nov 2003
Posts: 4
Likes: 0
From: Bakersfield, CA
Car: 88 Trans Am
Engine: 305 bored .060 0ver
Transmission: Auto
There are no fuses under the hood by the battery that I know of, I know my 96 Z28 had the "convienance" fuse block under the hood, but this car doesn't, the only fuse that I found under the hood was pointed out to me by autozone, and according to the schematic there is a fuse that goes to the fuel pump. I have heard from people that if the ECM blew then the fuel pump would still fire up, does that make any sense to you guys, it doesn't to me. What would be the next course of troubleshooting to figure out exactly what I have done?
Again thanks for all the input!
Again thanks for all the input!
Thread Starter
Junior Member
Joined: Nov 2003
Posts: 4
Likes: 0
From: Bakersfield, CA
Car: 88 Trans Am
Engine: 305 bored .060 0ver
Transmission: Auto
Also I have checked all the fuses under the dash and they have all been replaced even though they checked out good
Junior Member
Joined: Apr 2003
Posts: 90
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From: Mount Forest, Ontario, Canada
Car: 1990 RS
Engine: 305
Transmission: T-5
Go here to see one of the previous discussions and to see a picture of the fuse location.
https://www.thirdgen.org/techbb2/sho...hreadid=190776
https://www.thirdgen.org/techbb2/sho...hreadid=190776
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TGO Supporter
Joined: Sep 2003
Posts: 6,127
Likes: 12
From: conway, s.c.
Car: 1989 Iroc-Z
Engine: 5.7L TPI
Transmission: 700R4
As mentioned earlier, the fuse under the hood is for the fuel pump/ecm. If this fuse blows, the ECM and anything that is controlled by the ECM will not work. What you are thinking about is that if the fuel pump relay goes bad, then the oil pump will run the fuel pump once it builds up pressure. Go to the link that HeavyBreathinRS has posted and you will find your problem. It is an easy and inexpensive fix. I have had this problem three times because of shorted wires in my fuel pump relay wire harness.
The Trickster!!!!!!!!!!!!!
The Trickster!!!!!!!!!!!!!
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Joined: Aug 2003
Posts: 7,240
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From: LeRoy, NY
Car: 2003 Hyundai Tiburon GT
Engine: 2.7L V6
Transmission: 6-speed
Axle/Gears: 4.41
I don't know about Camaro's, but on my 'bird there's TWO fuses on the ECM side of the car. One may be for the ECM and the other for the F/P, but I can't tell which, I have the same problem, and both fuses are good. New ECM time for me!
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