Mechanics

WONT START

1986 GMC S15

Electrical problem
1986 GMC S15 6 cyl Two Wheel Drive Manual 171428 miles

My truck wont start. It has spark and fuel to the throttle body but the injectorswont pulsate fuel. If I spary starting fluid in it it runs fine for a minute.
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Derbyguy74
March 21, 2010.




Hook up a noid lite to the injector/s harness and see if it flashes if so the injector/s is the problem no flashes could mean power input or the computer injector/s ground drivers-

Rasmataz
Mar 21, 2010.
Noid lite?

Tiny
Derbyguy74
Mar 21, 2010.
The ecm b fuse blew and when I put a new one in it blows imedeitley. I checked the wires that go to the fuel pump and they were fine. The ECM B fuse is the fuel pump. What else runs off that fuse?

Tiny
Derbyguy74
Mar 21, 2010.
The fuel pump relay, oil pressure switch, fuel pump and computer

Rasmataz
Mar 21, 2010.
The manual says the ECM I fuse is the computer and that fuse is fine.

Tiny
Derbyguy74
Mar 22, 2010.
Mit1 says it powers the items I've mentioned earlier I viewed the electrical diagram/schematics

Rasmataz
Mar 22, 2010.
Is the fuel pump relay under the hood? There are 3 relays under the hood.
AD

Tiny
Derbyguy74
Mar 22, 2010.
So I looked at the three relays under the hood on the drivers side fender and the middle relay looks like it fried because the plug and bottom of the relay are black. I cant read the numbers on the relay so I cant cross refrence tot see if it the fuel pump relay.

Tiny
Derbyguy74
Mar 22, 2010.
S15 2.8 liter the FP relay is located on left front fender panel behind AC compressor relay-Sorry no pic available.

Rasmataz
Mar 22, 2010.
Ok. I have replaced the fuel pump relay, ignition control module, computer and oil pressure sensor. It still blows the ECMB fuse even when the computer is unplugged and the key is off.

Tiny
Derbyguy74
Mar 25, 2010.

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