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1986 GMC S15 Repair Question


Topics covered: Fuel pump, Fuse, Fuel pump relay.
Mileage: No information provided.

Asked on March 21, 2010

1986 GMC S15 Wont start

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.
Avatar Asked by derbyguy74

Answer

Replied on 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-

Tiny Answered by rasmataz
68 questions asked
Replied on March 21, 2010

Noid lite?

Tiny Response from derbyguy74
2 questions asked
Replied on March 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 Response from derbyguy74
2 questions asked

Replied on March 21, 2010

The fuel pump relay,oil pressure switch, fuel pump and computer

Tiny Answered by rasmataz
68 questions asked
Replied on March 22, 2010

The manual says the ECM I fuse is the computer and that fuse is fine.

Tiny Response from derbyguy74
2 questions asked
Replied on March 22, 2010

Mit1 says it powers the items I've mentioned earlier I viewed the electrical diagram/schematics

Tiny Answered by rasmataz
68 questions asked

Replied on March 22, 2010

Is the fuel pump relay under the hood? There are 3 relays under the hood.

Tiny Response from derbyguy74
2 questions asked
Replied on March 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 Response from derbyguy74
2 questions asked
Replied on March 22, 2010

S15 2.8 liter the FP relay is located on left front fender panel behind AC compressor relay-Sorry no pic available.

Tiny Answered by rasmataz
68 questions asked
Replied on March 25, 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 Response from derbyguy74
2 questions asked