1986 GMC S15 WONT START

  • Tiny
  • Derbyguy74
  • 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.

Do you
have the same problem?
Yes
No
Sunday, March 21st, 2010 AT 8:18 PM

12 Replies

  • Tiny
  • Rasmataz
  • MEMBER

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-

Was this
answer
helpful?
Yes
No
Sunday, March 21st, 2010 AT 8:28 PM
  • Tiny
  • Derbyguy74
  • MEMBER

Noid lite?

Was this
answer
helpful?
Yes
No
Sunday, March 21st, 2010 AT 10:18 PM
  • Tiny
  • Derbyguy74
  • MEMBER

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?

Was this
answer
helpful?
Yes
No
Sunday, March 21st, 2010 AT 10:22 PM
  • Tiny
  • Rasmataz
  • MEMBER

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

Was this
answer
helpful?
Yes
No
Sunday, March 21st, 2010 AT 11:59 PM
  • Tiny
  • Derbyguy74
  • MEMBER

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

Was this
answer
helpful?
Yes
No
Monday, March 22nd, 2010 AT 12:31 AM
  • Tiny
  • Rasmataz
  • MEMBER

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

Was this
answer
helpful?
Yes
No
Monday, March 22nd, 2010 AT 7:27 AM
  • Tiny
  • Derbyguy74
  • MEMBER

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

Was this
answer
helpful?
Yes
No
Monday, March 22nd, 2010 AT 12:27 PM
  • Tiny
  • Derbyguy74
  • MEMBER

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.

Was this
answer
helpful?
Yes
No
Monday, March 22nd, 2010 AT 2:32 PM
  • Tiny
  • Rasmataz
  • MEMBER

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

Was this
answer
helpful?
Yes
No
Monday, March 22nd, 2010 AT 3:28 PM
  • Tiny
  • Derbyguy74
  • MEMBER

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.

Was this
answer
helpful?
Yes
No
Thursday, March 25th, 2010 AT 5:58 PM

Please login or register to post a reply.

Other Engine No Start Questions