GMC SERRIA

1991 GMC SIERRA
220,000 MILES • V8 • 4WD • AUTOMATIC
Avatar
HALLWILLIAM 72
  • MEMBER
  • 2 POSTS
91Gmc Serria has no fuel and no fire power to the fuel pump with the key in the on position but no power to the the pump in the start position no fire at any time. replace the ecm ,fuel pump,fuel pump relay, ingnition switch, oil pressure switch
Jan 17, 2011 at 8:39 AM
Advertisement
Avatar
JDL
  • ✓Experienced Mechanic
  • 16,098 POSTS
Did you check the inline fuse? Should be close to fuel pump relay.
Image (Click to enlarge)
Attached Media
Jan 17, 2011 at 8:54 AM
Avatar
HALLWILLIAM 72
  • MEMBER
  • 2 POSTS
Yes checked the inline fuse with a test light it has power to the fuel pump in the on position for 2 sec and then goes out but in the start position no power to the fuel pump and there is no spark coming from the distributor or coil
Jan 17, 2011 at 9:26 AM
Avatar
JDL
  • ✓Experienced Mechanic
  • 16,098 POSTS
In the diagram, check gray fusible link. That is hot all the time. Supplies voltage to both the o/p switch and the load side of fuel pump relay.
Image (Click to enlarge)
Attached Media
Jan 17, 2011 at 10:04 AM
Avatar
JDL
  • ✓Experienced Mechanic
  • 16,098 POSTS
The fusible link should be at the battery junction box on the firewall.
Image (Click to enlarge)
Attached Media
Jan 17, 2011 at 10:09 AM
Avatar
FORD MAN
  • MEMBER
  • 115 POSTS
It might be something as simple as bad/no grounds between body & motor,
or something as difficult as finding bad/broken wires. Happy Hunting !

Ford Man in Michigan
Jan 17, 2011 at 10:16 AM
Avatar
JDL
  • ✓Experienced Mechanic
  • 16,098 POSTS
Did you get it going?
Mar 2, 2011 at 2:20 PM
Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Ask a new question

Frequently Asked Problems for This Vehicle