1990 Chevy Truck fuel pump

Tiny
BOBFRANK
  • MEMBER
  • 1990 CHEVROLET TRUCK
Electrical problem
1990 Chevy Truck V8 Two Wheel Drive Manual

Have a 1990 3500 chevy truck. Fuel pump runs with key off. It will shut off after 5-10 minutes. Misses while idling. Have check relay and fuse. Both good. Where is fuel pump oil pressure switch and could a faulty one be causing this?
Do you
have the same problem?
Yes
No
Saturday, January 31st, 2009 AT 5:00 PM

9 Replies

Tiny
BOWTIE BABY
  • MEMBER
I dont know what you meen by fuel pump oil pressure switch. The electric pump will have a fuel pressure switch built in. Have you checked the ignitioon switch and ignition relays.
Was this
answer
helpful?
Yes
No
-1
Friday, February 6th, 2009 AT 2:37 AM
Tiny
BOBFRANK
  • MEMBER
Oil pressure switch is located behind distr. Unhooked it and fuel pump shuts off. Put new one on and pump is doing same thing. Showed high oil pressure all the time, then when I unplugged it it showed hi pressure at start up and then none when key off. With new switch, it shows 60 lb at start up and bleeds down to half way when key shut off. Also check gauges lite is coming on with new switch.
Was this
answer
helpful?
Yes
No
Tuesday, February 10th, 2009 AT 7:48 PM
Tiny
BOWTIE BABY
  • MEMBER
If your check guages lite is coming on it will store fault codes in the computer. You can pick up a scanner for about $30. That will help you pinpoint the problem more accurately.
Was this
answer
helpful?
Yes
No
Tuesday, February 10th, 2009 AT 7:55 PM
Tiny
BOBFRANK
  • MEMBER
[Computer will not store codes as I have to unhook bat cable for pump to shut off. Replaced ignition switch and it is still doing it. When I unhook ing switch the pump runs right. Help
Was this
answer
helpful?
Yes
No
Saturday, February 14th, 2009 AT 12:14 PM
Tiny
BOWTIE BABY
  • MEMBER
Wow thats a weird one. Did you ever have any wiring problems in the past, wires melted together or anything like that. Maybe you got a bad switch from the parts store.
Was this
answer
helpful?
Yes
No
Saturday, February 14th, 2009 AT 3:17 PM
Tiny
BOBFRANK
  • MEMBER
No tank was full of rust and stuff, so fuel pump burnt up. Cleaned tank out, new pump and filter and ever since it has done this. Have also put a computer in it. Any suggestions? THANKS
Was this
answer
helpful?
Yes
No
Sunday, February 15th, 2009 AT 6:26 PM
Tiny
BOWTIE BABY
  • MEMBER
How many wires are on the oil pressure switch? It could have a safety feature so if you lose oil pressure the fuel pump will shut off, Try replacing the oil presure switch again. It could be faulty out of the box.
Was this
answer
helpful?
Yes
No
Sunday, February 15th, 2009 AT 8:02 PM
Tiny
BOBFRANK
  • MEMBER
Tried that, put a oil pressure switch from another truck and it still does not shut off. The ops has 3 wires. Checked for voltage at fuel pump fuse under hood and check lite is very brite on one side and then dimmer on other side. Checked fuse on the other truck and check lite only lites up on one side while fuel pump is pumping. Can hear the relay click in and then something else clicks. From listening to the other truck, the other click is when the fuel pump is getting ready to shut off. Then something clicks and then the relay clicks. Weird.
Was this
answer
helpful?
Yes
No
Monday, February 16th, 2009 AT 4:30 PM
Tiny
BOWTIE BABY
  • MEMBER
Have you replaced or switched the relay with the other truck. If it sounds funny and power is in different places than the other truck it may be a bad relay bad.
Was this
answer
helpful?
Yes
No
Tuesday, February 17th, 2009 AT 6:24 PM

Please login or register to post a reply.

Recommended Guides