SPONSORED LINKS

Fuel pump relay?

Tiny
GLENN37
  • MEMBER
  • 1989 CHEVROLET SILVERADO
Engine Mechanical problem
1989 Chevy Silverado V8 Two Wheel Drive Automatic 122, oo miles

I replaced the fuel pump relay then the oil sending unit the two wire one. The fuel pump has two quick sounds still will not crank after tring for a while it will crank but will not run long sounds good while running thanks
SPONSORED LINKS
Friday, September 5th, 2008 AT 3:06 PM

34 Replies

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Test the coolant temperature sensor if okay check the fuel pressure to rule out a failing fuel pump or a pressure regulator not maintaining the fuel pressure.
Was this
answer
helpful?
Yes
No
-1
Friday, September 5th, 2008 AT 3:41 PM
Tiny
WPRIMM
  • MEMBER
  • 1 POST
  • 1989 CHEVROLET SILVERADO
  • V8
  • 2WD
  • AUTOMATIC
  • 100,000 MILES
I thought my fuel pump was bad when I tried to start it and it would just crank, and no fuel was getting to the injectors. So I changed the pump and filter and still no fuel is getting to the injectors, and I cant hear any noise from the pump. Also I noticed that the fuel guage was working with the old "broken" pump but now reads empty with the new one (has about 3/4 a tank of gas in it) dont know if its the fuel relay or an electrical problem, I checked all the inside fuses but their fine.
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
-2
Tuesday, July 7th, 2020 AT 1:37 PM (Merged)
Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
Hello, did you check wiring at the fuel pump relay, orange wire is hot all the time? The gray wire carries voltage for the pump. If you use a jumper between those two terminals, the pump should run, use an inline fuse. Any fuse you check, also check that the fuse circuit is hot.
Was this
answer
helpful?
Yes
No
+5
Tuesday, July 7th, 2020 AT 1:37 PM (Merged)
Tiny
REDNECK447
  • MEMBER
  • 11 POSTS
Make sure power is going to your engine
Was this
answer
helpful?
Yes
No
-1
Tuesday, July 7th, 2020 AT 1:38 PM (Merged)
Tiny
EAGLE_ONE_20
  • MEMBER
  • 1 POST
  • 1989 CHEVROLET SILVERADO
  • V8
  • 4WD
  • AUTOMATIC
  • 180,000 MILES
Truck is not getting power to fuel pump I have power to the red wire in middle of conector and power to purple wire that goes in the tank to the float or gas gage but no power to fuel pump. It has good ground I even ran two ground wires of the ground to see if that helped it did not. I have put a new fuel pump relay fuel filter and a tps. Still nothing im lost please help
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
+1
Tuesday, July 7th, 2020 AT 1:38 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
The fuel pump will only power up for 2 secs due to the fuel pump relay de-energizing. The computer energizes the relay thru its fuel pump control

Have you tried direct power to the fuel pump? If it comes on when direct power is use and the relay has been replaced. Test the wirng-wiring okay, Test computer fuel pump control and fuel pump and oil pressure sending unit.
Was this
answer
helpful?
Yes
No
+4
Tuesday, July 7th, 2020 AT 1:38 PM (Merged)
Tiny
PLUMBED1
  • MEMBER
  • 2 POSTS
  • 1987 CHEVROLET SILVERADO
  • 142,000 MILES
I am attempting to trace why I am only getting 8.4 volts to my dual tank switch on my 87 R30. I have ohmed all the fuses, checked every ground I can find, have jumpered 12 volts directly through the switch, switch connection, and both relay's and got 12 volt's to the fuel pumps, which work fine. I am currently trying to locate a fuseable link that I read about behind the gauges. Have yet to find this mystic wire. Any suggestions?
Was this
answer
helpful?
Yes
No
+1
Tuesday, July 7th, 2020 AT 1:38 PM (Merged)
Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
Most fusible links on that year are attached to the starter under the manifold. If you rlinks were bad it could cause this but it almost sounds like a wire is grounding out partially. The pink wire leads to the fuse box off of the ign switch. See diagrams
Images (Click to make bigger)
Thumb
Thumb
Was this
answer
helpful?
Yes
No
+2
Tuesday, July 7th, 2020 AT 1:38 PM (Merged)
Tiny
PLUMBED1
  • MEMBER
  • 2 POSTS
Thank-you for the response. If I find the problem based on your advice I assure you that I will make a donation to this web site. You are the only one out of ten responses from other sites that have made any sense. I will be sure to let you know the results.

Dan
Was this
answer
helpful?
Yes
No
+1
Tuesday, July 7th, 2020 AT 1:38 PM (Merged)
Tiny
LOBOONE
  • MEMBER
  • 2 POSTS
  • CHEVROLET SILVERADO
I changed my fuel pump a year ago and it went bad again about a month ago. I have since had intermittent problems with it. Now it won't work at all. I have checked my relay and it is getting voltage. My fuel gauge jumps all the way to the right and then back to the left when I turn the key on. It then settles down. When I installed the new pump it had different colored wires than the other one and I think I have it wired right but is it possible that I have connected a ground incorrectly? Thank you very much.
This is a 1998 Chevrolet silverado 5.0 L 2wd
Was this
answer
helpful?
Yes
No
Tuesday, July 7th, 2020 AT 1:38 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
The fuel pump gets its power from the gray wire the black is ground.

The fuel pump relay only works for 2 secs. and its energize by the computer

below is the fuel circuitry


https://www.2carpros.com/forum/automotive_pictures/12900_pump_wiring_1.jpg




https://www.2carpros.com/forum/automotive_pictures/12900_oil_sending_unit_and_fuel_pump_circuit_19.gif



www.eautorepair.net
Was this
answer
helpful?
Yes
No
+1
Tuesday, July 7th, 2020 AT 1:38 PM (Merged)
Tiny
MRVASQUEZ
  • MEMBER
  • 2 POSTS
  • 1987 CHEVROLET SILVERADO
  • V8
  • 2WD
  • AUTOMATIC
  • 145,000 MILES
I need help. Fuel pump not working, replaced filter, fuel pump, relay and still will not pump. Can some one help?
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Tuesday, July 7th, 2020 AT 1:42 PM (Merged)
Tiny
BLUELIGHTNIN6
  • MECHANIC
  • 16,542 POSTS
Check fuse for fuel pump circuit, is voltage getting to the relay?
Was this
answer
helpful?
Yes
No
Tuesday, July 7th, 2020 AT 1:42 PM (Merged)
Tiny
MRVASQUEZ
  • MEMBER
  • 2 POSTS
Fuse was burnt and replaced but no power. Does the switching valve have anything to do with the pump getting voltage? Tank switch RH LH was burnt as well. Could the ECM gone bad? Wired the pump directly to the battery and pump worked truck turned on. What else can I trouble shoot.

1. Could it be the ECM.
2. Voltage at switch valve fluctuates between 2 an 8 volts.

HELP? TRUCK is CLassic
Was this
answer
helpful?
Yes
No
+1
Tuesday, July 7th, 2020 AT 1:42 PM (Merged)
Tiny
BLUELIGHTNIN6
  • MECHANIC
  • 16,542 POSTS
Must be getting too much voltage on system then to have popped the fuse and the switch. Yes it could be caused by a failing ECM. May also be the oil pressure switch, the fuel pump circuit runs through the oil switch as safety measures. Does the oil pressure gauge work?
Was this
answer
helpful?
Yes
No
+2
Tuesday, July 7th, 2020 AT 1:42 PM (Merged)
Tiny
WOLFE1
  • MEMBER
  • 5 POSTS
  • 1987 CHEVROLET SILVERADO
Electrical problem
1987 Chevy Silverado V8 Two Wheel Drive Automatic

the fuel pump relay has been changed and the switchvalve under has been changed could it be the switch in the cab. I got it started and it run for about 10 minutes then cut off and wouldn, t start backup.
Was this
answer
helpful?
Yes
No
Tuesday, July 7th, 2020 AT 1:42 PM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,762 POSTS
Have you run battery power and ground directly to the fuel pump to determine if the pump is good?
Was this
answer
helpful?
Yes
No
-1
Tuesday, July 7th, 2020 AT 1:42 PM (Merged)
Tiny
WOLFE1
  • MEMBER
  • 5 POSTS
The pumps are good 0ne is new, when it ran ran for 10 minutes it ran at a high idle but both pumps worked and then cut off and wouldn, t start back up, like no power was getting to the pumps.
Was this
answer
helpful?
Yes
No
Tuesday, July 7th, 2020 AT 1:42 PM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,762 POSTS
I'll ask you again. Since your problem re-occurred, have you tested the pump by powering it manually?

If not, you need to do that before going any further. Also see if it will run when you do that.
Was this
answer
helpful?
Yes
No
+1
Tuesday, July 7th, 2020 AT 1:42 PM (Merged)
Tiny
WOLFE1
  • MEMBER
  • 5 POSTS
I haveen, t are you saying run a wire from the battery to the fuel pump connector.
Was this
answer
helpful?
Yes
No
Tuesday, July 7th, 2020 AT 1:42 PM (Merged)

Please login or register to post a reply.

Related Fuel System Fuel Pump Relay Content

Replace Your Fuel Pump Relay - Easy Steps
VIDEO
Replace Your Fuel Pump Relay - Easy Steps
Instructional repair video
VIEW MORE

Sponsored links