I drove about 5 miles and then I lost power, no fuel flow. Let it cool down for 15 min or so and its good for another 5 or 6 miles then repeat. I added a new ground and no go. If I hook a 9 volt to the fuel pump it will run constantly but when using the key it doesnt always turn the pump on. I put a new fuel filter on right before the pump. Should I get fuel to the rail using the 9V battery to run the pump, because I'm not? Any ideas?
This is a problem with my cj, Fuel Injected 4.2L I6.
No Fuel Pressure
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Tin Medic
Topic author - Posts: 529
- Joined: Sat Aug 27, 2011 12:48 pm
- Location: Ft. Carson, CO
No Fuel Pressure
89 GW 360/727/208 (soon to be LQ9/727/208) MSD 8523 Pro Billet Distributor, MSD 8207 Blaster SS Coil, 30x9.5x15 Destination M/Ts, Warn Lock Out Hubs
"I don't always downshift, but when I do its next to a Prius so the driver can hear me hurt the environment."
Jeeps don't break down, they're just extremely demanding when they need parts replaced!
Jeep Owner
"I don't always downshift, but when I do its next to a Prius so the driver can hear me hurt the environment."
Jeeps don't break down, they're just extremely demanding when they need parts replaced!
Jeep Owner
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AwesomeJ10
- Posts: 3031
- Joined: Sat Aug 27, 2011 10:26 am
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Re: No Fuel Pressure
I dunno if 9v is enough to push a TBI fuel pump, but I kinda doubt it.
How are the fuel filters? You should have one between the tank and the pump, then another between the pump and the TBI. That's how I run my rigs with no issues.
When you turn the key on a GM TBI system, the fuel pump relay should be energized by the ECM. The relay will then energize the fuel pump itself. Should be 12V + There is a fuse somewhere near the fuel pump relay along the harness. Check that.
How are the fuel filters? You should have one between the tank and the pump, then another between the pump and the TBI. That's how I run my rigs with no issues.
When you turn the key on a GM TBI system, the fuel pump relay should be energized by the ECM. The relay will then energize the fuel pump itself. Should be 12V + There is a fuse somewhere near the fuel pump relay along the harness. Check that.
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Tin Medic
Topic author - Posts: 529
- Joined: Sat Aug 27, 2011 12:48 pm
- Location: Ft. Carson, CO
Re: No Fuel Pressure
I didn't think a 9V would push fuel, just used it to verify the pump was working.
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Sent from my iPhone using Tapatalk 2
89 GW 360/727/208 (soon to be LQ9/727/208) MSD 8523 Pro Billet Distributor, MSD 8207 Blaster SS Coil, 30x9.5x15 Destination M/Ts, Warn Lock Out Hubs
"I don't always downshift, but when I do its next to a Prius so the driver can hear me hurt the environment."
Jeeps don't break down, they're just extremely demanding when they need parts replaced!
Jeep Owner
"I don't always downshift, but when I do its next to a Prius so the driver can hear me hurt the environment."
Jeeps don't break down, they're just extremely demanding when they need parts replaced!
Jeep Owner
-
AwesomeJ10
- Posts: 3031
- Joined: Sat Aug 27, 2011 10:26 am
- Location: Off the grid on Storm Mountain Colorado
- Contact:
Re: No Fuel Pressure
fuel pumps do get hot and go bad....
Squirt some water on it and see if that helps cool it down and make it work...
Squirt some water on it and see if that helps cool it down and make it work...
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Tin Medic
Topic author - Posts: 529
- Joined: Sat Aug 27, 2011 12:48 pm
- Location: Ft. Carson, CO
Re: No Fuel Pressure
Can the relay work intermittently? I am looking at electrical being part of the problem.
89 GW 360/727/208 (soon to be LQ9/727/208) MSD 8523 Pro Billet Distributor, MSD 8207 Blaster SS Coil, 30x9.5x15 Destination M/Ts, Warn Lock Out Hubs
"I don't always downshift, but when I do its next to a Prius so the driver can hear me hurt the environment."
Jeeps don't break down, they're just extremely demanding when they need parts replaced!
Jeep Owner
"I don't always downshift, but when I do its next to a Prius so the driver can hear me hurt the environment."
Jeeps don't break down, they're just extremely demanding when they need parts replaced!
Jeep Owner
-
AwesomeJ10
- Posts: 3031
- Joined: Sat Aug 27, 2011 10:26 am
- Location: Off the grid on Storm Mountain Colorado
- Contact:
Re: No Fuel Pressure
Sure, relay can become partially stuck and partially working. You should be carrying a couple of spare relays.... Swap it out.