Not enough fuel pressure to FPR

Whizbang · 09-21-2008, 09:34 AM

so i have start hunting into why my carb is seeing no fuel. Back checked everything and found that the line running TO the FPR has little pressure / volume. If you hold the hose up, it can barely even flow out. The pump is running, but it seems like i should be getting much more fuel than whats is cranking out.

The pump is a Carter, not sure what model. Is there adjustments on these pumps? There is no restrictions in the system from what i can tell. Purhaps something intake is no longer funcational?

Sterling · 09-21-2008, 10:44 AM

Is your filter set up correctly, before the fuel pump?
A fuel pump can be destroyed by rust chips.

Have you tested at the pump to rule out blockage between the pump and regulator/carb?
And is your tank breathing correctly? (Do you get a strong "whoosh" when you open the gas cap?)

Whizbang · 09-21-2008, 10:56 AM

the filter is before the pump. The pump WAS a known working used pump but i wont rule out that its been damaged before i installed it. Car has not run on the pump. The vent lines are open to air. I didnt have any "whoosh" when i opened the gas cap.

I am going to have to get under the car and pull the line after the pump and see how the flow is.

Rogue_Wulff · 09-22-2008, 09:08 AM

Deffinately check for flow at the pump. If the pump isn't putting out much, it could be a restriction in the line coming from the tank. If the car has sat for any length of time, the pickup tube could be clogged. That's always a fun job on S1/S2 cars, due to the lack of a removable assembly.

Whizbang · 09-22-2008, 09:25 AM

the thing is, its hard to say whether or not the pump is shot without checking the tank...

maybe i could just get a gas tank, have a tube from it to the pump, the from the pump to another can and see what its flowing

BigTeddy · 11-20-2008, 06:00 PM

Main problem with not getting a good reading on the reg's is sometimes he/she run to big of return line on the fuel...which is not allowing the fuel press reg read correctly...In that instance fuel is just flowing to from and back from the tank however it feels with no built up pressure....

On my setup with the racing beat intake mani and holley 600 i don't have a return...there is no need...press reads fine and is set at the desire i want it and the carb will only take what it wants either way...So all in all its a win win situation

BigTeddy · 11-20-2008, 06:01 PM

Quote:

Originally Posted by Low Impedance

the thing is, its hard to say whether or not the pump is shot without checking the tank...

maybe i could just get a gas tank, have a tube from it to the pump, the from the pump to another can and see what its flowing

Yes that is a good way to check if the pump is working correctly...Also what size return line you have...in most cases a return line is not needed if the reg is set to the correct fuel press...

As mentioned before i myself im not running a return...

09-21-2008, 09:34 AM	#1
Whizbang Respecognize! Join Date: Jul 2008 Location: Δx = ħ/2Δp iTrader: (5) Posts: 3,190 Rep Power: 20	Not enough fuel pressure to FPR so i have start hunting into why my carb is seeing no fuel. Back checked everything and found that the line running TO the FPR has little pressure / volume. If you hold the hose up, it can barely even flow out. The pump is running, but it seems like i should be getting much more fuel than whats is cranking out. The pump is a Carter, not sure what model. Is there adjustments on these pumps? There is no restrictions in the system from what i can tell. Purhaps something intake is no longer funcational? __________________ For current updates and event coverage check out Follow on Twitter! @WhizbangRally Whizbang Rally's Webpage \| Facebook

09-21-2008, 10:56 AM	#3
Whizbang Respecognize! Join Date: Jul 2008 Location: Δx = ħ/2Δp iTrader: (5) Posts: 3,190 Rep Power: 20	the filter is before the pump. The pump WAS a known working used pump but i wont rule out that its been damaged before i installed it. Car has not run on the pump. The vent lines are open to air. I didnt have any "whoosh" when i opened the gas cap. I am going to have to get under the car and pull the line after the pump and see how the flow is. __________________ For current updates and event coverage check out Follow on Twitter! @WhizbangRally Whizbang Rally's Webpage \| Facebook

09-22-2008, 09:25 AM	#5
Whizbang Respecognize! Join Date: Jul 2008 Location: Δx = ħ/2Δp iTrader: (5) Posts: 3,190 Rep Power: 20	the thing is, its hard to say whether or not the pump is shot without checking the tank... maybe i could just get a gas tank, have a tube from it to the pump, the from the pump to another can and see what its flowing __________________ For current updates and event coverage check out Follow on Twitter! @WhizbangRally Whizbang Rally's Webpage \| Facebook

11-20-2008, 06:00 PM	#6
BigTeddy Rotary Fan in Training Join Date: Sep 2008 iTrader: (0) Posts: 46 Rep Power: 0	Main problem with not getting a good reading on the reg's is sometimes he/she run to big of return line on the fuel...which is not allowing the fuel press reg read correctly...In that instance fuel is just flowing to from and back from the tank however it feels with no built up pressure.... On my setup with the racing beat intake mani and holley 600 i don't have a return...there is no need...press reads fine and is set at the desire i want it and the carb will only take what it wants either way...So all in all its a win win situation __________________ One Turbo At A Time

09-21-2008, 10:44 AM	#2
Sterling Premium Vendor Join Date: Feb 2008 iTrader: (2) Posts: 74 Rep Power: 17	Is your filter set up correctly, before the fuel pump? A fuel pump can be destroyed by rust chips. Have you tested at the pump to rule out blockage between the pump and regulator/carb? And is your tank breathing correctly? (Do you get a strong "whoosh" when you open the gas cap?)

09-22-2008, 09:08 AM	#4
Rogue_Wulff Non Member Join Date: Jun 2008 iTrader: (0) Posts: 310 Rep Power: 17	Deffinately check for flow at the pump. If the pump isn't putting out much, it could be a restriction in the line coming from the tank. If the car has sat for any length of time, the pickup tube could be clogged. That's always a fun job on S1/S2 cars, due to the lack of a removable assembly.