UPDATE! Boost referenced Regulator and pump Voltage ?
How do I setup the pump/line pressure test as you were saying to do?
Last edited by 30th t/a; May 3, 2026 at 06:08 PM.
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Joined: Jan 2009
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From: Bostwick, GA.
"How do I setup the pump/line pressure test as you were saying to do?"
We used a "rig" that consisted of a hanger mount, power harness with switches, a flow control valve to load the pumps, and a return line to the supply tank.
Obviously, not a 1 time deal, but safer.
Used this on the turbo Buicks we built.
In any case, I'd NEVER do such with the system in the car!
The leak at the connector hose was the most frequent offender, when a low psi issue with a new pump was encountered.
"Also, duty cycle using the hobb switch = 99%
fuel pressure using hobb switch = 64psi
Duty cycle with both pumps on all the time 82%
fuel pressure with both pumps on = 58-59psi"
At 15# boost?
Inj size?
We used a "rig" that consisted of a hanger mount, power harness with switches, a flow control valve to load the pumps, and a return line to the supply tank.
Obviously, not a 1 time deal, but safer.
Used this on the turbo Buicks we built.
In any case, I'd NEVER do such with the system in the car!
The leak at the connector hose was the most frequent offender, when a low psi issue with a new pump was encountered.
"Also, duty cycle using the hobb switch = 99%
fuel pressure using hobb switch = 64psi
Duty cycle with both pumps on all the time 82%
fuel pressure with both pumps on = 58-59psi"
At 15# boost?
Inj size?
"How do I setup the pump/line pressure test as you were saying to do?"
We used a "rig" that consisted of a hanger mount, power harness with switches, a flow control valve to load the pumps, and a return line to the supply tank.
Obviously, not a 1 time deal, but safer.
Used this on the turbo Buicks we built.
In any case, I'd NEVER do such with the system in the car!
The leak at the connector hose was the most frequent offender, when a low psi issue with a new pump was encountered.
"Also, duty cycle using the hobb switch = 99%
fuel pressure using hobb switch = 64psi
Duty cycle with both pumps on all the time 82%
fuel pressure with both pumps on = 58-59psi"
At 15# boost?
Inj size?
We used a "rig" that consisted of a hanger mount, power harness with switches, a flow control valve to load the pumps, and a return line to the supply tank.
Obviously, not a 1 time deal, but safer.
Used this on the turbo Buicks we built.
In any case, I'd NEVER do such with the system in the car!
The leak at the connector hose was the most frequent offender, when a low psi issue with a new pump was encountered.
"Also, duty cycle using the hobb switch = 99%
fuel pressure using hobb switch = 64psi
Duty cycle with both pumps on all the time 82%
fuel pressure with both pumps on = 58-59psi"
At 15# boost?
Inj size?
Running FIC 1200cc injectors.
I tried 2 different mechanical gauges off the fuel rails and one showed was 56 5psi and the other showed 55.5psi at idle while my autometer electric gauge showed 50psi.
I then out one of the mechanical gauges in to the regulator and it read 53psi.
Which location is the best for an accurate fuel pressure reading?
Last edited by 30th t/a; May 4, 2026 at 07:58 PM.
What gauge are the wires going to the fuel pumps?
I know you checked the voltage(personally I think 12.8 is way too low), but you need to do a voltage drop test on the positive and negative side.
That is going to tell you if your wiring is good enough.
I know you checked the voltage(personally I think 12.8 is way too low), but you need to do a voltage drop test on the positive and negative side.
That is going to tell you if your wiring is good enough.
