Based on my readings, it would seem that I have low fuel pressure.
I tied in a gauge at the fuel supply line and these are my readings:
KEY ON:ENGINE OFF = 29 psi
ENGINE RUNNING AT IDLE. VACUUM HOSE ATTACHED TO FPR = 27 PSI
ENGINE RUNNING AT IDLE. VACUUM HOSE DETACHED FROM FPR = 27 PSI
VACUUM HOSE REATTACHED TO FPR ENGINE AT WOT = 27 PSI.
I am going to replace the fuel filter and perform another test.
The FPR looks good as there is no fuel at the vacuum hose indicating that the diaphragm is good.
I am hoping it is not the Fuel Pump.
What say you?
Haynes manual specs:
At idle:
Vacuum at FPR = 30 - 38 psi
No Vacuum at FPR = 40 - 46 psi


xj40 fuel pressure

 

Hi sanchez,

Your fuel pressure is definitely too low. Let us know if changing the fuel filter makes a difference. You might also look for any kinks in the fuel lines under the car.

Cheers,

Don

 

Replaced external fuel filter and there was no change.
Replaced fuel pump and internal filter and the problem was resolved. 40 psi.

fuel pressure at idle

 

Great job, sanchez!