Got a bit of an issue with fuel pressure.

Usually turn ignition on and fuel pressure rises to 3.5 bar and stays there. Even if you turn ignition off it will sustain pressure for a while.

Tonight however, turned ignition on. Pressure rose as normal to 3.5 bar (while it was priming) but as soon as the fuel pump went quiet I lost all pressure. Ignition was still on and still no pressure.

Any ideas ????

Recently changed from walbro to HRC.

 

Did the car start and run, massive fuel leak, faulty gauge,

 

No fuel leak anywhere that I can see/hear/smell.
Got two gauges (incar and on reg) and both worked fine.

Car started and while running it held pressure..

 

Could be air in the pressure line as the fuel returns after priming?

 

Yea could be, I did have to cut the pressure line to fit a 't' for the incar pressure gauge.

 

There could be the problem bud, can't think of anything else it could be, hope u sort it

 

Would letting the car idle for a bit clear it ?

 

I'd guess your running a after market FPR Matt,I have this trouble as well on my Fuellab FPR but it is overnight the pressure backs off and usually takes 2 times to fire properly,I have been stratching my head over it and just give up and figured oh well as the pressure holds fine while running.

 

Just confusing because up until tonight it's held pressure on ignition.
Hoping that maybe a drive will clear the trapped air.
What pressure does your car run at Ryan ?
Also, are you using a AFR gauge ?

 

Mine runs 3.5bar with pipe off on idle mate,I have a AFR gauge to fit but not as yet mate.
Does it hold after you have phased the pump say 3 times Matt?
It should hold then,if it doesn't I would suspect faulty FPR,what make is yours?

 

SX I think off the top of my head.

I'll take it for a spin tomorrow and see if it cures it. It's gotta be a bit of air in the system as I have cut and rejoined the fuel pipe this evening. Surely a run will get the air out ?

 

My car builds the pressure up once i turn the key ON and as soon as i turn the key OFF it realises the pressure again, but i never have a problem to start the up.

 

Failed non return valve on the pump?

Don't think it's a problem, mine has never held fuel pressure if I prime the system then off the electrics. Fuelab reg BTW.