Mule Skinner

My guage went to zero and I felt pretty confident that whatever the problem, it was not that serious, installed a temporary mechanical guage and discovered pressure was at 25 lbs. So in cab guage or sending unit is bad, easy enough to fix. In cab guage only went up to 16 lbs so I have been way up over that. I adjusted regulator down to 17 lbs at idle. Was wondering however, I have been having some hard to start issues lately and am curious of the ideal range for fuel pressure to start truck? I recall seeing here several years ago too much pressure can lead to hard to start issues.

Thanks for any input.

RowJ

With good VP-44, I would say 14-25 psi. Does your Holly Blue 'bump' to start or run continuously with key on?
I have had two different springs in my FASS....14 psi and 19 psi. Both started instantly at all times.

RJ

Shovelhead

< 20 psi is usually prefered.

Some have found that > 20 psi will experience Hard To Start problems.

Mule Skinner

The Holley is wired w/ key on so it runs all the time. Thought about wiring so Holley only runs when engine runs but I still have factory LP in place and figured if and when it goes bad I still have Holley pushing/priming fuel to IP to get truck started.
I set pressure down to 15 and seems start better. Will continue to monitor and hopefully this all the problem was.

high bid

The psi recommended above is good. With the higher psi you run the risk of the fuel filter canister leaking from around the seals. I don't think it was designed to handle high psi. I was running about 25-30psi w/no hard start problems and my canister begain leaking again. I installed the holley regulator that came w/the pump and now no problems running @ 19Idle/16WOT.

RowJ

I have been having some hard to start issues lately ...........
The Holley is wired w/ key on so it runs all the time

I think you may have answered your own question!

RJ

thumper549

I do not know nothing and can prove it!
But I have read and read and read
This has been the consumes
The VP is not using all that is sent to it (DUUH )
The VP uses the rest for lubrication and cooling itself
So in stock form,4 to 5 lbs would be the minimum ( The absolute minimum)
Somewhere around 10 lbs then you have at least 2 x as much going through the pump and back to tank.
You can up the pressure more but at some pt. there are diminishing returns (LOL) as you can only move so much through a given hole at a given pressure.
In other words, you might have more pressure but no more volume.
If the pump has more going to it then being used..it probably as happy as a VP can be...