fuel pressure

[tanner_pimp101]

I just put in a walbro 255 fuel pump and a Aeromotive fuel pressure regulater and I need to know what psi my fuel should be set at with the vacuum line off?? I still have stock injectors, afm, and turbo.

 

[10secdream]

I just put in a walbro 255 fuel pump and a Aeromotive fuel pressure regulater and I need to know what psi my fuel should be set at with the vacuum line off?? I still have stock injectors, afm, and turbo.

43psi.

 

[tanner_pimp101]

43psi.

thank you so much, I had it at 25

 

[grimreaper]

33-40 psi...

 

[jdub]

33-40 psi vac off
23-30 psi vac on

Both have to be in range at idle.

Tanner - if you've installed a Walbro, you either need to drill the J tube out or eliminate it.

10sec - This is the Tech Section...if you are not 100% sure, do not post.

 

[tanner_pimp101]

33-40 psi vac off
23-30 psi vac on

Both have to be in range at idle.

Tanner - if you've installed a Walbro, you either need to drill the J tube out or eliminate it.

10sec - This is the Tech Section...if you are not 100% sure, do not post.

I did, I have an aftermarket block off plate from DRIFTMOTION.

 

[mk3dude]

33-40 psi vac off
23-30 psi vac on

Both have to be in range at idle.

Tanner - if you've installed a Walbro, you either need to drill the J tube out or eliminate it.

10sec - This is the Tech Section...if you are not 100% sure, do not post.

I was wondering my fuel pressure at idle with vac off is around 40psi but when i do connect the vac the pressure drops only to around 35psi. is this normal? I am running stock injectors as well as fuel pump.

Thanks

 

[jdub]

It's not normal...pressure should drop into the "vac on" range I posted. Did you drill out or remove the J tube?

 

[mk3dude]

The J tube is in the same location nothing has been drilled out. but it has been by passed im running the return line straight. would not drilling out the j tube cause the weird vacume?

 

[jdub]

Ok, I'm confused...is the line from the FPR connected to the J tube?

 

[mk3dude]

no its not. the j tube is still there but there is no line running to it.

 

[jdub]

I guess there's no way the J tube can affect fuel pressure then

Is this a stock FRP as well? If not, exactly what kind? (is it a Chinese copy)

 

[mk3dude]

hmmm This is an aftermarket one sx performance its not a china copy.

 

[jdub]

Not familiar with that one. I was actually referring to the Aeromotive knockoffs you see sold on eBay...the diaphragm is crap, but you can fix it by ordering an Aeromotive replacement from Summit.

It sounds like the SX one you have is not giving you the proper drop...maybe someone will chime in that has one. Meanwhile, I would lower the vac off FP to 33-35 so it will put you in the correct range vac on.

 

[mk3dude]

ok I will try that thank you for your help.

 

[AndyMac]

sx regulators are a very high end product so I doubt quality is the issue.

they are however probably aimed at a fuel system that is pushing more pressure than what 1 walbro 255 is pushing.

do you have any vac problems when on idle? (low vac)

 

[mk3dude]

No issues on idle boost gauge shows 20 vac. could it be that my gauge on the regulator is not calibrated properly? the gauge is a def con gauge. did not have much faith in it when i got it in the first place. but i could not say no to free :nono: