How 2 test fuel pressure reg?

[SpeeednV6]

Well, I changed out my corroded fuel line today. I replaced it with fuel injection hose. Anyhow, I decided to try out the new alchy system and was popping at around 10psi to 18psi. I could run 18pis w/o knock w/o alcy before. I am certain it is not the alchy causing problems. O2's were low 800's. F/P did go up with boost. I took her home and as soon as I took out the key, the f/p went down pretty quickly. I did not see any leaks. I am wondering if my gauge is off or my pump or reg. is faulty? Can I test the regulator with a vacuum gauge? I did close off the supply holes with my fingers and the reg. will not hold vacuum. This is with reg. off, of course.

 

[Just a Six??]

If it's an Accufab style adjustable regulator then just remove the 6 screws & take off the top. The only thing you can check is if the diaphram is torn or damaged. They sell repair kits but thats all thats included. Not very often the diaphram will tear but it has happened.

 

[SpeeednV6]

It's a 237 regulator.

 

[RmvBfrFlght]

It's a 237 regulator.

The vacuum port should hold vacuum on the stock regulator. If not then the diaphragm may be leaking or the case seam is.

An adjustable FPR doesn't always hold a good vacuum over time. The adjuster threads can leak a smidge.

RemoveBeforeFlight

 

[SpeeednV6]

I tested the stock 237 regulator. It does hold vacuum. That seems that it's my pump that isn't holding fuel pressure. My adjustable f/p reg. does not hold vacuum very well. Does this mean that it is bad?

 

[groumoutis]

Are you sure you don't have a leaking injector? When I still had the original injectors in my car it wouldn't hold pressure but when I put in the new injectors it would hold pressure.

 

[RmvBfrFlght]

I tested the stock 237 regulator. It does hold vacuum. That seems that it's my pump that isn't holding fuel pressure. My adjustable f/p reg. does not hold vacuum very well. Does this mean that it is bad?

I'd say that the 237 regulator is OK. As for the adjustable FPR, it may be leaking past the adjuster threads. That is common.

RemoveBeforeFlight

 

[SpeeednV6]

Injectors are brand new from Racetronix. Adjustable FPR leak common? Is this o.k. to use? All sparkplugs look the same, brownish tips.

 

[ALVAROG1983]

I would look at the pump

 

[87GN_70GS]

Put air pressure on the top of the regulator. Add whatever air pressure plus your base fuel pressure and see that it tracks with the added air pressure.