Fuel Pressure Testing

[Aso544]

Trying to find on my setup how to attach a fuel pressure gauge to test my fuel pressure. I suspect the current permanent one may be false. Can find a valve to attach one to.

 

[Pronto]

Unscrew that old pressure gauge off and screw the fp tester into that brass angle fitting. You may need a fitting to do that if your kit didn't come with adapters.

 

[Buckshot G/N]

Is your car running well,accelerating properly. Like the previous post said unscrew old gauge an plug pressure gauge into the fuel rail.

 

[Aso544]

my Car went from running perfect to leaning out on top end causing knock. My alky Kit is function fine and set on 6 and I tested it to make sure it was operating. I even dialed my boost way back but still getting too end knock. I made no other changes to any settings. I’m thinking maybe my fuel pump might be going out so I wanted to test my FP at idle and under throttle to see what it was doing. Hoping for an easy fix.

Also.... is that fuel regulator adjustable .... if so.... how?

Thanks!!!!!

 

[salvageV6]

Unscrew that lock nut on top and put an Allen wrench in the top of the bolt and turn it.

Hose off that thing for idle adjustment, set to what your chip maker says to put it at idle, usually 43-45 psi. Then put the hose back on and zip tie it so it doesn't blow off under boost.

 

[dank GN]

Do yourself a favor and find a turbo buick guy around you and take it to him . Ask him to check over your car . There is a shredder valve in the male portion of the fuel rail so ether get the tool that’s 50 cent tool and unscrew the valve or use the adapter that the current gauge is using.

 

[Aso544]

I was hoping to test a few things to see if something simple was wrong as the closest BGN guy is about 5 hours away

 

[Royal-T-Ltd]

my Car went from running perfect to leaning out on top end causing knock. My alky Kit is function fine and set on 6 and I tested it to make sure it was operating. I even dialed my boost way back but still getting too end knock. I made no other changes to any settings. I’m thinking maybe my fuel pump might be going out so I wanted to test my FP at idle and under throttle to see what it was doing. Hoping for an easy fix.

Also.... is that fuel regulator adjustable .... if so.... how?

Thanks!!!!!

Quick question - How can you verify that your Alky system is working fine? Do you have a test kit? How old is the pump?
Also how old is your fuel pump?


Sent from my iPhone using Tapatalk Pro

 

[GNRick]

Julio sells a gauge to test the alky pressure. Does the led go from red to green at around 10 - 13 psi of boost?

 

[Aso544]

My alky pump is brand new....replaced my old one due to a small leak. I tested it using the button while at idle which makes the car stutter and start to shut off. Not sure on my fuel pump’s age but I’m guessing it’s pretty old but I did get a FP tester and her is what I discovered.

Ignition on - 35 -37 psi
Idle - 42 psi
Driving no Boost - 42-43 psi

15 psi boost - 56-58 psi. ( with the tester gauge on I actually got very few knock numbers) . I usually run 19psi of Boost but turned it down due to the knocking issue I was having. Even then the last time I drove it I was getting some 5.0-6.0 knock numbers.

3 runs from about sixty in drive (D) with no shifting

760 - 0.0
767 - 1.2
785 - 0.2

Last time I was getting substantial knock on my Scanmaster. Still has a weird on and off surge at lower speed casual driving. Once you give it some moderate throttle it goes away.

Aso544

 

[GNRick]

I had a cut out or something at around 35 mph. It went away if I gave it gas. Turned out it was the crank sensor.

 

[Pronto]

My alky pump is brand new....replaced my old one due to a small leak. I tested it using the button while at idle which makes the car stutter and start to shut off. Not sure on my fuel pump’s age but I’m guessing it’s pretty old but I did get a FP tester and her is what I discovered.

Ignition on - 35 -37 psi
Idle - 42 psi
Driving no Boost - 42-43 psi

15 psi boost - 56-58 psi. ( with the tester gauge on I actually got very few knock numbers) . I usually run 19psi of Boost but turned it down due to the knocking issue I was having. Even then the last time I drove it I was getting some 5.0-6.0 knock numbers.

3 runs from about sixty in drive (D) with no shifting

760 - 0.0
767 - 1.2
785 - 0.2

Last time I was getting substantial knock on my Scanmaster. Still has a weird on and off surge at lower speed casual driving. Once you give it some moderate throttle it goes away.

Aso544

First off, the alky tester is great tool. You can run the pump and recycle the alky to find leaks as well as a bad pump. You might have found a leak but you have more than one that the tool can help you find. Even though you have a new pump, you may have a leak at a fitting that evaporates before you can see it.
You can try raising the fp some.

 

[Zach L.]

Lots of good advice here. Just unscrew the old gauge off the rail, remove the Schrader valve if it’s still in the rail. Find an accurate fuel pressure gauge with a longer line so you can watch the fuel pressure ride with the hood shut. Those rail mounted gauges are a mixed bag- I personally wouldn’t want one sitting on the end of my fuel rail with the potential to leak or break. I use a FP tester like this:

Temporary Mount Test & Tune Fuel Pressure Gauge Kit (GM)

Test & Tune Fuel Pressure Gauge Kit (Temporary Mount) GM EFI Applications This kit allows the installer to tap into the Schrader valve outlet on the GM fuel rail and connect directly to a high-quality pressure gauge that can be custom-mounted (or temporarily mounted) within the driver's field of...

www.fullthrottlespeed.com

It’s a nice way to check fuel pressure under acceleration and when you are done and everything’s up to par, just seal the end of the rail with the S- valve and cap. Hope that helps

 

[Royal-T-Ltd]

i personally think ANYONE who owns an methanol injection system needs a test kit... something to simulate boost... not just rely on "my car stumbles when i hit the test button method"

I use it to diagnose leaky or dying pumps, use it when i make new lines to test for leaks, use it when methanol is disappearing faster than usual... its a MUST have

-aaron

 

[Pronto]

Yes! Just like having a Scanmaster is must.

 

[Chuck Leeper]

I've tested many of those small gauges. I've found that most are not accurate. However, most carry the error pretty consistently.

 

[Aso544]

How do those number look? From what I’ve read they seem correct

ASO544