fuel pressure gauge/fuel rail

AJ

AJ

New member
I recently purchased a fuel pressure gauge from jegs that mounts on the fuel rail. However, after inspection realized that it did not come with a
(coupling?) to connect the 1/8 male of the gauge to the (1/4?) male on the fuel rail. After checking with the local GM dealer and jegs customer support, they were clueless to the size of the threads on the male on the fuel rail. I tried the local hardware and parts shops for the fitting, but to no avail.

Question 1: Does anyone know the size of the thread pattern on the male part of the fuel rail?

Question 2: I've looked through the jegs catolog for a fitting that would work, but could not seem to find one. Does anyone have a part # out of jegs that would work for this?

Question 3: I assume when I get the correct coupling to make this work, that I need to pull out the stem in the male part of the fuel rail to make it work.

Thanks, any help would be appreciated,

AJ
 
Loeryder

Loeryder

New member
Schrader Fitting on the fuel rail is a -4an fitting...

Thats fine for a mechanical on the rail, but really you want to be able to see if it rises with boost.
The pressure at the rail is good when your setting your base pressure, but it is just as easy to hook up a handheld gauge.

Get your self an in cab gauge and tap into the fuel line just under the cab, where the hard line turns to rubber for a foot or so. From the filter follow the feed line forward, it will hit ajunction where you can disconnect the line and install a test fitting.
Whipple Industries sells a "fuel pressure test fitting"
(there is no part number) which will allow you to install your aftermarket fuel pressure sender under the truck. The fitting (3/8 Saginaw male-3/8 Saginaw female) installs between the hardline and the fuel hose. Simple and stealthy. No ugly sender in the engine bay, no attachments to your test port and no chance of a cracked fuel rail. To order, contact Dennis @ Whipple Industries, 559.442.1261. Cost is $15.
Click to expand...
 
AJ

AJ

New member
Thanks for the responce...

Thanks for the responce...

Alex & Jas, thanks for the reply.
I had thought about an in cab F/P gauge with a sending unit, however the cost ratio of gauge and sender,( $150 Nordskog digital) and $20 for the jegs on rail seemed more resonable. My 3 pod is filled with O/P, Boost, Trans. I was not to inthralled about installing another gauge cluster in the truck, but if I did it I was going to digital (for quick glance) and placed on the shelf just right and under the ash tray. For the most part I wanted to establish and maintain my base from the Adj. F/P/R.
That's why I went with the mount on the rail gauge.
Again, thanks for the help.

AJ

P.S. If I decide to go with what I have already,
I do need to remove the stem from the shrader valve to make this work ..., correct?
 
A

apun

New member
P.S. If I decide to go with what I have already,
I do need to remove the stem from the shrader valve to make this work ..., correct?
Click to expand...

Yeah, I think so. I got a little tool from Kragen's that removes the core from inside the valve. I think my Cyberdyne FP gauge was ~$100 or so.

Alex
 
Hu Ryde

Hu Ryde

Donating Member
apun said:
Sounds like you need an 1/8" NPT to -4AN fitting. Baker Precision has these:

http://www.bakerprecision.com/adapt15.htm

They also have pre-assembled -4AN braided hoses.

Alex
Click to expand...

This unit will not mate to the rail, it will only work with this fitting if he uses a line that runs in between the rail and gauge. You will also need a -04 female straight that goes to the fitting that your talking about and then another that will go to the rail. In between these 2 strait -04 female yyou will need a line. I believe he is wanting the gauge to mount directly to the rail, like a screw on fitting.

Keith (Typhoon #1133) has this type of gauge, it was recomended to him by Daron.

http://syty.net/phpBB2/viewtopic.php?t=13498&highlight=gauge
 
0-60N4

0-60N4

Member
I have a few adaptors made up for mounting a mechanical gauge to the test port. $10.00 each. Also have some nice stainless steel, liquid filled, 1.5" dia., 0-100 psi fuel gauges in stock at $24.00 each.

Jim Longwith
Longwith's Trim & Accessories.
 
helfmann

helfmann

New member
I go with Hu Ryde's answer - I'll make a picture of a fitting and electrical sending unit tonight and post it here. I paid 45 for for mine in L.A.

M@
 
0-60N4

0-60N4

Member
Hu Ryde. Gauge and adaptor combo $32.00 + $4.00 shipping = $36.00.

I like the vac port and may want to get one later. I don't have my Ty at the moment so I don't know what fittings I would need. Nice work!

Jim
 
Hu Ryde

Hu Ryde

Donating Member
0-60N4 said:
Hu Ryde. Gauge and adaptor combo $32.00 + $4.00 shipping = $36.00.

I like the vac port and may want to get one later. I don't have my Ty at the moment so I don't know what fittings I would need. Nice work!

Jim
Click to expand...

PayPal Ok?
 
A

AndrewB

New member
Also is there an advantage of monitoring the fuel pressure ie (under the truck) before the regulator or after the regulator ie (the fuel rail)? PS I'm using a electric in the cab pressure gauge. Thanks again.
 
helfmann

helfmann

New member
More important is the fuel rail because this is what will be delivered to the engine through the injectors. As long as you have NO severe problems with low pressure (mainly caused by broken pump and old fuel filter), the rail pressure is what counts. btw I don't know about an in-line FP sensor... how do you want to measure pressure in a running liquid...throughput, OK but pressure?!?!

Just my $ 0.02

M@
 
You must log in or register to reply here.
Top