need picture of adapter to take fuel pressure on 12v... so I can make one.

purchased a new pressure relief valve from cummins that goes on outlet of P pump... after less than 8k miles... it failed resulting in loss of power... stretch spring... power came right back.

now I need to measure pressure relief valve is set for.

soooo... can anyone post a picture of the adapter needed to tap into fuel system?

also considering a secondary electric pump... which one?

 

I don't have a picture of the adaptor but most of us drill out the banjo bolt at the inlet to the IP. Pull the bolt and drill down through it so that the hole is centered. After that you just tap it and thread in the fitting that comes with your gauge. If you don't want a permanent setup, you might want to do something else than I described.

 

You will NOT need an electric pump on a 12V. The stock one (if its in good shape) puts out plenty of fuel for 500+ hp. Check your fuel pressure. As was already described, pull the banjo bolt on your pump inlet and tap it 1/8" NPT, install a needle valve and run the tubing to the guage:

 

If you really put the new OF valve in the pump inlet rather than the outlet I can see why it failed.



Instructions for a fuel pressure gauge here https://www.dieseltruckresource.com/...41&postcount=9

 

opsss... pressure relieve valve is on outlet of P pump... thanks for the correction!

and thanks for all the help... I'll be yanking banjo fitting and tapping a 1/8 in NPT....

just read instructions.... very well written!

many thanks....

 

I picked up a guage to read fuel pressure and I need to get the needle valve from Grainger today. I was on their site looking at the part when I saw that they have the same need valve - but with a 90 degree elbow instead of coming straight out. It seems like this one may fit better so the line goes straight back toward the firewall instead of having to curve around? Has anyone installed the needle valve with the 90 degree bend in it?

 

A 90° valve would work just fine. There is so much room in the inlet area though that it doesn't matter much which way the line comes out.
Grainger even has 1/8" needle valves in 90° and straight that are male thread by 1/8" compression so you don't need an adaptor if you chose to use boost gauge type tubing.

 

Guys, where can I get an extra banjo bolt? You know, just in case I mess it up or to keep as a back up. I have a 96 and would assume that it's the same from 95-98.

Thanks!
JT

 

You can get spare banjo bolts directly from cummins.

 

FYI - I went to Grainger yesterday and the first needle valve I bought was the one that I thought was the 90 degree one but it had male thread on both sides - and I needed one side male and the other female to accept the 1/8 compression fitting so I bought the one that Infidel recommends. I dilled and tapped the banjo and after I installed it in the engine I had to cut a bit off of the "t" handle because it was hitting a bracket next to the banjo when I tried to turn it. All is good now - except my fuel pressure readings....

 

finally scored a spare banjo bolt .... drilled and tapped for 1/8 NPT ... needle valve, snap-on oil pressure gauge.

really stretched spring on pressure relief valve... reading 42 psi at idle, going down to 34 psi with motor revved up.

pressure is leaking down to zero after sitting. something is definitely not right. relief valve is only 6 months old... from cummins dealer. no trace of fuel leaking around fittings.

edit: found article on losing prime overnight
https://www.dieseltruckresource.com/...ad.php?t=82015

what's everyone using for a stronger spring in relief valve?

 

My fuel pressure has always dropped to zero within seconds of shutting down. I have no starting, pressure or performance problems and figure it to be normal.

 

Fuel pressure dropping to zero a few seconds after shutdown is normal. I believe that it is because of the overflow valve letting the pressure out by returning fuel to the tank.