LBZ: Gotta fuel pressure gauge question

[Snichols243]

i recently put gauges in my truck boost pyro and fuel pressure the boost and pyro work good, but the fuel pressure..... i know people say you wont read anything at all if you dont have a lift pump... i have a raptor lift pump (came on the truck). when i had the wires disconnected from the sending unit the gauge read max pressure 30psi but after my adapter came in and i hooked the sending unit up, the guage doesnt read anything, n i can hear the raptor running. any one have any ideas ? could the raptor not be working right or the sending unit for the gauge not be working??

Thanks

 

[rgullett83]

What brand of gauges? Is the primer hard with the lift pump running, if so then the pump is working and you have fuel pressure. Double check all your wiring for the fuel psi gauge to make sure it's wired correctly.

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[Snichols243]

its a glowshift gauge, i havnt tried the primer with the truck on but ill have to do that tomorrow

 

[JoshH]

Where did you put the sending unit?

 

[rgullett83]

I don't want to be a Debbie downer, but my experience with gloshift gauges has not been good, they are cheap, but in my opinion very low quality.

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[Snichols243]

Ya I kinda got that feeling when I was installing them , they look soo good though. Lol. But this morning I turned the key could hear the pump running and I could push on the primer but idk what its like without the pump on

I mounted the sending unit in the bleeder port on top or the fuel filter

 

[bluecollar]

My brother got 3 sending units from them never could get it to work. Never a problem with boost and egt tho.

 

[rgullett83]

Do you know anyone that has a vacuum/pressure gauge to hook onto the factory test port, to check psi with?

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[rgullett83]

Also you could turn the key on so the gauges are powered up, and have someone watch it while you pump the primer to see if it builds pressure

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[JoshH]

Also you could turn the key on so the gauges are powered up, and have someone watch it while you pump the primer to see if it builds pressure

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That's what I was about to suggest. If you pump the primer on top of the fuel filter, it will build a lot of pressure. I can max out my 15 psi gauge doing that. It should hold long enough for you to walk around to the gauge.

 

[Snichols243]

Well this morning I pumped it once, not knowing if I was going to mess something up ,but when I closed the hood and got back to the truck the gauge still read 0 so tonight ill have someone get in the truck and see if pumping the primer makes the gauge change , and i think i may have access to a gauge to read the pressure.
So my two problems prolly one gauge/sending unit isn't working. Or two the Esprit isn't working right and the truck is running like it does without a lift pump.
Idk if this have anything to do with anything but my whole reason for gauges is that when I'm dam near at full throttle the truck throws a low fuel rail pressure code , the truck came with a tune in the computer guess it used to have efi live but the dsp 5 has been cut out.
Thanks for the help guys. I'll have to do some playin tonight see what I can figure out.

 

[Duraskank]

It did have a dsp5 setup from rob in it and a cts insight for gauges. When I sold it the new owner had it tuned again at scheids and put the lift pump on it I assume cause I never did. He tried to tell me it was never tuned in the first place and whined around about the cost to tune it again cause he didn't have my v2. So at least you know a little about it now

He talked about building the tranny and a bunch of other bs but I saw it on a car lot in MO, where you prob found it lol.

Can't believe he basically sold everything off it that I did....smh.

 

[Snichols243]

So you used to own my truck ? Small world. Haha ya I'm trying to get the fuel pressure deal figured out then I wanna try and tune it again. Mainly because idk what it has in it now , and this is the first dmax I have ever been around. I also got an old 12v cummins

 

[Duraskank]

Yeah I bought it in Guthrie, Oklahoma from a dealership my buddy owns. Here's what it looked like when I got it:

And here's how I sold it:

 

[jnieberlein]

Sounds like the FPRV is popping off at wide open throttle, for the original owner was the FPRV ever shimmed? your lift pump nor your gauge is going to help with this problem. need to check if you are losing rail pressure w/ tech 2 or a EFI

 

[Duraskank]

Never shimmed. It was basically stock with tunes when I sold it.

 

[Snichols243]

dang the guy i bought it from stripped it didnt he! it was a dam good lookin truck when you sold it! but the guy that had it before me says it has a shim kit, and i have one sitting in my console but sence he told me there is already one in it i dont want to break it open to see, n i dont know if i should believe what the other guy has to say.

 

[Duraskank]

I wouldn't take his word for anything. Only way to know is find out for yourself.

 

[greif03lb7]

Plus if he did shim it he probably only used two shims not three. Get efi and tune it out so it cant throw that code and limp. Mine would still throw the low rail psi at wot after I shimmed it. You can do the bottle test also.

 

[Snichols243]

ya thats what im thinking, do you think its the tune thats in it is what is causing the code? if it is shimmed , and it still isnt cutting it, should i try a race fuel valve http://www.xtremediesel.com/xdpracefuelvalve.aspx says to stop the p1039 code but ive heard their hard on injectors and thats the last thing i wanna buy for this truck