600 Fuel Pressure Gone Mad

[Cattletrkr]

About 2 weeks ago I hooked up an Autometer gauge w/iso. Used bolt from Geno's to attach directly on the inj. pump. That made it one trip and I realized why nobody puts it there. Just a little bit of vibration coming through. :-laf Moved the banjo bolt to the other end of the same fuel line, underneath the fuel filter. Worked for about 5mins and now the gauge is pegged at about 16psi and won't drop off, it's only a 15psi gauge. That was about a week ago. This afternoon the gauge did manage to drop to about 13psi when I shut the truck off. I turned the key to run position, but before I could bump the starter, the gauge shot back up to the peg. Still there. Anybody got any ideas what's going on here? Why did my lift pump run w/o bumping the starter?



If I think of it, tomorrow I'll go and double check that it's on the same fuel line as before, but off hand I think that's the only line between the filter and inj pump.



I already called autometer and they said, "send it in we'll check it out". Just thought I'd try here first. I'll probably try to bleed the gauge/iso first then... ??? There are no sharp bends or kinks in the gauge line.



I haven't had much time to check this out yet so I don't know if it's a problem with the gauge, the truck, or if I somehow managed to screw up the install (wouldn't be a first). It's not leaking, so it's kinda low on the priority list.

 

[Matt400]

I thought the lift pump was suppose to run in the key on position but would then cycle off if no rpm signal was seen.



If you want a gauge under the hood how about a remote mount using a hose to protect the gauge from vibration?

 

[rbattelle]

I thought the lift pump was suppose to run in the key on position but would then cycle off if no rpm signal was seen.

I concur.



-Ryan

 

[Cattletrkr]

Ok ,so the pump is supposed to run. That part's cool. What about the gauge going goofy? Anyone else run into this before. I double checked, I've got the right connection point as it's the only one available. Same line as the one on the inj. pump, just the other end.



Matt400, I think you misunderstood me. The gauge is on the dash, the tapped banjo bolt WAS "attached directly" to the inj. pump. I've got an isolator mounted under the hood and it vibrated all the way through that. I moved the banjo to eliminate the vibration. That part worked, now the gauge doesn't. I'm just wondering if there's something simple I'm missing.



Thanks for the replies

 

[JStieger]

Cattletrkr-



I don't have an autometer gauge like you, but I have my DiPricol plumbed into my injection pump with an isolator in between. See my reader's rig gallery. The only difference is that I installed a needle valve off the tapped banjo bolt that's cracked about 1. 5 turns to act as a "snubber". The gauge action is very smooth. I'm lucky to see 6-7 psi at idle when warm. When it's cold out or the truck is cold, the idle pressure is 4. 5 to 5 psi. At WOT, I'm down to 2. 5 psi when the truck is fully warmed up and 2 psi when "just warmed up". I will be installing a pusher pump in the near future. Not too worried yet because the truck is still seeing fuel flow to the CP3 - I just don't drive around at WOT too much anyway. Hope this helps.

 

[Jengle]

I also have mine hooked directly to a banjo bolt off of the inj. pump, same as JStieger above. Mine is also the Diprocol and runs through an isolator mounted on the firewall. I am seeing the same pressures as what he posted. I have no vibration issues and a steady needle. Also looking for a pusher pump. More Fuel!!!!!!

 

[Cattletrkr]

Problem solved...Sorta

I took the line off the back of the gauge and low and behold nothing came out. Not enough fluid between the gauge and the isolator. Gauge stayed at 13-14 psi with nothing hooked up. Put a syringe on the back and sucked the needle down to 0, went right back up to 13-14. Called Autometer and they basically said not to worry about it, it WILL be replaced. I just gotta take the whole kit back to Bumper 2 Bumper and order a new one. It's a few more hours of work and a couple weeks of screwing around waiting for another gauge, but it could be worse.



Thanks for all the replies.