Engine/Transmission (1998.5 - 2002) need help with fuel pressure gauge

[Dodge5256]

i installed my fuel pressure gauge yester day and i need some help finguring out why it is not working propory. it is a the DI-PRICOL fuel pressure gauge it is hooked up to the line runing from the stock fuel filter to the injector pump using a taped banjo fiting at fuel fuel filter. what it is doing for the most part it when i prine it gauge jumps up to 15psi and then slowly dropes down to 0. when i stat the truck is jumps back up to 15 psi. if i rev the engine hard it will act nornaly somtimes but other time it will drop to 5 psi as if u just lost the pressure sundeny. one at 5 psi if i rev the truck jentlay it will mimic what the pressure that u would expect to see exept minus 10psi if i rev the engine hard a few more times it will suddeny jump back to reading aroung 15psi. iv tryied bleading as much air out for the gauge as i can but that didnt help at all. any ideas on what i should do?

 

[AKAMAC]

Sounds like the LP is failing. The drop to 0 psi after priming is normal. The -10 psi is the VP44 pulling fuel all by itself (not good). Mike

 

[Dodge5256]

Sounds like the LP is failing. The drop to 0 psi after priming is normal. The -10 psi is the VP44 pulling fuel all by itself (not good). Mike

i just got a new injector pump a week a go and when the dealer installed the new injector pump the tested out the lift pump and that sad it was working just fine. granted this is the dealer saying it, so im going to check it out, i an planing on geting a fass pusher pump in a month of so. the dealer doesnt sell LP anymore they jsut have kits that replave the LP with a carter pump that mounts in the fuel take for 1K. where would be a good place to get a replace ment LP for cheep, i only need it to last long enough untill i can get a pusher pump installed.

 

[Holysmokes]

forgive my stupid question but...

What happens (reading on guage) when you turn truck off?

 

[Graphic man]

try bleeding the air out of the line, start the truck and crack the line at the gage.



see if that helps





Scott

 

[AKAMAC]

http://www.hoeslidiesel.com/specials.htm



At 139. 95 w/pigtail, not a bad deal. They will ship next day air.

 

[Dodge5256]

What happens (reading on guage) when you turn truck off?

usaly it reads 0 but lastnight aver driving the truck around the reading was 5psi

 

[Dodge5256]

ok, i just got back and when i pulled into the parking lot the gauge droped to 5psi and sayed there, when i shutdown the engine it didnot move at all, it sayed at 5 psi. i have noidea what this is all about. could it be caused by air in the system or maybe the coolant expanding because of heat?

 

[EDembowski]

Sounds like the isolator, I had the same problem with mine. I installed a gauge directly onto the filter housing, so I could compare it. Finally I got rid of the isolator, some wouldn't recommend it, but I ran a 6' SS braided line from the fuel filter housing directly to the gauge. Now I have an accurate reading.

 

[Dodge5256]

Sounds like the isolator, I had the same problem with mine. I installed a gauge directly onto the filter housing, so I could compare it. Finally I got rid of the isolator, some wouldn't recommend it, but I ran a 6' SS braided line from the fuel filter housing directly to the gauge. Now I have an accurate reading.

i dont think i would ever run the gauge with out the isolator, would meen bringing fuel into the cab, something that im not willing to do. i dont see how i could be the isolator, it just seems to simple to have problems so soon.

 

[Holysmokes]

Im in agreeance with them about the isolator. Thats why I asked. I lost my isolator (2 months old #@$%! ) and when I shut it off I kept almost 6psi. The place I bought it said "Yea,we have gotten about 40% of those back" . No they wouldn't cover it in warranty ( because they no longer deal with that Isolator co. ) This happened to be the "cylinder" style isolator and I've switched to the "pancake" style.

Just wondering... . what type do you have?

 

[Dodge5256]

Im in agreeance with them about the isolator. Thats why I asked. I lost my isolator (2 months old #@$%! ) and when I shut it off I kept almost 6psi. The place I bought it said "Yea,we have gotten about 40% of those back" . No they wouldn't cover it in warranty ( because they no longer deal with that Isolator co. ) This happened to be the "cylinder" style isolator and I've switched to the "pancake" style.

Just wondering... . what type do you have?

I have the "pancake" style isolator

 

[Holysmokes]

Ill tell ya what Im going to do. I use a pancake isolator now but I use the clear plastic line with antifreeze. Im switching to a braded stainless steel line with antifreeze. I believe I have a small leak. (easy to do with the fittings they provide) I have used the syringe and filled,and filled,and filled. About 3 weeks later I end up with a pretty good air pocket.

 

[EDembowski]

Put a direct reading gauge on the filter housing, you can get a relatively inexpensive one from Summit Racing. That will at the very least give you something to compare your readings with.