Fuel Pressure Gauge Keeps Going Crazy

[cumminspower]

Hi Everybody.....I'm new to this forum. I found your website while I was looking for information on the web for a weatherhead needle valve for my fuel line.........Looks like a great website & forumI'm having some problems with my fuel pressure gauge...I recently installed a new ISSPRO electronic fuel pressure gauge & Vulcan universal fuel line on my truck. I have the fuel line attatched to the test port on the VP-44. Everything seemed to work fine at first after I got the gauge installed. The fuel pressure readings stayed constant (14-15psi at idle) & fairly constant when driving. After about 3 times driving the truck the fuel pressure gauge started going crazy & bouncing all around between 10psi - 20psi constantly. I pulled the sending unit off of the Vulcan fuel line & made sure to bleed all the air out of the line & put it all back together. After a couple more times driving the truck & shutting it down for an hour or so it starts doing the same thing......I'm not too sure what's going on.....It seems to have something to do with air getting in the line but I'm not sure.....Anyboody else had any problems like this after installing their fuel pressure gauges...Thanks for any help or suggestions..

[Mopar1973Man]

Sounds like the water hammer effect is finally beating the electric sender to death. You need to add that needle valve and then seat it closed and then barely crack it open again...

[cumminspower]

Sounds like the water hammer effect is finally beating the electric sender to death. You need to add that needle valve and then seat it closed and then barely crack it open again...

Thank you for the reply. I appreciate the information. I actually found your website when I was trying to find information on the 6820 Weatherhead Needle Valve. After I saw how your had your gauge setup it helped a lot. I found a place & bought one of the needle valves. Hopefully I can get it installed this weekend & it will fix the problem. I will let you know how it turns out. Thanks for the info.

[cumminspower]

Sounds like the water hammer effect is finally beating the electric sender to death. You need to add that needle valve and then seat it closed and then barely crack it open again...

The needle valve fixed the problem....I can just barely open it and get a good pressure reading. If I even open it just a little too much the gauge will start going crazy & bouncing around again though..... Thanks for the information on the needle valve....

[dorkweed]

Make sure you put a good quality needle valve in there. Lots of pressure spikes with the VP44. Might want to keep a spare. :smart

[Cummins2001]

Would a snubber valve work just as good as a needle valve? any pictures where to mount on the VP??

[Mopar1973Man]

Yes a snubber works just as good... I tend to suggest the needle valve more so for in dash mechanical gauges because of the sole fact is that with a snubber you can't shut it off if it start leaking. But with a needle valve you can shut it off and continue driving for the day or till you can get it repaired.