I dont use an isolator like many others on the board...Recently my fp gauge has been jerky and it buzzes. Its only about 3 mos old...is it broken or should I just install an isolator?

 

Do you have a t handle shut off valve in the pressure line and only open it a1/2 to 3/4 turns because the vp sends out pulsesin the pressure. That will help dampen them and might be your fix.

 

no I dont. Where can I get one?

 

NAPA or an industrial supply store....try putting a "needle valve" between the guage and fuel filter and see if it helps. You may need a new guage.

 

I ordered a new gauge and isolater last week from Geno's.
I spoke to Andy at Geno's about my "pulsating--chattering fuel pressure gauge" and this is what he said.

The isolater i have is a gold colored cigar shaped unit about 6" long. He tells me that at one time they used this isolater and had so many problems caused by it that they switched to what they have now witch is a disk shaped isolaer.
he said that if i had (and i had ) removed the isolater from the loop trying to correct the problem, that diesel fuil going directly to the gauge could destroy the gauge itself.

expect new stuff first of week , hope this is finnally the answer

 

It's not just the VP-- the LP itself pulses quite badly.

 

I have run a FP guage with no isolator for over 3 years now. It's diesel direct to the guage on the dash. I have the needle valve also as well as using a grease gun hose as a buffer.

About every 5 or 6 months, mine will start to buzz and the needle itself will "wiggle" ever so slightly. All I do is shut off the needle valve and disconnect the line from it to the guage. I just let it sit there for a few minutes and let it "drain" per say. Hook it all back up and it is good to go for another 5 or 6 months.

Not exactly sure why it does this but I have noticed that when I'm playing hard with the truck and pull the FP down a bunch of times, it will buzz sooner than normal. I have a feeling that there is a buffer of air in the line when it is initially hooked up and subsequence "pulls" on the fuel pressure changes this arrangement somehow.

I believe it was Haulin in Dixie that mentioned to run the guage fuel line as high as possible on the firewall before entering the cab to make kind of a loop in the line. I did this and it did make a big difference in the intervals between buzzing.

Not sure if it will help you but thought I'd pass it along.

Jeff

 

herb,

I too will verify what the folks at Geno's said. In fact most gauge manufacturers will void the gauge warranty if they smell diesel in the gauge. We sold the cylindrical isolators for approx 3 weeks and they started to fail almost immediately, we have been using the flat pancake style ever since with zero failures to date. It has a flourelastomer (SP) material that is diesel fuel compatible and works great, easier to mount too! Call us if you need one or have any questions etc.

Mark @ DPPI

 

Quote:

...that diesel fuel going directly to the gauge could destroy the gauge itself.

That's a total load. I challenge anyone to find a gauge that isn't compatible with diesel.
My experience with isolators on diesels is they all eventually fail internally and allow diesel to the gauge most often without the owner's knowledge. If the gauges weren't compatible with diesel you would hear a lot more complaints.

 

Mine's been compatable for nearly 1 1/2 years without an isolator. Compatable could include the pump(s) pressure pulses and a needle valve smooths those out. Of course, if the gauge breaks inside, it'll wet yer rug 'an stink up yer cab.

 

I had the same problem.. when I installed bigger lines.. I moved the the pressure port back to the outlet of the filter housing... I haven't had a problem since... I had tried using a section of rubber line going to the gauge.. but it didn't help... The plastic (SS braided line) could also be helping to dampen the vibration....
Bryan

(No isolator over 4yrs.. no problems)

 

I have tried isolators..and no isolators and now I have the needle valve that is barely cracked open.
The best solution that I have found is ....dropping that lp in a deep river somewhere. Since I installed the FASS system ...I have had NO issues with the gauge buzzing or making enough noise to louder than the motor.
There is soooooooooooooo much pulsation coming from that lp that it just beats the gauge silly.
Other than changing the lp out for something else.. a needle valve would cure your problem.

Rick

 

what is your www ?