been having a long standing problem with my fuel pressure gauge (mecanical with and without isolater) It is often erratic with readings anywhere from 4 lbs to 60 pounds
someone on this forum suggested using a needle valve and included a photo. i forwarded this photo to Geno's garage and this is the response i got


Good afternoon Mr. Andler,

That is not a product that we carry. I have a mechanical gauge on my truck and do not have any fuel pressure fluctuation problems. I am assuming that you have an isolator installed with the gauge? Usually fuel pressure fluctuations are caused by one of three things, there could be air in the system (I would suggest re-bleeding the lines first), the gauge may have a defect or the lift pump could actually be weak. From my personal experience, I never recommend a needle valve as they are unnecessary in my opinion. If you have any other questions or need further assistance troubleshooting please give me a call at the 800 number below as the process will be much more efficient over the phone rather than e-mail. Have a great day.


Ben Forsberg
TSS
Geno's Garage Staff
Phone: 800-755-1715
Technical Assistance: 770-886-2500
Fax: 770-886-8811
Email: Forsberg@ix.netcom.com
Web: www.genosgarage.com

 

I installed mine with an isolator and used windshield washer fluid from the isolator to the gauge. I also used liquid teflon tape. All was good until the washer fluid started breaking down the tape. I had to take it apart and redo everything.. Mine pressure just kept dropping to 0 pressure.

 

so have you been able to get it working right? i have been fighting this dumb thing for over a year. take the isolater out and it will work for a few weeks put the isolater back in and it work again for a couple more weeks---just back and forth.
usually will work ok around home when i am not towing but when i get on the road and start towing hard it goes haywire

 

What happens if you just take the isloator out completely?

 

My underhood gauge is mechanical without an isolator and it works fine.

 

it will work for a while then to get it working again i reinstall isolater until it screws up again then i remove and it work again for a while ?

 

so, what did you put in its place once you re-taped it? The instructions I had with my FP gauge stated you don't need an liquid in the isolator if the line going from the motor to the isolator is less than 6 feet long, but my fuel pressure gauge has stopped working now, after about a week of working fine. My instructions said to use antifreeze, but I want to put it in there, and not have any air in the system. Will the system purge itself of air once its all together? Or does the liquid need to be vaccum pumped into the isolator?

Scott

 

i used a hypodermic needle to fill my line from the gauge back to the isolater--still has not taken care of the erratic chatter noise problem