Issopro fuel P gauge vibrating ?

[LLewandowski]

My fuel pressure gauge is buzzing , kinda loud . The needle is vibrating back and forth super quick . I've had it hooked up for about 2 months , and it just started yesterday . It is a direct line from the IP to the gauge .



It's read 7psi idle and even worse when accelerating . I know I need to fix the lift pump issue yet (I tried the dealer , wow what fun) .



Any idea whats the deal with the vibes?

 

[MBreyer]

Ok, we've gone thru the same thing. I've now got a dead Pyro (Isspro) and my FP is buzzing again. THey will want $30 for a "snubber" kit. this fixed mine for a few months.



I have no idea what to do, but I'm in the same boat.



Very sorry.

~Matt

 

[Fishin Guide]

I used a needle valve barely cracked open and that has saved my replacement gauge. There are also inline snubbers that can be bought online.



An isolator seems to help as well.



Dave

 

[Diesel Manor]

That's because you have it connected direct. No mechanical gauge can handle a direct connection. ISSPRO has a pressure snubber and we do stock them. You can use it for a direct connection. It should illeviate some of the pressure spikes going to the gauge. We also have an isolator which is a better route for protecting the gauge.

 

[LLewandowski]

Ok thx for the replies .



So a few questions here . Is my guage currently damaged now? If nothing is damaged , why is it buzzing now... . and not before? I'm assuming a snubber is going to be somthing to actually 'reduce' flow through the line , kinda like if I solder closed a fitting and pop a pin hole in it ?



I can't believe a mechanical guage can't handle a direct connection , espically at 7PSI . I'm thinking junk .

 

[DonS]

I can't believe a mechanical guage can't handle a direct connection , espically at 7PSI . I'm thinking junk .

IIRC...



It's not the 7 psi that will hurt the gauge. It's the much higher pressures associated with the flow stopping and starting as the IP is functioning. It's much like a "water hammer" phenomenon in your house's plumbing. Just as the water hammer will eventually destroy fittings, a direct connection to the IP will eventually kill the gauge.



A "snubber" limits the high-pressure transients so they don't get to the gauge. Analogous to (though I don't know if they work in the same way as) an air chamber in plumbing. You might even be able to let a little air into the line (between IP and gauge) to see if that helps - the air would absorb some of the high-pressure transients.

 

[Joe G.]

The pin hole in the soldered shut fitting is the same thing as a snubber. I use a needle valve that is just barely open enough to let the gauge work. My 12 valve has worse pressure spikes than your 24 valve. The needle valve has worked on mine for a long time. However, I use a Westach gauge. It may tolerate pressure spikes better.

 

[Oil Burner]

Your gauge may or may not be o. k. Mine has "buzzed" before but has been silent for the past 40K miles with the needle valve in place.



Jason

 

[Matthug]

I am using a needle valve, but I'm gonna look for a snubber as even with the needle valve cracked open just to the point of the gauge barely working the needle still fluctuates rapidly with RPM's and the gauge buzzes. It's very annoying. But 12 valves will have much harsher pressure spikes than a 24 valve will.

 

[WDixon27]

i am running a isspro 60# fp gauge with a isolator, i just upgraded from a 30# when it became too small after i changed my nearly dead lift pump, (i max out at about 32# which should be fine but i didn't want to be running the gauge at max most of the time) i bought the snubber with the new gauge and it was too effective, it took about 10 minutes of highway driving to get to 30# and a like time to return to 0, i said the hell with it and hooked up directly and it doesn't fluctuate more then a couple pounds at idle, so maybe the isolator dampens it a bit

 

[Matthug]

You might kill your isolator that way... . your snubber was too small.

 

[LLewandowski]

Thx everyone . I guess my next move is to try some kind of snubber .



When I pull the fuel line off the IP , I'm bound to get air in the gauge line , do you think I'll have to bleed that again from the gauge? It will be a pain in the butt to pull the a pillar , which is already riveted ect... basically like starting over .

 

[Matthug]

I just bought one like this from this guy-

http://cgi.ebay.com/ebaymotors/New-...ryZ33674QQssPageNameZWDVWQQrdZ1QQcmdZViewItem



10 micron sounds about perfect, and it's brass too.

 

[MBreyer]

Question here,



So since mine has a snubber, and it's back to buzzing, what should I do next to it? Is it another $30 snubber? Or perhaps a different gauge?



Thanks guys... .



~Matt

 

[Joe G.]

At one time I had a mechanical fuel pressure gauge. I didn't like the thing because it was kind of ugly and it vibrated no matter what combination of needle valve and snubber I used. I have replaced it with a 40 PSI Westach gauge. This one is electronic. I use a grease gun hose to isolate the sensor from engine vibration. No funny business with anti freeze or anything like that. I kept the needle valve and snubber. I also checked the gauge for accuracy with a couple of mechanical gauges so I know that it is telling me the truth. No needle vibration or buzzing. It has been working fine for over 150K miles. I recently had an overflow valve problem. Fuel pressure dropped to 6 PSI before I got home. I have an alarm rigged on fuel and oil pressure. It came on when pressure dropped below 10 PSI. The gauge showed the same pressure.

 

[WDixon27]

i bought the one near the bottom of the page when i got my 60# gauge, i pulled it out the threw it in my tool box, now it dampens the vibrations of my crap drawer

You might kill your isolator that way... . your snubber was too small.

 

[LLewandowski]

i bought the one near the bottom of the page when i got my 60# gauge, i pulled it out the threw it in my tool box, now it dampens the vibrations of my crap drawer

hahahahahahaha , thats funny . I'm a big fan of doing this right the first time , I knew about isolators , but people told me they go bad , so thats why I din't install one . I figured I was capable of running a hose that won't leak into my cab .



Never knew about the snubber , but it seems like it din't work for alot of people anyway . The digital looked cool , but at the same time I was trying to cut cost .



I work in HVAC and I use 'mechanical' gauges that handle 300psi+ , just seems funny that this guage can't , but I guess its a vibration thing?



I'll tell you what though , it never said anything about having to include anything with the instalition of this guage to make it work properly or to not damage it , so if its damaged I better be able to return it , and I'm guessing it is since it din't vibrate the first 2 months and now it does .



Anyway , thx to everyone for the replies , love this forum .

 

[DonS]

I work in HVAC and I use 'mechanical' gauges that handle 300psi+ , just seems funny that this guage can't

Maybe it can. Apparently, though, it can't handle the pressures that are present when it's hit with the shock wave caused by the flow stopping every time the IP stops sending fuel to an injector. Depending on flow rate, pressure, how fast the "valve" closes, etc. , you could be hitting the gauge with several hundred psi, several hundred times per second.

 

[Pliska]

I missed this thread in my normal searches for "ISSPRO" (see the spelling in the thread title).



My guess is that LLewandowski's gauge didn't vibrate initially due to the extra friction in a brand-new gauge, before the mating gears wear into each other. In other words, all mechanical gauges loosen up a small amount with their initial use. What type of snubber are you using?



Thanks,

Michael Pliska

 

[WDixon27]

cool bump on this thread i couldn't remember when i bought my 60# gauge, started reading lower and lower then nothing a couple months ago, reminds me i need to buy another 60# gauge