Rail-mounted fuel gauge install issue

[Coelacanth]

I'm almost embarrassed to post this question for what ought to be such a simple install! I received a rail-mounted fuel pressure gauge from Full Throttle Speed, which included the straight adapter and 90-degree brass elbow. Removed the Schrader valve from the rail and put Teflon tape on all the male threads. This should be idiot-simple, I say to myself.

Installed the straight adapter first, it threaded on all the way and stopped, so I snugged it up. That's when the problem happened. No matter how I tried to thead on the 90-degree elbow, it never finished threading on with the gauge facing where I wanted it!

When it seems a bit too loose for my liking, it's facing where it should, but if I try tightening the 90-degree elbow, it gets really tight with the gauge position at least a full half-turn AWAY from where it needs to be. WTF?? How do you get the thing to thread on so it's facing up and the gauge face is visible? I don't want to over-torque the 90-degree elbow into the straight adapter for fear of stripping out threads...grrr...

 

[Nick Micale]

Just me, and my opinion, I will never install a fuel gauge on the rail?

Owners can do what they want, but I want no responsibility if it leaks.

This is the results of a fuel leak at the regulator when driving:

 

[Nick Micale]

After a few thousand dollars and MANY hours of labor, it look like this now!

 

[Coelacanth]

I agree with you, Nick...this is actually only temporary. After I confirm fuel pressure readings before and after I install a Walbro fuel pump & hotwire kit, I want to remove the gauge and will replace it with a transducer that I'll wire into a Reveltronics UTCOMP board to display & log fuel pressure. I just want to make sure it's accurate, and make sure the new pump & hotwire kit are working properly.

 

[Coelacanth]

Back to my question...many of you have rail-mounted fuel pressure gauges. Am I the only person to have the elbow thread on so when it's snug, it's pretty much 180 degrees away from where it needs to be?

 

[Heskahoka]

You are not alone, I had the exact same issue you had a few years ago. Too tight, too loose, I could never get it right. I ended up walking away and drinking a beer.
Next day, new try, I played with it and got it right. If I recall, I went past my point of comfort on the elbow and then backed off a bit on the coupler. Good luck, it is a dance.

 

[Coelacanth]

Well, I got it installed with no leaking. I removed it all, disconnected the gauge...and after marking the top of the adapter with a chalk pencil, I cranked on the elbow a full extra half turn. It was way tighter than I would've gone, for certain, but my thinking was "it's either gonna break or it's gonna be on damn good". If it broke, I would've looked into a refund, but fortunately it reassembled fine and definitely won't leak or even budge.

 

[GNRick]

I think most people use the paste, not tape. Maybe that is what caused the problem? My Autometer electric gauge instructions recommended a small dab of paste.

 

[Powertechn2]

I always use liquid/paste. Teflon tape is really designed to lubricate the threads so you can tighten it, whereas the paste/liquid does that, and also aids in sealing. Plus you just give it a wipe around after and it looks nice and clean.

I have a rail mounted gauge set-up I have wanted to install, but want a T so I can check with my actual pressure gauge to make sure it is accurate.

 

[Joeld]

What is the paste called?
Thanks
Joel

 

[TurboBuRick]

The fuel rail port is a flair seat fitting that requires NO sealer.

The right 90* fitting for the job has a female swivel so it can be clocked in any direction.

 

[No disintegrations]

The fuel rail port is a flair seat fitting that requires NO sealer.

The right 90* fitting for the job has a female swivel so it can be clocked in any direction.

Yes to this. Paste, tape, dog doo will do nothing to seal these. They seal on the metal to metal flare and the nut floats free until tightened, so fluid would leak past the nut even if the threads were sealed.

Never use tape on an engine or where pieces of tape can clog things like fuel or oil passages.

 

[1952ray]

 

[Coelacanth]

The elbow this fuel gauge came with has no swivel, it's just a cheap brass 90-degree elbow. Sure would've been easier if it had a swiveling end. I'll remove the Teflon tape and see if everything seals without. I have anaerobic thread sealant handy if it's needed. Joel, it's available as Permatex High Temperature or High Performance Thread Sealant; I believe they're the same product, just comes in 2 different sizes of tube.

 

[Pronto]

http://www.ebay.com/itm/PRE-60451BL...e-Thread-Straight-Fitting-Black-/330768797019
A union or elbow with sealer and your done.

 

[TurboTGuy]

After a few thousand dollars and MANY hours of labor, it look like this now!

View attachment 287439

I know that car............

 

[Coelacanth]

Both of the swivel fittings linked above end in a 1/8" NPT male thread, and therefore would require a female-to-female 90* elbow in order for my fuel gauge to work, because the gauge is 1/8" NPT male, too. How about something like this? This has the swivel, would go right on the rail, and I could attach the gauge right on with no elbow. I'll cap off the male end for now, but is needed later for attaching a transducer that I will wire into a UTCOMP-PRO to display & log fuel pressure; this would do the trick, right?

http://www.jegs.com/i/JEGS-Performance-Products/555/100532/10002/-1

 

[bison]

Both of the swivel fittings linked above end in a 1/8" NPT male thread, and therefore would require a female-to-female 90* elbow in order for my fuel gauge to work, because the gauge is 1/8" NPT male, too. How about something like this? This has the swivel, would go right on the rail, and I could attach the gauge right on with no elbow. I'll cap off the male end for now, but is needed later for attaching a transducer that I will wire into a UTCOMP-PRO to display & log fuel pressure; this would do the trick, right?

http://www.jegs.com/i/JEGS-Performance-Products/555/100532/10002/-1

I use these all the time to thread pressure transducers into. Quality USA made stainless pressure transducers with high burst pressures. I don't rec the cheapie type mounted gauges typically seen on cars. They are prone to failure and a fire is an expensive avoidable lesson. Fragola has a -4 female to 90* 1/8npt but a female 1/8 coupler is needed to get the same effect. I prefer to use the fitting in the pic and cap the end if not used. Keep in mind anything threaded into/onto the engine has to be able to survive at the frequency of the engines harmonics indefinitely. If in question about a gauge or transducer you need to contact the manufacturer for their list of specs. If they can't come up with this info don't bolt it on!


Sent from my iPhone using Tapatalk

 

[Coelacanth]

I use these all the time to thread pressure transducers into. Quality USA made stainless pressure transducers with high burst pressures.

Bison, are you referring to the Jegs fitting I linked? Or the ones before? Sorry for the confusion. If there's a particular brand's fitting you suggest, let me know which and where I can get it.

 

[Coelacanth]

I researched -4AN straight adapters with 1/8" NPT male ports, Fragola, Earl's, JEGS, and a bunch more...they're all made of the same anodized 6061 T6 aluminum, so I guess it doesn't really matter which one I buy. Funny how some are available for under $8 while others are asking $35+. Ridiculous.