Electric fuel pump presssure

[mike42]

I have a Carter pump with Holley fuel pressure reg. and fluid gauge. When I first start it up the gauge shows just under 2#. After driving awhile there is no register at all in the fluid gauge. Just wondering if anyone knows why ? The car runs great though.

Thx....Mike

[ford3]

your gauge is bad, if no pressure the engine would not run as you stated

[19Fordy]

You have to adjust the fuel pressure regulator while the engine is idling. It's easy to do and worked for me..

[mike42]

Fordy.....I'll give it a try and re-adjust.

Thx

[Joe AZ]

I've got the same issue......Holley regulator with liquid pressure gauge. If I adjust it to 2 pounds pressure, at either fuel pump only pressure (not running) or start-up pressure, after driving for 10 minutes gauge will show zero. I've read that the liquid filled gauge may be the issue. (HAMB thread)
Joe

[mike42]

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I re-adjusted as mention here and it was just under 2#.........took for a short drive and came back and checked it and it was flat lined, but the car runs great ! Guess I shouldn't worry about it !

[V8 Bob]

Originally Posted by mike42

I have a Carter pump with Holley fuel pressure reg. and fluid gauge. When I first start it up the gauge shows just under 2#. After driving awhile there is no register at all in the fluid gauge. Just wondering if anyone knows why ? The car runs great though.
Thx....Mike

Simply drain the fluid out of the gauge and it will work fine.

[koates]

Hi there, I have the same issues also with my stock standard 1934 ford. I have no electric fuel pump or regulator. I fitted a quality stainless liquid filled gauge between the mechanical fuel pump and carb (no rubber fittings, all metal) and when engine and gauge are cold it reads 2.5 psi. When all warms up gauge reads zero but car runs fine as usual. I read somewhere that as the gauge and liquid heats up there is an opposite push on the Bowden gauge internals which cause it to read zero. I thought these gauges were designed to work In hot under hood conditions. I will buy a non liquid filled gauge and try it out or how do I get the liquid out of the gauge. Drill carefully a tiny hole in the bottom of the gauge case ? Regards, Kevin.

[gmc1941]

This style of gauge was designed with fluid for the damping of the needle deflection. Usually the gauge is designed for more of an ambient temperature of a building I would say 70-110. The temperature could also forcing the fluid out.

[V8 Bob]

Originally Posted by koates

Hi there, I have the same issues also with my stock standard 1934 ford. I have no electric fuel pump or regulator. I fitted a quality stainless liquid filled gauge between the mechanical fuel pump and carb (no rubber fittings, all metal) and when engine and gauge are cold it reads 2.5 psi. When all warms up gauge reads zero but car runs fine as usual. I read somewhere that as the gauge and liquid heats up there is an opposite push on the Bowden gauge internals which cause it to read zero. I thought these gauges were designed to work In hot under hood conditions. I will buy a non liquid filled gauge and try it out or how do I get the liquid out of the gauge. Drill carefully a tiny hole in the bottom of the gauge case ? Regards, Kevin.

There should be a small plug on the gauge, used to fill the liquid. Just remove it, and allow the fluid to drain.
This topic has come up often. They ought to stop selling the liquid-filled fuel pressure gauges, as there's no good reason to have one, besides the fact none of them work properly.

[Joe AZ]

Originally Posted by V8 Bob

There should be a small plug on the gauge, used to fill the liquid. Just remove it, and allow the fluid to drain.
This topic has come up often. They ought to stop selling the liquid-filled fuel pressure gauges, as there's no good reason to have one, besides the fact none of them work properly.

I drained my gauge today....took it for a ride up to temperature, checked it a couple of times. It's still early, but it seems like it's holding the the 2 1/2 pounds of pressure I set it at initially. Thanks......
Joe

[Talkwrench]

I use this Marshal fuel pressure gauge on all my cars very cheap at $15 but very good from Phil at Rpmltd, great guy, he supplied a 450 holley reconditioned , built to my spec with quick change etc for $250!
Shameless plug.. ; oP http://www.ebay.com/itm/HOLLEY-DEMON...item43a0117c85

[mike42]

Thanks guys I'll drain it today and give it a try.

Mike

[koates]

Thanks to all especially V8 Bob for the detailed info. Regards, Kevin.

[19Fordy]

Mike 42, I let the liquid drip out of my fuel pressure gauge that is attached to my Holley fuel pressure regulator and now the gauge reads accurately.

[mike42]

19Fordy.....

I just started up my '40 yesterday for the first time this year. I still have the fluid in my gauge. Just unplug that small seal and let it drain ? I've have it set around 1.5 psi as it sits now. After draining what should I set it to ?

Draining has no effect on the gauge operation ?

Thx....Mike

[19Fordy]

Hi Mike, I just did this yesterday.
1. Shut off engine and remove fuel pressure gauge.
2. Remove the plug on back of gauge and let the silicone fluid drip out. My guage also had 3 little screws on the back. I unscrewed them thinking it would hasten the "dripping" process, but I don't think that was needed.
I think you will be ok just removing the plug.
3. Re-install plug and/or screws.
4. Smear some of the dripped out silicone fluid on the gauge threads as a lube and reinstall gauge.
5. Start the car engine and adjust the pressure to what you want. I set the pressure at 5 psi but I am running a Holley 390 4 bbl. which can handle up to 7 psi. On the stock carb I would run about 3 psi.
6. The needle will jump right up to your setting and "flutter" just a little bit.

[mike42]

Fordy thanks......I'll try to handle today, but we're suppose to get some snow today so we'll see. My barn is not heated !!

I have it set at 1.5 psi right now and will up it to 2.0 psi after draining.

I'll advise when done.

Thx...Mike

[mike42]

Fordy.....

Drained the gauge and started it up and adjusted to 2.0. Perfect...no wobble of the needle at all. So why have the fluid in there to begin with ?

Thx...Mike

[19Fordy]

Originally Posted by mike42

Fordy.....

Drained the gauge and started it up and adjusted to 2.0. Perfect...no wobble of the needle at all. So why have the fluid in there to begin with ?

Thx...Mike

Glad it worked. Main reason for fluid filled gauges is lessens vibration. But there is more. Here's the rest of the story.
http://www.wika.us/Liquid_Filled_Gauges_en_us.WIKA