2nd Gen Non-Engine/Transmission Westach FP Gauge Installed (FINALLY!)

[SBettencourt]

After a LOT of consideration I finally purchased and installed a Westach 0-16psi fuel pressure gauge in my virtually stock '01 3500. I used to occasionally check FP with a service gauge but I am concerned about an "in operation" incident that could result in low pressure.



Anyway, the gauge works great but...

I installed a Vulcan BIG LINE and pump relocaton kit last summer.

The pump was replaced when I got the truck June, 05.

Service gauge pressures with the original lines was around 12 psi on a 100 psi gauge so I was expecting similar with the current setup. Unfortunately I don't recall checking pressure after the Vulcan kit install. So much to do - so little time.

Pressures with the new Westach gauge runs 15+. It will drop a couple WOT getting up to speed on the highway.



I should have purchased the 0-30 psi gauge and the Vulcan kit was worth every penny to help supply a good amount of fuel to the VP44.



I am going to see if the gauge readout increases with higher resistance from the sender (or opposite) as I might add a small resistor in the circuit to move the needle down a bit. Funny thng is I read yet another FP gauge thread just after ordering that recommended a 30 psi gauge over the 16 even for stock apps.

 

[JCyrbok]

may just be air in the sender line. My FP used to be a little screwy after changing fuel filters or if I was doing something that would let air in the line. It would usually return to normal after a couple of days as the air moved out of the sender. Just a thought. Of course it may just be the new lines moving more FP.



Hope this helps

J-

 

[Thomas]

... I am going to see if the gauge readout increases with higher resistance from the sender (or opposite) ...

This page from the Westberg Manufacturing Incorporated catalog should answer that question for you.


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The Westberg site has changed a bit since my last visit. It's now possible to Build an Instrument from this page: http://www.westach.com/.

While Westberg has long offered custom gauge configurations (it took a telephone call), it's now possible to configure and price custom gauges 24/7.

 

[SBettencourt]

Hi J,

I bled the line to the new gauge sender but there could very well have been air in the service gauge line.

I am really glad that this thing has such good FP after all the horror stories of short lived LPs.

 

[Thomas]

may just be air in the sender line...

Both of my Westach pressure senders seem to work quite well with the air that I intentionally trapped in the lines. The page that I linked above actually refers to air pressure as a use for the 387 series senders. Come to think of it, my tire pressure gauge also manages to work with air in the line.

 

[WestTN]

A little air in the sensor line will NOT change the accuracy of the pressure displayed. It will provide a slight amount of damping. Air in the line is only a factor with isolators and then only on the gauge side. They can read low even when the diapragham is bottomed out. A resistor in the line will introduce inaccuracy in the electric gauge. It is a balanced bridge circuit. And last, but not least, A 100psi gauge is a poor instrument to read in the 12 to 15psi range. A laboratory grade gauge would be fine, but consumer gauges are generally no better than 3% accuracy and that would only apply to the center 1/3 of the range, 33 to 67 psi. Accuracy really suffers outside that range.

 

[SBettencourt]

Dennis, What is your fuel pressure.

I also fully agree with all on the 100psi gauge inaccuracy and air in the lines. I never bled an oil pressure gauge. I also never used an isolator so I have no experience there.

 

[Joe G.]

Steve,



I don't think you have a problem. What you are looking for is low pressure. I don't think the sending unit is going to harm the gauge if there is high pressure. Mine is pegged quite a bit (12 valve) since I put in a new overflow valve. I need the gauge to warn me of low pressures. High are not a problem.

 

[RustyJC]

I have a Westach dual combo fuel pressure gauge that displays pre-filter and post-filter pressure. The pre-filter pressure is 16+ PSIG at idle with the post-filter around 14. 5 to 15 PSIG - this still on the original lift pump! All I've done on mine is install larger banjo bolts, so the pressures sound very similar to what you're seeing.



Rusty

 

[SBettencourt]

Thanks to everyone that responded. This is a great forum!

 

[WestTN]

SBettencourt, my pressure at idle is ~14psi at the outlet of the filter and ~15 at the inlet.