Engine/Transmission (1994 - 1998) fuel pressure gauge ?

[JAmos]

I'm getting ready to buy a fuel pressure gauge and am wondering how well they work. I have autometer ultra lites and am looking at a 0-100 psi mechanical gauge with an isolater. I'm thinking that the lift pump might make the needle flutter but should give a fairly accurate reading. Thanks for any tips.



Jordan

 

[EKlem]

You don't need to get a gauge that goes all of the way to 100psi. My gauge goes to 30 and I rarely peg it. There won't be anything wrong with a 100psi gauge, it just won't be as easy to read out of the corner of your eye.



You are correct that the lift pump will make the needle flutter if you only have an isolator and gauge. You can buy a snubber valve for 20 bucks or so or you can build your own needle valve. The advantage of the snubber is that it is easy to order when you get your gauge and you don't have to worry about it. The advantage of the needle valve is that you can adjust it to get quicker response to changes in pressure and you can completely shut it off if something ever goes wrong with the gauge. If you do a search for needle valves, there is some pretty good information out there.

 

[Joe G.]

100 PSI is way overkill. I use a 40. It gives me a more accurate reading than a 100. If your fuel system is in good shape it can peg a 40 PSI gauge in some conditions. Mine does. I think the needle valve is the best way to go. This is how my needle valve is set up:



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[JAmos]

In the autometer ultra lites they only have 0-15, and 0-100 psi gauges in a mechanical gauge. Now if I went with an electronic gauge they offer 0-15, 0-30, and 0-100 psi gauges. Should i consider an electronic gauge or should I stick with mechanical? I can get the 100 psi mech gauge and isolator for a little over $100 while an elec gauge with sender run ~$200.



Pretty sure one of the performance shops told me that i should have 20-25 psi at idle and40-50 at wot, hence why I haven't considered else but the 100psi unit.



Jordan

 

[Joe G.]

I use a 40 PSI Westach electronic gauge. It has been very reliable for a long time. You can get almost any size gauge from them. Just ask for what you want. When I was looking for a fuel pressure gauge the choices as far as I could see were 30 and 60 PSI. I asked Westach if they had one for 40. They did.

 

[JAmos]

I'm gonna stick with autometer so they all match. I'm prob also gonna get the 100 psi unit even though it is a little overkill I will always know what pressure I have. Plus its about half the cost of the electric gauge.



How bad does the gauge needle flutter without a snubber or a needle valve? I guess if it bothers me then I can always add one.



What are the pro's and con's of a snubber and needle valve?



Jordan

 

[WDixon27]

the flutter is to be avoided not so much because it's annoying as it's destructive to the gauge, i tried a isspro snubber and it all but killed the action of the gauge it took 5-10 miles of interstate to get up to pressure (other people have reported good luck with them though) i went to a needle valve and like it better. it depends on the condition of your lift pump on how bad it will flutter, my orignal pump was about half dead and didn't flutter and my new pump didn't flutter for about 3k miles but started fluttering bad once the pump broke in

 

[EKlem]

WDixon is correct that you need some sort of needle valve or snubber. Without it, your gauge will wear out quickly. A lot of gauges will also make a really annoying ticking noise in time with the pulses from the pump. I installed my gauge without one and when I opened the hood with the engine running, all of the hoses and isolator for the gauge were jumping around from the pressure spikes. I think that if you install it without one, you will be pulling it apart quickly to put one in.