2nd Gen Non-Engine/Transmission Under hood fuel pressure gage

[GeorgeW]

After reading all the posts re lift pump failures I am now a believer that the fuel pressure needs to monitored.



I picked up a 0-30 psi gage (glycren filled) from NAPA and mounted it to the outlet port on top of the fuel filter housing. It is reading 12 psi at idle. This seems to be in the range that I read in the posts for those who do have not installed pusher pumps.



I have a completely stock engine (1999, 92,000 miles) and use the truck for hauling my slid-in camper around.



I can think of no reason to constantly monitor the fuel pressure (please tell me if I am wrong here) so I am thinking about mounting the gage somewhere under the hood or even leaving it mounted on top of the fuel filter housing.



I can then check the idle pressure from time-to-time.



I will appreciate any comments as to problems with my thinking.

 

[rblomquist]

Keeping it under the hood will basically do you no good. All that will tell you is if the LP is totally dead. You need to monitor the pressure while the truck is under varying loads. Now, the best option is to have one in the cab you can see at all times however, you can certainly buy/make a test gauge that you can take and tape to the windshield every once and a while to verify pressures.

 

[Bob Wagner]

but if you want to keep is simple and just monitor once and a while you can add a mechanical gauge on top of the fuel filter housing using the 1/8" npt port



that would be better than having no gauge at all

 

[raf2000]

Keep an eye on it. 12 is a bit low. 15-16 new. WOT pressure is very important. Like Bob said, really need to monitor it continuously in the cab under various conditions. I got flucky after reading similar threads, installed a gauge and saw 6 at idle and 0 at WOT!! (Wide Open Throttle) Changed it out and get 15 idle and about 8 WOT. THE WOT value of course will vary depending on how much bombing you have done to the fuel system (injectors, box, etc)



I had 104K miles when I changed mine, FYI.

 

[ox1]

IMO some folks just get too carried away with the importance of some items. I have had a pump completely die already - to the point that it took hours(!) to get it bled after running out of fuel. Drove it another YEAR like that! (Not knowing the problem. )



It is said that the inj pump does NOT need any head pressure as such and will work fine with overhead fuel tank - gravity feed alone. Once it has fuel the pump will suck it from then untill any air gets in the line. From my experience I would say that is 100% true.



That said - I also now have a guage that I check occasionally.



http://www.snowest.com/fusetalk/attachments//PresGuage1.jpg



http://www.snowest.com/fusetalk/attachments//PresGuage2.jpg



When the pump is new it will just peg this guage. As time goes you can see it slowly get lower. With the place that it is mounted I can see the guage through the open hood and rev the motor (unloaded) and see how much drop.



I have replaced the pump when it has gotten as low as 2# at rev I think. (It was a while since I had last checked the pres on the day I noticed it that low. ) I see no performin' ants differance with old pump or new - with stock motor anyhow. As long as the inj pump gets fuel it seems to be a happy camper.



Personally - I like to change my pumps in the fall - before sledding season and cold "side of the highways". Seems like one/year or 25K miles and it is getting low.

 

[GeorgeW]

Thanks for your response, guys. I think I will leave the gage mounted to the fuel filter houing for the next few weeks. We are heading out to Colorado in a couple of days (about 1500 miles from here) and I will be able to check the fuel pressure when I stop for fuel.



GeorgeW

 

[Ron Bissett]

Originally posted by GeorgeW

Thanks for your response, guys. I think I will leave the gage mounted to the fuel filter houing for the next few weeks. We are heading out to Colorado in a couple of days (about 1500 miles from here) and I will be able to check the fuel pressure when I stop for fuel.



GeorgeW

Seems like you wan't the members to side with your thinking not asking about weather its wrong to mount a gauge on top of the filter ,every one knows that its not a good place to mount it vibration will cause it to die sooner or later filled or not ,You think looking at the gauge when you stop will do it. think again , the injector pump contrary to what other said will suck just enough fuel to keep the motor running and destroy itself do to heat ,the injector pump is cooled by the 75 %fuel returned to the tank , Some times some folks get a way with not doing it the correct way and want others to do the same , get some tube and extend in to the cab or get a electric set up and then you can see how things are in real time . :-{} Ron Bissett in Metro Louisville KY

 

[SEmerson]

A dirty fuel filter will give a high idle reading and a very low load reading. You have to see it under load.