Installed fp gauge on friday. Seemed to work fine a steady reading of 12-13 and 8-9 WOT. Sunday started and drove truck the reading was 5. I checked the line and saw lots of air in it. what can i do to help prevent getting air in the line. The fuel line install was from top of filter directly to fuel line with no isolator to gauge. what are some things i can try and also when first installing the gauge what is a good way to fill the fuel line with minimal air in line.

Thanks,
Hoss15

 

I'm setup the same way but mine comes out on the bottom of the filter... Banjo fitting. But the air in the line shouldn't change the readings that bad.

I think you got a LP going south on you.

You might want to bump the starter and see if it making any strange noises (grinding or un-even buzzing).

I would now also consider doing a volume check of the LP.

My LP was doing something similar. When the buzz of the pump was nice and even the pressure would go up to 13-15 PSI then when it got un-even and started grinding then the pressure would fall 5-8 PSI.

Or...

You got a air leak in the fuel line from the tank to the LP... But you never mention anything about poor starting or run issues...

Just my 2 cents worth...

 

Yeah, it starts fine and runs fine, i think my install of the line could be a little better. and i will check and listen for the "strange noises" when the starter is bumped. The volume check. How is that done? can i do it myself? and how much diesel should i see when the volume check is done? I'm still learning about these CTD's.

Thanks,
Hoss15

 

Look up by the VP44 you will see a fuel line with a piece of rubber hoses joining it. All you got to do is slide the rubber hose over to the VP44 and disconnect the filter line. Now add a extended piece ofr fuel line so you can put it in a gallon jug. Then bump the starter. After the LP runs for 25 secs measure how much fuel is in the jug. There should be more than 45 Ozs. of fuel. If it's close or below this then change you LP.

I took a gallon jug and measured 45 ozs of water into it and marked it.

Run this test a few times not just once. You will see trend if the pump is haveing problems.

As I found out my LP pass the first 2 tests but failed the next 7 tests.

 

Air makes no difference in the reading.
I was very surprised on Sat when I changed a FP gauge on a '97 I installed over five years ago to I new one.
Owner wanted a different look even though the old gauge worked fine.
Absolutely no fuel was in the old gauge or line.
All along my worry was getting some diesel in the cab during the change over, my worries were unfounded.

 

Thanks... I had no clue that air made no difference in the reading...

Your lucky... I had forgot to tighten a brass fitting on mine and had a small weep of fuel in the cab... Trust me... You will smell diesel very clearly if there is a weep or leak in the cab! As I learn just turn the needle valve off and get home and repair the leak.

I LOVE NEEDLE VALES!

 

Thanks for the info. I will give these tests a shot. The LP was replaced not too long ago from the dealer, should be under warranty.

Hoss15

 

Went to lunch. Thought i should pull gauge out and have a look. Found the line to the back of the gauge was kinked. oops.... Problem fixed... gauge actually works better now with 15 idle and 10 when pushing the go pedal from a stop sign. I should have checked the small things first.

Thanks for all the help.
Hoss15