Ok, so after my last fuel filter change I noticed I had difficulty getting it started. I decided to check the fuel pressure just to make sure the lift pump hadn't crapped out on me. I connected a manual gauge to the test fitting on the IP, tested both engine off and while running. Zero reading for both!!! Checked the gauge on a gas motor and it worked fine. Am I doing something wrong, or do I need a special gauge for a diesel??? Or is it time to get a FASS or the like and be done with it.

By the way, the truck starts with just a touch of the key, and runs just fine under any condition. It runs and sounds fine so I'm thinking I may be doing something wrong???????

Thanks for any help!!!

 

Hard starting after a fuel filter change is not unheard of, but 0 PSI at idle is not good!!!

If you are certain that your gauge is good I would suggest replacing the lift pump or get yourself a FASS or GDP/Walbro.

I'm sorry to be the bearer of bad news, but your VP44 may soon say goodbye. They don't last too long with 0 PSI at idle.

 

Don't drive it until you get yourself a new LP

 

Well I just drove(the wife's car) up to advance auto to see about getting a new fuel pressure gauge just to make sure the other one I used wasn't bad...

On every one they offered, it said "not for use on diesel or flex fuel vehicles". Is there a special or certain type of gauge that should be used???
I asked the guy behind the counter and he said that it was because diesels don't have any fuel pressure. I knew then it was time to come back home and ask for some help on TDG.

Also, I haven't tried the test fitting on the back side of the fuel/water separater...not sure if it matters since I'm didn't get any reading at the IP???

 

bump your starter and leave your key on, jump out of your truck and listen .... you should be able to hear the lp running if not replace it

 

My lift pump does run when I bump the starter. I can hear it as well as feel it vibrating. Is it possible for this to happen and still not provide fuel to the IP???

 

My fuel presure gauge will not work if I srcew it in all the way down on the shrader valve. Install it all the way, then back it off up to a couple of turns, a half turn at a time to check it.
I have heard of gauges not being diesel compatable. If I recall correctly, they will work fine until they..............quit working.
An upgrade to a new pump of some sort will get rid of a lot of frustrations in the future. I have an Airdog, but there are cheaper alternatives. Do not buy another
DC pump though. Anything but that!

 

A lift pump may make noise but produce no pressure. Mine was just like that. Purred very nicely, but produced 1 psi at idle. Don't rely upon the pump noise. Trust the fuel pressure gauge. Replacing the LP is very simple if you get a stock replacement.
-P

 

I agree had the same thing happen 0 fuel pressure. I thought it was the gauge so I tried it on a buddy's truck LP was junk. Replace it...............

 

Your gauge may be OK, but maybe your not connected in the correct fitting, Speaking of Lift Pump, good idea to replace the OEM LP with aftermarket,, I found good deal on ebay, I got a Airdog, it does Air as well as water and fuel. best price i could find. Good luck

 

Thats not exactly true. A pressure guage is a pressure guage. There is no component in diesel fuel that will eat away a pressure guage or make it stop working. I think the main reason they say "not compatible with diesel" is because the guages are adversely affected by the pulsations from the fuel system. If you do not plumb the guage correctly (use needle vallve or pressure snubber), the guage will eventually fail.

Therefore, its easier for the manufacturer to just say "not compatible with diesel".

 

Like Dr. Evil said, "a pressure gauge is a pressure gauge"

When you order a fuel pressure gauge from ISSPRO or Autometer or anyone, no one will ask you if it's for a diesel.


I ran my truck for about 5 minutes with no fuel pressure ( I had to get it off the highway) and the VP died the next day. Might be coincidental but I also have run a fuel pressure gauge since almost day one.

Jeff

 

Hey Homestead - got your truck up and running?

 

Hey Evil

I'm still driving the truck, not very hard though. It's only making about 15 lbs of boost right now and as you can imagine, the EGT's can get way out of hand in a hurry.

If all goes right, I should be heading down to Piers around the end of April to have a Cummins Reman head dropped on it. I could think of better ways to spend $4000 but oh well, could have been worse!!

Jeff

 

Actually, the diesel will slowly eat away at cheap rubber. I had a rubber part in the female schrader connection of my auxiliary mechanical fuel pressure gauge. I used it a couple times to verify my electric gauge in cab. About a year later, I went to use it again and the rubber o-ring had basically disintegrated. It was in pieces. I had only used it a couple times, but it had evidently absorbed diesel in the past and that was enough. So keep this in mind.

The other reason I have had mine show zero lbs or low lbs was after changing the filter too. Come to find out that their was air in the filter canister and since that's the top of the system, the air didn't purge out, but it did give me false low readings. I had to crack the fuel canister cap (on my 01) and bump the starter until diesel poured out the top. Then cinch it back down. Then my pressures were good again.

Just sharing what I have seen. YMMV

Steve