Picked up a 98 4x4 24 valve. Ran like a dog (pre turbo Ford) on the way home pulling my 12 valve on a 4K trailer. I wanted freshen everything up (oil, filter fule filter, air filter etc.) I changed fuel filter, drained and refilled bowl, read post on key to start then on for 25 sec to prime. I can not hear the LP running. I do hear a couple of clicks from the relays but that is it. I cracked one of the 'test ports' on top of the filter housing to bleed the air from the filter using the key to start then on procedure.....I never got any fuel. Got over a 1/4 tank of fresh fuel. cracked the #1 injector just for kicks....of course no fuel. My 12 valve was easy to prime. OK, I have read bunches of post that all sound like the LP is dead....could the VP44 have been pulling fuel with out the LP? I can see the LP but without 8ft arms I don't know how I can ever get to it...

 

Yes, the VP44 can pull fuel without the lift pump, but it will not fill an empty filter. You can reach the lift pump easier from underneath.

 

the vp may be junk now too. i cought my lift pump on the way out, right after i got it, i changed fuel filter daj. valves and checked the fuel pressure it was dropin off at WOT, so i had it changed, would of done it my self but i was realy bussie(fair week, 4-H and stuff).

after ya get it fixed GET A FUEL PRESSURE GAUGE!!!!!!!!!!!!

 

Thanks Guys! I got to thinking last night and I parked it on a slight incline... yea just enough the fuel ran back into the tank with the filter canister open. I will try to check the LP out today, but it seems obvious it must be bad or it would be pumping the canister full. And after reading all the post on LP and IP woes, I may well be in for a new VP44. It seems to me the LP really is ment to keep the system primed more than it is to supply fuel, as it appears the VP44 can pull enough fuel to meet it's needs as long as the system is prime and tight. Is this thinking correct?

So now for the next question: As the CTD does use more fuel that BMW applications, and if you start moding it for HP more still; all the post about aftermark fuel pumps are starting to make sence. For a deisel to make more pwr it needs two things...Air and Fuel! So the VP44 seems up to the task (chip for more performance) as long as it gets plenty of fresh fuel, hence orginal LP is not up to the task and should be upgraded so the VP44 gets the fuel it needs plus some excess for cooling via the bypass. Am I on track now?

 

Removed the connector from the LP and put a voltmeter on it to insure I was getting voltage. Switched on the key and read 8V (but it has no load). Bumped the starter and read 12V for 20 or so seconds. Good I think!

Removed the LP (and no I didn't need 8ft arms, just 4ft skinny arms) and no supprise it had fuel in it. Hooked it up to a battery and nothing. Lowered the LP supply line and the tank siphoned. Took Pics and posted. So I'm ordering a LP and taking it from there.

I mentioned in the 1st post the truck didn't run strong on the way home from purchase. I was pulling my 92 12V on a trailer and guessing the combo was about 8K or less. It felt like the turbo was hardly kicking in...I could feel a little power at about 2200 to 2600 rpm but that is waay high compared to my 92 12V. Actually the 92 12V could have run circles around the 98 24V! I have read all the 'dead petal' post on the VP44 but have a hard time beliving my VP44 is bad (yet) because it pulled (not as strong as it should have) all the way to 70+MPH pulling the load I described above. Hoping the LP will return the performance...

 

In the kit my friend bought he also bought a pilot light and sensor in a kit that is a normaly closed switch at 10 lb (?) That is probably a good idea to tell an operator that low fuel is happing now.
As for priming I have used the air in the tank trick to aid in priming. Dont blow up the tank. I read that a vaccume test will help or aid in finding low fuel problems. Cracked lines, holes, ect. One last thing we also blew the line out at the quick discount at the lift pump just incase there was some trash in the line or sock if it has one at the sending unit.
I have no clue if there is a way to replace the plastic seal in the quick discount at the lift pump if it is pulling in air. Good luck JimK, pm me and I can give you my number if you wont more help

 

Dude,

Your thinking about "the lp just needing to supply enough fuel to keep the VP primed" is NOT correct.

The LP is supposed to supply a little excess fuel so that the fuel can also cool the VP and then return to the tank by way of a return line, or something like that.. TO my knowledge.

Your LP has got to be dead, or you would have had fuel ALL OVER HELL when you tried to bump the starter to fill the fuel filter canister.

Ok,
Later,

 

I finally got the LP replace last week and decided to go with Walbro GFS 391 from Glacier Diesel. Confession time....Actually I thought I would buy the pump and just get all the fittings locally and save a few $$. Had to go back to Richard at Glacier a couple of times and admit that I was having trouble trying to find the parts and should have just bought his KIT and be done with it Well, it was a good experience and I learned a lot from it! Pics are in my gallery of how I installed it.

So now I am getting plenty of fuel and don't have to worry about supply. But the truck is still not running right More to follow in a new post.