I have had trouble with my truck being hard to start after it sat for a while over the last month or so. But when it started it ran fine. I figured it was sucking air into the fuel system. Now the truck won't start at all. After breaking the number 1 line at the injector lose just a little fuel dribbled out. I then loosened the banjo bolt on top of the filter on the inlet side and although the lift pump was running no fuel (the lift pump sounded like crap, I'm assuming because it was running dry). Is it possible for the pump to run but not provide enough suction to del. the fuel? What approach would you take to track down the problem. What does the in tank module do other than have a sending unit for fuel level? I know from everything I read the IP is probably shot, but is there a system of steps I can take to rule out the other possibilities i.e. replacing fuel lift pump, dropping the tank to get to the module and blowing out fuel lines to the filter. Some other info I change the fuel filter every 7500 miles and also the temp here is in the 70's. Thanks for any input and advice. Bestweld.

 

your lp is dead, get a new one, prime system and, then try to start. Hopefully the ip is not dead, but it has been damaged with no lp.

 

Welcome to DTR!

Start with the MOST basic - do you have fuel? Rule of thumb (for many) is to not run these things below 1/2 tank, helps to keep a big reservoir of cool fuel to pump to / through the VP (one of the prime killers of the VP is OVERHEATING, often caused by a lack of fuel being pumped through it).

I agree with Copenhagenjunkie, sounds like you are not moving fuel with your LP - either due to a bad LP, a plugged suction tube, or....no fuel in the tank!

Is the CEL light on? If so, Autozone will read the code for free, you could have a LP and / or a VP code lurking around in there.

General ideas for troubleshooting a fuel problem (FAR too common on these trucks )

Do you hear the LP run when you bump the starter? It should run for around 30 sec. when you kick it over for a second.

Are the battery connections and grounds all clean and tight? I've seen many posts where a good cleaning of these has performed a miracle on a dead truck.

Fuel pressure is CRITICAL on these trucks -if you do not have a gauge, strongly recommend you get one so you can see what the LP is doing, and hopefully catch it before it ($150-ish) kills your VP (~$1400-ish). If you don't have one on board, you can set up a test port on the VP side of the fuel filter, put in a Schrader valve so you can see if you're pressuring up while the LP is running; There is an alternative flow-rate test, see what your pump puts out in a set time, but i am not sure of what the value needs to be.

Let us know of your progress -

Rauschbo

 

I took the lift pump off and ran a line from it into a can of diesel, then added power. The pump ran, but did not pump any fuel. I am going to buy a new pump today and see what happens. Does anybody know who sells the Holley pumps? I have not been able to find them and my local parts store wants $200.00 for an OEM pump.

 

If you can go to cummins to get the oem pump, do a search for campaign pump on here to get the correct part number. Just tell cummins parts person the part number. Holley can be bought at most parts stores.

 

I appreciate the all the help. I called Cummins and they have one for $150.00 so I'll get that today. Every one I've talked to said that my pump is more than likely ruined. How hard is it for someone to change the pump themselves? I dont mean phyisically but technically. I know you need a gear puller which I have and I have most all common tools. What are the specialty tools needed if any and is it feasible to do yourself or should it be left to a shop to do. They all want around $800.00 to $1000.00 labor around here.

 

Put a new fuel pump on today and after priming the system and about 30 sec. of cranking it started up. I put about 75 miles on it and it did fine. Do ya'll think the IP is soon to go? Thanks to those who helped Bestweld.

 

Crapshoot.
Kinda depends on how long your lift pump was dead, but then again could have no correlation.

You're already ahead of the game by replacing the lift pump before the VP44 was totally shot.
At least you'll have time to squirrel away some $$ for when the VP44 finally dies.


phox