Bleeding Cummins Fuel System

[Corley5]

I ran the old girl out of fuel last night in fact it sputtered its last breath as I turned into the barnyard.  That was lucky ;)  I was too cheap to pay 3.739 at the station in town especially when I've got some fresh fuel here at the farm ;)  The fuel light was on but the gage still showed just a fuzz under an 1/8.  I know Dee has ran it lower than that ;)   I filled it up this morning, made sure the filter was full but it won't fire.  The lift pump is working or appears to be.  It filled up the filter.  Where do you begin to bleed one of these animals ???  It's a 2002 with the 24 valve engine.  The manual says to have it towed to a dealer  :  I'm not about to do that  Yet  ;)

[Dave Shepard]

The 2002 may have a different filter housing than my 99. Does it have two bleeder screws on top? If so, open the one closer to the front of the truck. Get in the truck bump the starter so it just engages and let up on the key. The lift pump (LP) it should make a nice steady hum for about 25 seconds. If there is no hum, or it doesn't sound healthy, you need a new one NOW, as it is killing your injector pump (Bosch VP44, or simply VP). After one or two cycles of this you should have bled the air out of the filter housing. You can then bleed the VP pump at the banjo fitting on the fuel line coming from the fuel filter. I usually just crack an injector line or two, at the injector. Crank until it starts, and then shut it off immediately and tighten the injector lines. If you don't have the bleeders in the filter housing, likely, my guess would be to open a few injector lines and crank til it fires.

Checking the health of your LP is vital to the longevity of your VP. If starved for fuel, the VP will pull it's own fuel, but will not get enough to cool itself, and will fry the electronics in the  injector pump. One solution for monitoring the LP health is to get a low oil pressure switch that comes on at 5 psi or less and put it in place of one of the bleeders. Run a light into the cab, and if the light comes on at any time after you are up and running, you are not getting sufficient fuel pressure to the VP. 70% of the fuel pumped to the VP is used for cooling the pump. If you need to replace the LP, an aftermarket pump is advised, as the stock Carter unit doen't seem to hold up. I have had two LPs eat two VPs. >:(


Dave

[submarinesailor]

Dave,

Is this true for the 6.0 s that are in the Ford's also?  I have heard that it's very bad for the upper fuel pump if you run them completely out of fuel.  Don't plan on doing it, just want to know.

Bruce

[sawdust]

One of our local Dodge mechanics recommends putting an electric pump before the original pump. If the pump which keeps the injector pump gets weak or dies (they seem to do that) you are looking at big bucks for a new injector. 100 dollars is cheap insurance.

sawdust

[Polly]

    8) i like the idea of loosing the lines at the injector turn engine till fuel starts coming out the fittings retighten and try starting let us know what worked when you get it going it this could happen to me     

[stonebroke]

It works even better on tractors to crack the lines at the pump and then crack them at the injectors.

Stonebroke

[Dave Shepard]

sub, the injection systems are very different between the Cummins and the 6.0 Ford. This vintage Cummins still uses an injector pump and injectors. All Powerstroke Fords use a low pressure feed pump, about 800 psi on early Pstrokes, that feeds an electric injector that makes the injection pressure, many thousands of psi. I don't know how it will affect the fuel pump to run it completely out, as I am not entirely familiar with the setup. The problem with the Cummins is that the injector pump will pull its own fuel, just enough to run, but not cool itself. It will run at full power until it has a melt down, then it is too late. Symptoms include an intermittant dead throttle pedal, tons of white smoke at times, skipping, and low power. If someone suspects a problem with their 98.5-2002 Cummins, a scan tool will reveal a couple of "death codes", P0216, and P1641 being themost common.

sawdust, yes, it is cheap insurance indeed. A reman pump is $1800, with $400 back for your core. I have heard that just the high pressure pump on the new CR Cummins are pretty pricey too. I guess the guys running the Banks kits are finding that out. ;)


Dave

[gmmills]

  Corley,

     Dave has the lift pump issues covered quite well. I also have a 2002 and the first upgrade I did was add an in the cab fuel pressure gauge. Be carefull cracking a banjo bolt loose to bleed the system. The sealing washers are usually not reusable. The washers are steel sandwiched between rubber outer coating. I would try to bleed the line from the fuel filter to the VP through the shrader valve on the banjo fitting.  Look for the black plastic valve stem cap. Just take off the cap and depress the stem while cycling the lift pump. That should bleed the system to the VP.  If it still doesn't start then crack an injector line. There is another note of caution involving the retightening the injector line. Just tighten them enough so the don't leak. Over tightening the line nut can damage the injector tubes that run into the valve cover.  Torque specs on the injector lines are 28 ft.lbs. For the banjo bolts 18 ft.lbs. 


Dave,

   The fuel filter is different on an 02. It drops in the canister from the top and has a plastic cap. No bleeder screws on top.   

[Dave Shepard]

gmmills, that is what I thought, don't know why they did away with the bleeders, maybe because you always seem to have to crack the injector lines anyway. I had no luck cracking the fuel line at the pump, it's straight to the injector for me now.


Dave

[Corley5]

Got it running this afternoon.  Cracked the banjo bolt on the supply line at the injector pump and let the LP bleed out the air there.  Still wouldn't run so I repeated that procedure and then cracked injectors 3, 4, and 5 and then 1.  Six is inaccessible and 2 is behind the coolant manifold.  Maybe with a very straight wrench two could be bled.  Kept cranking it with the starter intermittently so as not to burn it up and it finally caught and ran  8) Tightened everything back up and  didn't see any leaks after it it ran for almost an hour so I think it's good   8)  I went through the injector pump lift pump routine a while back.  Luckily it was still under warranty.  Both pumps needed replacing.  They put in new style LP that was supposed to be better  ???  Hope so anyway.  Thanks for the help guys  8) 8) 8)

[Dave Shepard]

I have half an open end 3/4" wrench for removing the back injector lines. ;)


Dave

[Corley5]

How do you get your arm to bend that way  ??? ;D   I can see the injector back but there's not much room 

The 3150 JD we used to have at work was nice to bleed.  Just crack the supply line at the pump and roll it over with the starter.  It'd pick up and run no problem.  Never had to crack an injector on it.  We had a B*#*# of a time with our 401 Case tractor this past summer.  Finally snorted her up with ether.  Knocked like H#*# for a few seconds but it worked.  This is not recommended  ;) ;D

[gmmills]

  Greg,

  Glad you got her running. Was the upgraded lift pump you had installed under warranty relocated in the fuel tank ?  If so, I would still be monitoring the fuel pressure. The jury is still out on the in the tank pump upgrade.

  Dave,

     The change in the filter housing was to make filter changes easier.  : : Drop the filter in to the canister from the top and carefully screw the cap back on.  My old 1991 12 valve had a spin on fuel filter. Just fill the new filter with clean fuel and spin it on.
No bleeding involved. I really liked that system. Quick, clean and easy.  

[Corley5]

The new pump isn't the tank.  It supposedly has a different check valve in it so fuel stays in the pump when the engine is off.  The old pumps would lose their prime which contributed to their short life span.  That's the line they gave me anyway  ;)

[Corley5]

Where would I plum into the fuel system for a pressure gage?