Hi folks,

1990 , was hard starting this fall and then would not start at all. Got parked, time to fix it now. Had put a new fuel filter on it but that did not help.

When I fill the fuel tank clear full, it would leak some at the top of the tank, need to check that out.

Tonite I tried to prime with the lift pump and the lever moves but feels like it does not do anything. Bleed screw was open. Turned the motor a few times with no help.

Even if I have an air leak at the tank and no fuel at the pump, the pump should have some springy resistance, correct?

Sure sounds like the lift pump. Any opinions?

Troy.

 

You tried the lever with the engine in several positions, yes?

It should be a little springy, it will flop loosely when the arm is up on the lobe but when it's on the base circle there's a little resistance towards the bottom.

With it being a '90 I would be surprised if it didn't have a leaky fuel line. The leak by the tank is most likely the gasket, you may get away with just tightening the lock ring.

 

Yep, moved the motor several times, have to move the lever back and forth both ways by hand. Hope to get help to move it with the bumper-bar and shove it in the shed on Sat.

Have half a bed full of stuff and snow to melt and clean......................

Made a bar with a welded clevis hitch on each end to move things around, best thing ever made for free, esp. for moving something with no brakes.

 

Look at your fuel lines were they go between the frame and the tank. Check the frame for wetness. I had a bad line that was between the frame and the tank. My symptoms were the same as yours. I was lucky that I was able to see the fuel leak with the truck running.

 

The only way to be sure of the lift pump is with a pressure test. What your engine is doing would indicate a possible bad lift pump among other things, but I think it is a diagram pump and as such it should leak either into the pan or out the weep. I may be wrong but just my thoughts on it. I changed my filter once and filled the canister. I tried to finish priming with the pump and had no resistance. I must have bumped the engine at least 50 times (even set it at TDC as a starting point), and pumped the primer all afternoon. I assumed it had to be a bad pump, so I came in and ordered a new one. The next morning I went out to mess with it again and had the same results. I bumped the engine again and the pump worked perfectly (just a few strokes and fuel was gushing out of the bleeder). I thing there must be a very small area of the cam that the pump works at. At least now I have a new spare pump behind the seat.

 

Pusher/puller.

I have the once-straight coupling-pole out of a hay-wagon that shouldn't have gotten loaned.

There is a twelve-foot straight section that is destined to become my pusher/puller pole, as soon as I get time to weld on the ends.


As to your starting problem, dis-connect the grid-heaters and mist ETHER into the intake, while someone is cranking.


If it is gonna fire, it will fire on the ether, and then self-bleed.


Every brand new Cummins gets a taste of ether at the assembly plant; it won't hurt one to get an occassional snort.

 

Got help to shove it into the shed today.

Melted out the bed, plugged in the block heater, disabled the heater grid.

Played with the lift pump and got a little resistance for the lower 3/4 inch or so. Opened the bleed screw and after I blew some pressure in the tank, I could get it to pump a little through the bleed screw. Not the gush-squirt like normal, more of a small seep.

Did a one little hit of ether after it would not start, of course the battery went low right in the middle of trying to start on ether. Cough-clunk-clunk.

Get battery charger on and crack the middle 4 injector lines to bleed. Bleed. Tighten lines.

Motor started with help from throttle and ran fine for about 5 mins. Shut it off and tried to restart right away. Needed to open the throttle 3/4 open and crank for 30 seconds to get it to start. Shut it off for a couple of mins. and then it would not start, even after doing the bleed screw again.

Need to try to look at the fuel line above the tank to find a leak. Would a leaking fuel line suck just enough air to run but not restart?

About ready to go buy the new 2007 cab/chassis in the paper for $24,000 and sell all the rest! Help keep me out of debt!!!!!!!

 

Yes, an air leak will cause the trouble you are having.