Yes, i know there's alot of threads on this but i haven't found anything helpful so i thought i'll try here.

So, i changed the fuel filter on my -97 5.9 cummins diesel and since then, it's not willing to start most of the time. It feels like there is air trapped somewhere but i need to figure out how to bleed so it goes away.

The truck has always started on "starterspray" since the filter change. And then as long as i drive it a couple of times/day, it runs fine. But if i leave it for a couple of days, it wont start.

I have a manual primer "button" that is located below the fuel filter on what i assume is the liftpump? If i press it, i can feel that it's only air there. I have tried to bleed on top of the fuel filter while priming, with no luck.

Of course i have bled the injectors and filter while the truck is running.

What bleedscrew should i open when priming or is there something else i should do?


Edit (problem fixed):

So i thought that i could write the whole story, hoping i can help somebody with the same problem since i couldn't find anyone with the exact same problem as me.


So it began after the filter change, it would not run, took 3 hours and a whole lot of starterspray to get it running. Then i thought everything was OK, even though i could not prime the system with the mechanical liftpump.

But after that, 80% of the times i wanted to start it, i had to use starterspray to get it running. After days and days of googleing, i thought it can't be anything else than the LP. So i ordered a new LP (took the cheapest one on ebay). I then searched for instructions on how to change it since it is mounted on the engine and found a very proper instruction, BUT it seemed kind of advanced, so i just skipped that one and went my own way.

NOTE: mine is lifted about 6,5'' so i did all the work from the tirehousing, it is probably alot trickier from the top of the engine. Small (very small) hands is a big + when doing this.

So, the first thing you need to do is loosen the fittings on top of the dieselheater, which is located on the left together with the LP, then loosen the LPs fitting on top going to the fuelfilter. My fitting on the LP was worn out so i had to loosen it on top of the filter instead, just a bit trickier to get the stuff out of the engine.

Then i carefully loosened the two bolts that hold the LP and dieselheater in place on the engine. IF the camlobe that runs the LP is engaging the LP, i would advise you to rotate the engine (bump the starter). It will be easier to remove and install the new LP later. So once the bolts is loosened, carefully (!) take out the LP together with the heater so the pin in the LP doesn't get stuck somewhere in the engine, then it will fall in and you have just added several hours to your workingtime. Now you can either take out the heater and LP upwards or downwards. I had to take it downwards since i had the fuelline still connected on the LP.

With the LP that i bought, it only contained 1 gasket, but you need 2 IMO. So i bought "gasket on a tube" and smeared it like everywhere. I put the gasket that was included between the heaters mount and the engine block.

Now that you have the heater out, screw it open and clean the filter inside and put a new oring in it. When you have put the heater and LP together again, it is easiest to drop it from the top of the engine by the filter to get it somewhat in place.
Now this part got a little tricky for me, i got 1 bolt to engage in the engine (only put it in like 2-3 mm) but the other bolt (on the right side of LP) took me 2 hours to get in. I think the camlobe was slightly pressing on the LP. Don't screw in one bolt at a time, take turns, a few mm at a time per bolt. Then simply put the fuelfittings on the heater and LP back on.

After this, i tried priming the system with the bleedscrew on the filter (like stated later in this thread, i pushed it like 500 times and nothing happened), but it wouldn't work. So i tried to crank it and suddenly it was diesel all over the place, guess the camlobe was in the wrong spot again.

So now i had diesel to the filter but it would still not start. After hours of searching i found a bleedscrew on top of the IP, on top towards the engine, opened it and priming manually until diesel came out. Still no start. The fuel valve would not open, loose cabelshoe by the relay, must've loosened it by mistake when dealing with the LP change.

Hope this will help somebody, it would've helped me alot anyway

 

Nobody has a clue?

Btw, i have seen some videos where they bump the starter and the liftpump starts running about 20 seconds, so you can bleed with pressure that way, is that only on newer models?
I have never heard the liftpump running after a starting attempt?

 

Not familiar with the diesel. So, no, i dont have a clue.

 

Yes, you do probably have an air pocket. There is a bleed procedure for them, but I'm unfamiliar with the 12v trucks, and my 24v has an aftermarket lift pump and filter setup.
Did you prefill the filter before it went back together?

 

Download the service manual from here, read the service procedure for filter change.

 

If you had it running, the air should've been pushed through. It sounds like you have a leak in the suction line, either at the filter, or somewhere else. When you shut it off, fuel is running back to the tank as air is leaking in somewhere. My guess is you didn't get a good seal at the filter. Did you make sure the old gasket was removed? That is where I would start.

 

Yes i even filled it up through one of the bleed screws on the top of the filter.



Can't seem to get the manual to work, but probably just something wrong my computer, says the pages wont load. Have to check later somewhere else.

Well, the return line accidently broke during the filter change but i'm like 95% sure that got sealed properly. And even if there is an open return line, it shouldn't matter right?
About the filter, the new gaskets looked the same as the old and yes i removed the old gaskets.

But even if i find a leak and fixes it, how am i supposed to prime the system to get it running again? Not so fond of using starterspray.

And even if i have a leak somewhere around the filter, there shouldn't be any air in the manual primerbutton right?

 

Forgot to mention, the last time i had it running, i checked to see if there were any diesel leakage, and i could not find any.

 

So i tried doing it according to the manual, open bleed screw on the line that goes to the pump and press the primer button. But it doesn't seem to work, i have pressed for several minutes over and over but it's nothing but air..

Any ideas?

 

Got a leak in the line somewhere, that it is drawing air, and not fuel?

Is the filter sealed up good?