m939a2 wont start after fuel filter change

[captain]

I started the truck a dozen times today. It always fires up instantly. The last thing I did was change the fuel filter. I primed it for some time with the primer on the lift pump and the truck will not start. Does not catch either. I cranked it for some time too. I took the new filter off and it is full of fuel. The truck will run on either. I spent a few hours looking for a solution on here but did not find any. Is there something very simple I'm missing here?

Thanks.

 

[porkysplace]

Did the emergency shut-off lever get moved ? It needs to be re-set by hand.

 

[captain]

I've never used the shut off lever. I will look in the TMs to see how to reset it just to be sure. I have no idea how I could have hit it while changing the filter though.

 

[1 Patriot-of-many]

When you primed it you opened up the bolt at the fuel pump till fuel came out?

 

[captain]

I did not. That is something I have never had to do on my 5.9. With as similar as the 8.3 is to the 5.9 I did not think that was necessary. I can try that tomorrow.

 

[M35A2-AZ]

You need to open the vent bolt on the back of the pump to let the air pocket out.
It is the little bolt looking thing on the motor side of the pump, a little more then 1/3 of the way back from the front of the the pump,
it takes a 10mm wrench.

 

[captain]

Thank you. I will try that vent bolt tomorrow. Do I just loosen it and prime until fuel comes out?

 

[doghead]

The Proper priming procedure is in the -20 TM.

 

[M35A2-AZ]

Thank you. I will try that vent bolt tomorrow. Do I just loosen it and prime until fuel comes out?

Yes, for the most part try to get fuel out.

 

[1 Patriot-of-many]

You need to open the vent bolt on the back of the pump to let the air pocket out.
It is the little bolt looking thing on the motor side of the pump, a little more then 1/3 of the way back from the front of the the pump,
it takes a 10mm wrench.

Its on the front on the A2, in any case its in the TM as dog head noted. Correction: see M35A2-AZ post and the one following.

 

[M35A2-AZ]

Its on the front on the A2, in any case its in the TM as dog head noted.

Was trying to tell him were is was and it is not on the front side of the pump, it is on the motor side of the pump.
Or there on all the A2's that I have seen.

 

[1 Patriot-of-many]

Was trying to tell him were is was and it is not on the front side of the pump, it is on the motor side of the pump.
Or there on all the A2's that I have seen.

Hmmm..... I apologize, guess I was cracking open the wrong thing when I did mine recently. It started right up after my filter change. Thanks, sometimes the tms arrows don't really go to where it is!

 

[M35A2-AZ]

Hmmm..... I apologize, guess I was cracking open the wrong thing when I did mine recently. It started right up after my filter change. Thanks, sometimes the tms arrows don't really go to where it is!

How funny, Just wanted to clear it up for him.

 

[captain]

I cracked the line per what you guys and the TM said. Pumped and cranked. Nothing. I pressurized the tank and fired it off with either. It ran poorly but on diesel for about 30 seconds then died. The old filter was a fram the new one is a napa/wix. At this point all I can say is its either the napa/wix filter is garbage or the lift pump is dead and when it ran (like a top) before that it was pulling fuel with the injection pump not the lift pump.

 

[hklvette]

edit: nvm, forgot that tractors are different than cargo trucks.

 

[M35A2-AZ]

Do you have just the one filter on the motor or do you also have the big filter under the finder on the driver side?
You may also have a little inline filter in the fuel line just before the motor.

I have seen some of the spin on filters not fit right on the mount.

 

[captain]

Just the small motor mounted filter. no in line filters. The filter felt like it spun up correctly and mated well with block. What I cant figure out is the truck ran fine. Even sat for 6 months and fired up instantly. Then I changed the filter and all of a sudden nothing. Is it possible that the lift pump was bad and that the injection pump was pulling in the fuel? The truck was never fast (never felt like I could get it to go 55) but it would, eventually, get up to 45.

 

[M35A2-AZ]

Just the small motor mounted filter. no in line filters. The filter felt like it spun up correctly and mated well with block. What I cant figure out is the truck ran fine. Even sat for 6 months and fired up instantly. Then I changed the filter and all of a sudden nothing. Is it possible that the lift pump was bad and that the injection pump was pulling in the fuel? The truck was never fast (never felt like I could get it to go 55) but it would, eventually, get up to 45.

The trucks have no lift pump, just the Injection pump.
You may of got some dirt up into the IP pump.
When you primed on it did you get anything out the vent bolt?

 

[MO MV man]

The 8.3/A2 trucks are a booger to prime.

Mine was a living **** after changing the engine and frame filter.

You don't have a frame-mounted filter?

After thoroughly beating my head against the wall, what seemed like 100's of pumps, using some ether and getting what appeared to be steady flow at the pump inlet banjo fitting, it still wouldn't stay running.

So I put my tools down, walked away and came back the next morning.
With assistance from my brother, first try it showed signs of life!

I cracked all the injector lines at the pump and had my brother turn it over.
It chugged and chugged, and line by line it started getting fuel to each cylinder. That didn't take long at all.
Cinched down all the fittings and it's been golden ever since.

It makes me scared to death to EVER change filters again. No fun.

 

[captain]

I cracked the banjo for the feed line at the IP. I can push the primer and see fuel come out. I closed that and cracked the injector lines on the IP and cranked the engine. No fuel.