Oshkosh P-19 crash truck - no start

[RobertoGatos]

Picked up this P-19 a while back. Was barely able to keep it running up the loading ramp and onto the trailer, but over the last couple years, it would always fire up, and run well enough to move it around the yard wherever it needed to be. It never lived to idle, and ran real rough. There was also a delay between the throttle input and the engine speed.



Went to start the truck today making room for another project, and it would barely fire off, then quit. Lots of cranking and no change.

Read online the filter screen in the PT pump might be a culprit. It was pretty bad, and was barely flowing fuel. Cleaned it as best a possible, and verified the pump was sucking fuel, because it would consistently fill the primary fuel filter, and the PT pump fill plug was always full of fuel.

I'm wondering if the injector lines need to be bled? Funny thing is that its never ran out of fuel. Any other ideas to help get this thing fired? I feel like there is a fuel restrictions somewhere, but am new to the PT stuff. *Think* the A1 and older 5tons used this pump also? Any experts here?

 

[Swamp Donkey]

Nice truck! If that pump uses the same screen filter as the NHC250 pump, and you'd like a new one, I'll send one your way in exchange for more pictures.

 

[RobertoGatos]

Nice truck! If that pump uses the same screen filter as the NHC250 pump, and you'd like a new one, I'll send one your way in exchange for more pictures.

Think it does, really appreciate it!

 

[162tcat]

Probably has an air leak in the fuel lines before the pump or injectors are clogged or out of adjustment.

Does it smoke while turning over or nothing?

 

[RobertoGatos]

Probably has an air leak in the fuel lines before the pump or injectors are clogged or out of adjustment.

Does it smoke while turning over or nothing?

I get some white smoke on occasion. Cant find any fuel leaks, via pressurizing the tank.

 

[USAFSS-ColdWarrior]

Ran this by a very close friend who is supervisor of the firetruck maintenance shop at Goodfellow AFB - home of the all land based DoD & all service branch firefighter training..... He echoed the fuel flow or air leakage concerns as your first step toward locating the problem. Said if the truck had been here it would not have been surplussed for such a curable problem.

Looks like a good score on your part.

 

[RobertoGatos]

Ran this by a very close friend who is supervisor of the firetruck maintenance shop at Goodfellow AFB - home of the all land based DoD & all service branch firefighter training..... He echoed the fuel flow or air leakage concerns as your first step toward locating the problem. Said if the truck had been here it would not have been surplussed for such a curable problem.

Looks like a good score on your part.

Thanks! Going to dig into it more today.

 

[NovacaineFix]

I have the same issue with my 818, uses the same filter on the IP and was constantly getting clogged before I flushed the tanks.
When it would clog, there was a delayed response on the throttle and it just had no power on the higher end.

I grabbed this NSN, not sure if it is 100% correct. NSN 2910-00-790-8736

Nice rig

 

[kmfcap]

I had the same problem on my P22. Different engine but the fuel lines rot from the inside out and swell on the inside causing flow restriction and eventual blockage. Hope this helps.

 

[RobertoGatos]

Swamp Donkey set me up with a new filter screen. Very generous of him. Thanks again!

After blowing some air through the new one he sent over, its looks like the old screen is trying to starve the motor of fuel, I definitely didn't / cannot clean it enough to be like the new one. Think I should be straightened out after swapping the new screen in.

 

[WillWagner]

If there is debris in that screen filter, there could be other issues. the filter before the pump is a smaller micron rating, so, if there are chunks of something that is not mold/moss/algae, you need to look at the pump. That screen is there so IF the pump comes apart, pieces parts don't make it to the injectors. It does make a good roost for the microbes that grow in diesel and it will clog with what looks like mud.