IHC won't run!

[GFMotorsports]

So I got this 1981 IHC S1854 with a DT466 about 2 weeks ago. Used it for a job last week and ran great for about 4-5 loads and during the last load I was cruising around 55mph and it started to lose power and eventually stalled out. Pulled off the road and started it back up and it went for about a mile or so then died again....after a few times stalling a dying I finally got it home. Changed out both fuel filters (they looked pretty old, filled then with diesel before I installed them), primed it and it ran for about 15 mins then completely died out and wouldn't start unless I let it sit for like and hour or so. It seems to be losing prime for sure. Looked at the main fuel line coming from the tank to filter housing and found a spot between frame and cab that looked to be chaffed a good bit, so I pulled it out and replaced it with new rubber fuel line. Primed it and it started and idled for about 10 mins and stalled out exactly like before. Decided to bleed air from bleeder on top of filter housing and a lot of air came out, cracked all the injector lines and primed it up again. Still didn't start and noticed foamy bubbles only coming out of injectors 5 and 6 (6 had way more). So what is my next diagnostic step and anyone have any ideas off the top of there head??? Thanks

 

[willie59]

Truck has a single tank? How much fuel did you have in tank when it first happened?

 

[GFMotorsports]

I'd say about half tank, I did fill it up with about 10 gallons with a diesel can figured perhaps a crappy pick up but no different.

 

[willie59]

Not saying it's your problem for sure, but run for a few, then die, come back after a spell, will start, run for a few, then die, sounds like you may have something clogging pick up tube. Try disconnecting the supply line where it connects to primary fuel filter, then blow back through line with compressed air (be sure and take the cap off the fuel tank first). Reconnect line, open bleeder, pump with hand primer until no bubbles come out and give it a try, got nothing to loose.

 

[GFMotorsports]

I will try that tomorrow thanks for the advice. Figured it had to be fuel delivery but I'm not diesel guy!.....yet

 

[GFMotorsports]

I did notice a lot dirt in the old line when I removed it.

 

[willie59]

If (by a stroke of luck) that does the trick, might not be a bad idea to take the tank off and clean it out.

 

[GFMotorsports]

If (by a stroke of luck) that does the trick, might not be a bad idea to take the tank off and clean it out.

Yeh I definitely do that, fuel sender I think is crap anyway.

 

[GFMotorsports]

So I took the tank apart and took the stand pipe (I'm guessing that's what it's called, looks like a piece of 1/2" copper pipe with nothing on the end. Sound right?) and found....... What looks like a piece of gasket sealant about 4" long and 3/8" wide stuck right at the 90 degree angle at the top of the stand pipe. So cleaned it out and it took a heck of a long to bleed it and prime it. Got it started and it did the same thing as before stalled after 10 mins or so. Did notice that every time I unscrew the first fuel filter it hisses air like crazy. Any other ideas guys??

 

[willie59]

You still have something restricting fuel supply line GF, you're gonna go nuts until you find it, but keep digging.

 

[shopguy]

Could the hiss be suction? Sounds like a pluged vent ,will it run with the cap off ?

 

[GFMotorsports]

You still have something restricting fuel supply line GF, you're gonna go nuts until you find it, but keep digging.

I did replace the whole line with a new 5/8" rubber line from tank to filter housing. Also is there a lift pump..

 

[GFMotorsports]

Could the hiss be suction? Sounds like a pluged vent ,will it run with the cap off ?

I'm not sure but I think it does but can't recall it running with the cap off. But it still loses prime every time so perhaps a suction is possible.

 

[shopguy]

Willie does the 466 have a lift pump ? could also be sucking air there from the crankcase

 

[shopguy]

So the line goes straight from the tank to the filter housing?

 

[GFMotorsports]

So the line goes straight from the tank to the filter housing?

Yep that's correct

 

[shopguy]

I think you are hearing suction at the filter ,run it till it quits and open the cap if you don't here hissing open the line at the tank

 

[GFMotorsports]

I think you are hearing suction at the filter ,run it till it quits and open the cap if you don't here hissing open the line at the tank

I did hear hissing at the line at the tank line after i loosened the rubber line after the 90 degree elbow. Hissing for sure.

 

[shopguy]

It has got to be the vent or the pick up tube plugged ,keep going clean everything from the hiss to the fuel then back out the vent till you stop
the hissing

 

[GFMotorsports]

I will try that hopefully today. Is there a screen in the filter head or something?