Starved for fuel or something else?

[JKLNHYDE]

Had the truck out today and had an interesting issue that I couldn't figure out. Unfortunately, I don't have a video of it so I'll do my best at describing what it was doing.

To start, it was about 40 degrees out. After it got up to temp(or what I thought was warm enough-the head was pretty warm to touch), it wouldn't rev close to even 3/4 throttle. It was good on the low end, like right from the punch of the throttle. But that was it. It would very quickly begin stuttering and wouldn't gain any rpm. It would continue to do so until I let off the gas. And trying to adjust the HSN did nothing to stop it. At first I thought it was not getting enough fuel but the tank and line was full and bubble free.

What could be causing this?

 

[maximusraylius]

sounds like you need to ritchen up the lsn... then retune the hsp till it has good rpm. and then retune low speed till it has a nice crisp punch to it ... sounds like lsn is off and the high speed needles lean .

 

[JKLNHYDE]

I just found a #5 plug in my stash so I swapped that in. Tomorrow I'll try your suggestion Max..Thanks!

 

[maximusraylius]

np... just sounds like its needing retunes .. id start flush on lsn. then adjust high speed then go back to lsn once high speeds good ...

 

[JoeGuam]

Scott if you want I can take a look at it on tuesday. Its probably lean. We are talking about the 4.1 correct?

 

[JoeGuam]

Reset all your needles to stock setting. If it is the 4.1 set the idle at 1mm, fill your tank only half way (just enough to get your engine to temp) warm up the engine with the truck on the ground (cover the head with a sock or aluminum foil), bring it in and let it sit for 10 secs then pinch test the fuel feed line to see if your LSN is set properly. (While pinching it ) If the engine idles approx 3-4 sec with the rpm increasing only a tad and then dies then your set. If it dies automatically the LSN is lean or if it stays idling for a longer time than the 3-4 seconds then your LSN is still on the rich side.

Once the LSN and Idle set go after the HSN and start leaning. Watch your smoke trail and do not get fooled by the cold.

 

[JKLNHYDE]

Reset all your needles to stock setting. If it is the 4.1 set the idle at 1mm, fill your tank only half way (just enough to get your engine to temp) warm up the engine with the truck on the ground (cover the head with a sock or aluminum foil), bring it in and let it sit for 10 secs then pinch test the fuel feed line to see if your LSN is set properly. (While pinching it ) If the engine idles approx 3-4 sec with the rpm increasing only a tad and then dies then your set. If it dies automatically the LSN is lean or if it stays idling for a longer time than the 3-4 seconds then your LSN is still on the rich side.

Once the LSN and Idle set go after the HSN and start leaning. Watch your smoke trail and do not get fooled by the cold.

Joe,
Yeah, it's the 4.1. I did try to richen the LSN a litte but I guess I didn't go far enough out before pinching the fuel line. When I did, it stalled immediately so it must be too lean. I will be going back out tomorrow to try this. I did have a sock on the head too but it felt pretty hot so I took it off. Maybe I just need to adjust the position of the sock the head some. Thanks for the tips. I'll let everyone know how it turns out tomorrow.

 

[JoeGuam]

I ussually have it fully covered until i get it up to 200F then I half-1/4 mast it.

 

[JKLNHYDE]

So after a good two hours of outstanding run time...I experienced carnage of the worst kind..

I did exactly what Max and Joe said, set it back to factory carb adjustments and did a full retune. Worked like a champ artyon: . Got the LSN set (it was pretty lean looking back at how it was now), set the HSN for the second time and it wound up nice and just how I think it should. Still a nice trail of smoke so it must have been set pretty good.

Now, about two weeks ago I ran it briefly trying to dial in the 3 speed to my 4.1 and the gearing I was running so I locked 3rd in tight so it wouldn't grab 3rd, trying to get the 1-2 shift set. Well today after getting it tuned solid, I backed off the 3rd gear screw and started setting it. Got it :rock1: . Good to go!

Back to hitting the jumps...

Well, stopping for a few minute to top off the fuel and get a drink, I failed to release the fuel tank pressure and it ended up flooding the engine with fuel so the first time I cranked it, it killed the glow plug. :cussing: If it isn't one thing, it's another.

Swapped in a number 6 plug as it was the last one I had, adjusted the HSN a bit and away I went...about 10 minutes later..during a mid throttle run, it just clicked loud and stalled...:mushroom:
Broke the short shaft off the end of the crank that the connecting rod connects to. Time for a new mill... :dmt:

 

[maximusraylius]

ouch... my bro inlaw just did that exact same thing to his .. only second time seeing the crank pin sheer off rather than the conecting rod go out .... bummer.... but atleast you get to upgrade it now ..

 

[Mickey]

i had the exact same thing happen to my s25

 

[JKLNHYDE]

Considering I was going to build a truck for my daughter when I get back from deployment, I may just get another stock 4.1 or a 4.6 for hers now...and get the P3 for myself and the XL...

 

[JKLNHYDE]

And another picture... snoopdogg