Starting new thread for same old problem.....

[USMC 00-08]

It's real nice to see everything on one thread instead of adding a new thread for each challenge. You're much easier to find all on one thread.

This!!

I think your truck needs it's own dedicated thread Brad. Complete with pictures of that beauty.

 

[Brad]

Anything is worth a try.

 

[Brad]

It looks to me that I sort of do have a dedicated thread for this truck, up to 4 pages now. This truck was a dream of my Fathers. He had two of these and this was the best one of the two. After he used them for some hobby logging work after he had retired, he offered them to the local American Legion and VFW to restore and use for hauling veterans in parades and such. They wisely declined as being too much work. So Dad and I and my Brothers all pitched in and got this truck together. Dad got to ride in two or three parades, he was a wounded Korean War Vet, Inchon and the Chosen. #2nd RCT, 7th Div.
He passed in 2010 and we gave this truck to my youngest Son, an Iraqi War veteran. What we gave him was a big job, and a super pain.
We been running it as intended ever since. This spring I bought him 6 new tires and tubes as I was very concerned about the old tires that were on it. Soon as we did that, these troubles began.
This is just too much for me to allow my Son to deal with alone. I am 72 and tired of working on this truck, off and on for 20 years or so now. But I do all I can for my Dad and my Son. But I am about at my limit. I just do not know what to do next, and have spent enough money guessing.
Thanks to all for everyones help and suggestions.
Here are a couple pics. We usually ride the Westmoreland County Viet Vets, but all are welcome.
That is Dad with his truck, about 2002.

 

[USMC 00-08]

That is a good looking truck!

 

[Jbulach]

I haven’t went back to reread everything, but are we sure there is not some junk in the fuel tank, that is sucking up and blocking the end of the fuel pickup tube, or do these trucks have a sock on the end of the pickup?

 

[Brad]

I am pretty sure the fuel lines are open from the tank to carb. All new lines, new elec fuel pump, new in line filter. Even tried it without a filter. The rubber lines had been 1/4" for 20 years, even upsized to 5/16 when replacing.
The tank looks clean as a whistle inside. We had it cleaned and coated about 20 years ago.

 

[biscuitwhistler37]

That could be the issue right there. If that fuel pump isn't pushing enough volume through the bigger lines, it'll cause it to starve until the pump catches up, which would explain why it immediately fires after stalling; she's not drinking and the pump catches up.

What pump did you use as a replacement?

 

[USMC 00-08]

Brad, I sent you an email with the carburetor documents, but here is a link to them that we uploaded here.

HOLLY CARBURETOR, MODEL -- 885 - FFG -- TM 9-1826D

I received today three PowerPoint series of Description, Disassembly and Assembly. Thanks to @USMC 00-08 for downloading them and passing them along!

www.steelsoldiers.com

 

[msgjd]

I was parked beside a pretty rare jeep one time that had some real nice paint and canvas on it. The NEW rule was never to park on the exhaust side of a deuce because they may spit black soot on start up.

one of the things we did in the motor pool to FNG's (or each other if one of us forgot) was to start a 5-ton when the guy sitting in the truck to your right had rolled his window down .. Guaranteed to spit watery soot all over a clean uniform .. yeah, we could be mean but it was a lesson-giving fun kind of "mean"

 

[msgjd]

This may have been tried, but go for a run with the gas cap off.

Sounds to me like whatever is used to admit air into the tank as fuel is drawn off is causing a vacuum the pump can't overcome.

Just a thought...

Good call !! i had a CJ that did that once , kept dying out until i jerked the wheel and sloshed the fuel around.. the cap vent had a restriction ...

Brad's jimmy fuel tank likely has the vented cap with the selector lever inside .. It might be turned to "off" .. Man, why didn't i think of that>????

 

[williamh]

That truck should have a non vented cap. but should have a vent line to the air cleaner. No way it’s jumped time. It would star barking fire out the carb when trying to start. If it will start and run for 20 min. at idle without dying , it shouldn’t be the coil. But die under load ? That sounds most likely just a fuel delivery issue. Vapor lock or bad pickup , pump. It’s easy for me to say. Just get a 12v pump and run a gas line from a 5 gallon jug to the carb. I’m having a similar issue with my funvee , will sit and idle all day long but put under a load for 5 min. Truck dies. Replaced the filter , pump and it’s got a full tank. But when it starts to die I jump out and open the drain on the filter and nothing comes out. I’ve replaced the rubber lines and no change. Now I’m going to drop the tank to find out what’s plugging the inlet screen.

 

[Brad]

Thanks for all the input. In my limited expierience, I just don't see it being the coil, but my Son ordered a new one and we'll try that. As for the size of the fuel lines, the pump has 5/16 fittings, the carb has 5/15 fittings. When the guy at NAPA told me that 1/4" was for lawn mowers, it made sense to me. However the truck had been running for 20 years on 1/4" lines my Dad put on?

 

[msgjd]

That truck should have a non vented cap. but should have a vent line to the air cleaner.

i don't know which cap is original to the jimmies but the XM211 i once had had a selectable vented cap just like what's on my M51 and the M52 (gassers)

 

[Brad]

Might have made some progress today. First thing, we tried the truck with the gas cap OFF. No difference.
Then we took the all new fuel line apart at the filter, put the end back in the tank and started the truck until we ran the carb out of gas.
Biggest thing was that the NEW pump must be bad? Barely a trickle, now and then a spurt or squirt. Looks very weak to me, certainly not anywhere near a full flow.
Secondly, after using all the gas in the float bowl I was able to blow into the carb fuel line pretty easily. I had been concerned maybe a blockage in the carb.
They have NOS fuel pumps at Memphis, but just like it says, they are OLD. And only a 30 day warranty on these old pumps from the 80's and 90's. I called NAPA and they will give me another new one to try, in case the one we just bought from them is bad?
So I guess that's where we're at.
However, if that new coil should show up, we will try that in the mean time?
Do any of this make any sense??
Thanks to all.

 

[biscuitwhistler37]

I don't think it's the pump, I think it's from gaining a sixteenth of an inch in line size. So I guess technically it is the pump, but there's nothing wrong with the unit itself other than it can't supply the volume necessary to keep the truck running.

I could be wrong and it could be defective, swapping the new one in will tell, but if after the new pump and coil there's no change, I'd be downsizing those lines again.

 

[rustystud]

I don't think it's the pump, I think it's from gaining a sixteenth of an inch in line size. So I guess technically it is the pump, but there's nothing wrong with the unit itself other than it can't supply the volume necessary to keep the truck running.

I could be wrong and it could be defective, swapping the new one in will tell, but if after the new pump and coil there's no change, I'd be downsizing those lines again.

The fuel line size will make no difference here. The only way it would is if you're going to a "smaller" size.
It's a matter of "flow" .

In my crud drawing you can see the pump is exiting at a given size and the carburetor has a given size for entry. As long as the fuel line is not smaller than the exit or entry the flow will be the same. Of course, there are variables like surface friction and bends in a line but that is getting down into the "nitty gritty" which we don't need for this. Once the fuel pump has "filled" the extra space of the larger hose, the flow will be the same as the regular fuel line.
The best analogy would be "electrical flow". Putting a larger electrical wire in a circuit will make no difference as long as the input and output don't change. Now putting a "smaller" wire will create more resistance and effect the circuits operation.

 

[Brad]

My concern is that we started down this road because it was not running well, was stalling, etc. So far nothing we have done has made any noticable change. Perhaps my old pump was not bad. The truck did have 1/4" rubber lines for 20+years, and ran well. The fittings on the pump I had were for 5/16" and we had a tuff time getting the 1/4 lines over them. The ports on the newer pump were for even larger fittings and we had to bush them down.
Concerned with the very aged condition of the original rubber lines we went with all new, and the NAPA guy scoffed at my 1/4 lines and said I needed the 5/16". So since we were doing all new lines anyway, I took his advice?
I guess we'll see? He says the replacement pump will be in later today. It's specs are supposed to be 32 gal/hr, 4 1/2 to 9 PSI. I have no idea if that is sufficient? The old pump said 7 PSI?

 

[Mullaney]

My concern is that we started down this road because it was not running well, was stalling, etc. So far nothing we have done has made any noticable change. Perhaps my old pump was not bad. The truck did have 1/4" rubber lines for 20+years, and ran well. The fittings on the pump I had were for 5/16" and we had a tuff time getting the 1/4 lines over them. The ports on the newer pump were for even larger fittings and we had to bush them down.
Concerned with the very aged condition of the original rubber lines we went with all new, and the NAPA guy scoffed at my 1/4 lines and said I needed the 5/16". So since we were doing all new lines anyway, I took his advice?
I guess we'll see? He says the replacement pump will be in later today. It's specs are supposed to be 32 gal/hr, 4 1/2 to 9 PSI. I have no idea if that is sufficient? The old pump said 7 PSI?

.
Sounds to me like the pump will be just fine. You replaced all the tubing from the tank to the motor - if I remember correctly? 1/4 inch to 5/16 isn't going to matter. If you were guzzling fuel like back in the day when I was racing - yeah. That might be a problem but you won't have that problem...

If it doesn't solve the problem, get yourself a gallon can and run the motor directly off the fuel can. Tie Wrap or rope it to the fender - then go down the road. If that solves your problem there is an obstruction in the fuel line.

 

[Brad]

Going to have to try that. Do you mean just gravity flow from a can?
Another matter may be wrong. The wire from the Primary Circuit Resistor seems mighty lose where it attaches to the resistor. Would that effect the way this is running? If I remember from years ago, that resistor reduces the voltage to the points? I was raining and dark this evening so I could not see so well, but I am going to look and see if the NEW points are burned at all?

 

[msgjd]

The wire from the Primary Circuit Resistor seems mighty lose where it attaches to the resistor. Would that effect the way this is running? If I remember from years ago, that resistor reduces the voltage to the points? \?

1: the resistor reduces voltage to the coil , IIRC ..

2: it's been so long since i had a jimmy i have forgotten what pieces are in its ignition system .. On my 5-ton gassers it's regular practice to keep a spare resistor or two in the glove box because when they burn out it's all over now baby blue,, stranded .. It's been many years since i've had one fry but now that i've said that, 'ol Mullaney or Murphy is gonna strike

3: IME , resistors are either good, or burnt out , i don't think there's an in between , just like with LED lighting .. There's either a Light-emitting diode ,,, Or as i coined the opposite, a DED (darkness-emitting diode, pronouced "dead" )

4: Any loose or corroded/dirty connection is going to have an effect at some point in the game