Engine stalls at higher RPM or steep grades

[Chris_M]

Hello Guys,
last weekend I took my GMC out to an event. We had a convoy consisting of a Willys Jeep, a Dodge 1 1/2 ton, a GMC CCKW 352 closed cab and my CCKW 353 open cab.
All went perfect until the event was over and we drove home. Then it happened. My Jimmy's engine began to sputter and shutted down, whenever I tried to drive faster in higher gears. As long as I was driving very slow in first or second gear, everything was fine. The engines idles without a problem and very smooth. What could be the problem? Any ideas? A clogged fuel line or fuel filter? Damaged diaphragm in fuel pump?Clogged jets in the carburetor?

Regards,

Chris

[pristus1]

i had simuler problem 1st was feul leak on diafram 2 was filter at pump side had that much sludge i dont know how it ran at all when cleaned out ran fine but also chech ruber hose that goes to your wiper mine had a hole in it hope any of this help wayne 353 lwb open cab 1945

[Gordon_M]

When you took it out you filled it up with fuel and it has washed some rubbish into the fuel system I think.

Pull and clean the chassis filter, think about some new fuel hoses. I'd be surprised if it wasn't a fuel blockage somewhere from your description of how it runs.

Might be the pump diaphragm too, of course

[hippiedude]

It could be water in your gas tank........Check it out when you check filters ............ Tim

[Chris_M]

Thank you guys,

indeed I filled the tank and it was only half filled for more than 2 years. Now the fuel system seems to be contaminated . I will check it out this weekend.

Regards,

Chris

[Capt Lee P]

Hi

Like all CCKW's owners we all have had similiar situations happen. Suggestion: place an inline disposable fuel filter right out of the gas tank where there is a fitting junction at the frame rail. As a further precaution, place another inline disposable see thru fuel filter right next to the carburetor. It is amazing what can be in the fuel tank and lines and the stock fuel filter does not always pick up the junk.

Also, check the points, distributor cap and the spark plugs.

Lee

[dr deuce]

Like all CCKW's owners we all have had similiar situations happen. Suggestion: place an inline disposable fuel filter right out of the gas tank where there is a fitting junction at the frame rail. As a further precaution, place another inline disposable see thru fuel filter right next to the carburetor.

bingo. You can never have too many filters for gas and old gas tanks and lines

It could also be the 'guvner' though most likely gas system

[Brad]

I took my truck on a small drive and noticed it wasnt driving good at all!!! i looked at the fuel pump glass it was packed with what looked like coffee grounds after that i added in line filters. it just takes a few shakes and rattles then plug....

[Grease_Monkey]

Hi Chris!

Finally managed to register myself...

Just to let you know: I took your rig apart! So don't wonder when you find your truck in pieces.

I managed to repair your master cylinder. We forgot to put in a little rubber gromet.
It was one of the two in the repair kit we couldn't figure out where it belongs.
I was staring at the internals for a while, until i realized that there's a little rubber seal around the check valve.
After putting it back together and into the truck, i had (at least) no leaks. It did not really create pressure, but i am sure once we bleed the brakes, it will be all fine.

Back to the topic:
I further took your carburator out, disassembled it and left it sitting in solvent to get the dirt out (surpricingly it was pretty much clean inside).

I will put everything back together tomorow, and i (we) would be glad if you could come, as we want to make a joyride to the "secret" pub.

See you soon
GM

[Hammerhead]

Hi Chris,
I too had this very problem with my CCKW. I first checked the fuel filters. There was some sludge so that helped cleaning that up but the problem was still there. I replaced the fuel hose and got one of those fuel pump rebuild kits from Frank's CCKW. After those were done she runs like a dream.
Interestingly, my buddy pulled his halftract out for the WWII Weekend last month. It too idled great but sputtered and died with any acceleration. We replaced the fuel lines and in-line fuel filters (all three of them) and it ran great the rest of the time!

[Chris_M]

Hi Greasy!

Great to see you aboard. Well, I think I was too fast. I ordered a new Brake Master Cylinder 3 days ago.
Thank you for your efforts, working on my truck. I hope cleaning the carb will solve the problem. As we found out. The fuel filter was clean. Just to be sure, I am going to install a new ignition coil as well. If all this does not help, although this part was installed new 2 years ago, I will have to disassemble the fuel pump.

Regards,

Chris

[oldreliable9_47]

I dont have fuel filter problems cuz I have a clean relined tank.....only thing I did last weekend is pump that damn Bio Diesel into my baby by mistake. good thing I had half tank of gas already when I topped it off..truck didnt like ti but after awhile ran fine..I do believe they will run on karosene if needed LOL

This gasoline we have today is bad..burns like karosene..dirty. must be all the guvment reg additives. I sure miss real gasoline..ya know the reddish color and that smell

[John V Cliche]

I run AV gas in all my stuff

Hope this helps
John

[Chris_M]

Well, it's been a while. Finally Grease Monkey and me found the source of the engines misbehaviour.
The fuel line between gas tank and fuel filter was clogged. Greasy simply disconnected the fuel line in front of the shut off cock and connected a rubber hose to the line. Good lungs and a strong blow into the hose quickly cleaned the line.
So, a rubber hose is one of the standard tools aboard my truck in the future.

Regards,

Chris

[snow man]

I always pour in a little Marvel Mystery Oil in the gas ...your Valves will like you for it ! I like the NEW web pages.