New to me 58 Willy CJ5..

Here it goes, I recently purchased a 58 Willys CJ5 it drove fine the day we bought it, now it seems that when it gets warm it starts to sputter and buck then die. After a few minutes, it starts up the it will do it again. Any suggestions on where to start?? I wrapped the fuel lines I thought it might be vapor lock but no help...

 

There are a number of things this could be. The first thing I would try is to determine if it's an ignition or fuel issue. Let it warm up. When it begins to sputter, shoot some carb cleaner or fuel into the carb. If the engine picks back up you know it's a fuel problem. If not, it's likely an ignition problem.

 

" shoot some carb cleaner or fuel into the carb. If the engine picks back up you know it's a fuel problem."

Sounds more like it's running too rich already. Any black smoke from the tailpipe?

 

A couple of suggestions, base on my first hand experience with my jeep, had both problems cause what you describe.

1. Install a clear plastic fuel filter between the fuel pump and the carb. If the fuel system is ok up to the carb, then the fuel filter should fill well past the halfway point, and should remain that way while the engine continues to run. My experience was that the tank had a lot of rust, and the engine would initially run ok until I drove it a half a mile, at which time the rust would collect on the pickup screen on the tank and plug the screen, and thus the fuel wasn't getting to the fuel pump. You could watch the fuel filter start out full, and then the fuel pump would suck air and the fuel filter would appear nearly empty. There is a filter screen in the fuel pump, as well, which was nearly filled with rust. Ended up cleaning and reaplying tank liner to the tank, rebuilding the fuel pump, and replaced the fuel lines. Another thing, is old gas tanks can lose their linings, mine came of in sections that looked like decomposed leaves. Today's fuels have a 10% alcohol, which is harmful to the fuel system. I use a small 2 qt gas tank from a small engine to trouble fuel tank problems.

2. I had a headgasket which leaked fuel into one of the cylinders. The symptom was that the engine would run fine until it warmed up and the cooling system built up pressure, which pushed a small amount of water into cylinder. Turns out the engine would'nt exhibit the problem if I left the radiator cap off, since the cooling system wouldn't build pressure with the cap off. Certainly not a fix, but might get you home in a pinch.

3. Also check the ignition points. If they are burnt, they may work fine when the engine is cold, but the poor connection from the burnt points heats up and increases resistance, causing the engine to sputter and stall.

You'll get to learn about troubleshooting with an old jeep.

Good luck

 

I will try it.

 

@ PeteL
no smoke at all.

 

Diggerjeep, did you mean "coolant" in item #2 rather than fuel? I have experienced that problem but the symptom was that after sitting it would miss on one cylinder until it dried out. Taking the radiator cap off at night worked.

58, Another thing to check is that the gas cap vent is working. After it stalls out, if you pull the gas cap and there is vacuum in the tank you have a problem. Or try running it with the cap loose.

 

No luck with the fuel cap, I took it for a spin with the kids, after about 10 min of warm up then 15 min of driving around the block, it died once, I tried removing the fuel cap, no vacum.

Thank you Gentleman for the help this far!

 

The fuel filter( placed between the tank and pump, PO ) seems to maintain the half way mark and is flowing clear. Are air bubbles natural within the filter housing?.

 

Bubbles are normal.

Another odd thing that can choke an engine is a blocked exhaust. Squirrels filling the muffler with nuts, etc. Ask me how I know. Or a bent pipe, bad muffler baffle, etc

An engine (manifold) vaccuum gauge may be helpful in analyzing this problem. Not expensive.

 

Now that I looked, there is a dent in the exhaust pipe past the muffler, looks like possible rock damage??

 

,


Yes, I meant leak coolant into the cylinder. Sorry for the confusion.

Thanks for catching that.

 

You shouldn't have air bubbles once the fuel line between the tank and fuel pump is full of fuel. I suspect that you may be cucking air into the fuel pump around the fuel bowl gasket or center bolt that holds the fuel bowl to the fuel pump. It is easier for the fuel pump to suck air than fuel if there is a place for the air to get in. Also check the integrity of the flexible fuel line which goes between the steel fuel line and the input of the fuel pump. It it is old and cracked, it is a place where air can get in.

I keep a piece of flexible magnet which I got out of a refridgerator door gasket in my garage. I use it to test fuel tanks for rust. The magnet is 3' long. I put it down the mouth of the tank and see how much rust I pick up. You could also use one of the magnetic business cards, which may be easier for you to come by. Punch a hole in one end of the card and tie it to a yard stick and put it down the mouth of the tank. (Half of a yard stick makes for a handy fuel guage )

Your tank should have a drain accessible fromt he underside. The drain is in a somewhat of a dimple (outward, forming a small bowl). Before you try to remove the drain plug, spray with PB Blaster to assist in the removal. Be sure to grab the outside of the bung with a pair of vise grips, or you may very well twist the bung out of the tank before the plug releases from the bung (been there, which I had not twisted the bung out to learn this). On my tank there was so much rust in the bowl, that the fuel wouldn't drain.

 

The glass domes on my fuel pumps always 'bubble" without any obvious reason, or harm done. I think it may just be vapor bubbles generated on the suction stroke, especially with modern "clean" fuels that have added ingredients to increase their volatility.

 

Maybe to simplify it a little bit more on the search for fuel and spark-

When the engine is cool, pull the air cleaner off and open the throttle at the carb while watching to see if you have a good accelerator pump shot. If you do, run it until it gets hot and stops, then check for accelerator pump shot again. If it still has a good pump shot, then it is likely not a fuel problem.

Pull a plug wire and see if you have a good blue spark while cranking. If not, check the points as suggested above. More likely, I would guess, is a coil that is breaking down when it gets hot and starts working again when it cools down, but...assuming can cost money.

 

After looking in the fuel tank, lots of stuff moving around!

 

So, after pulling the tank, draining it of fuel, I have found alot of rust and sludge. I am going to try cleaning it out, cleaning the fuel lines installing a new coil, plugs, wires, rebuild Dist., gas cap...... lets see if this works....

 

Try doing one thing at a time, or you will never know what it was...

 

Will do, like a little kid, can't wait to drive it!