Wont Stay Running, What’s The Issue

Hello,

I have a cj5 with the f134 and it won’t stay running. With almost full choke it’ll fire up and run, though it doesn’t sound smooth at all. Let off the choke at all and it dies. It’s got a newly rebuilt carb by Kaiser Willys, *supposedly* a new engine rebuild too. Compressions are about 110 on 1,2, and 4 and about 105 on 3, which isn’t good for a new rebuild but I figured it should still run. At TDC, cap is pointed right at cyl 1 and I triple checked the firing order. All spark plugs are sparking though they’re all black as it’s been run super rich. Also has a newer fuel pump, which is working but I was unable to test the output because my manual says to have the engine at idle for a minute, which it won’t do. Does anyone have any ideas on what the issue might be? Could it be anything internal? I’be exhausted the things that I can do with my current knowledge so any help would be greatly appreciated, before I get more upset and rip the dang thing out for a Buick v6 swap!!!

 

I would do this, if it's an actual option for you.

 

It sounds like a carburetor issue to me.

It does not sound like an ignition problem, nor would I worry about the compression readings just yet. If the engine is really a new rebuild it may not have been run long enough to seat the rings yet.

Running with the choke fully closed accounts for the rich mixture fouling the plugs.

Check the simple things first, and I am sure your issue is going to be a lot simpler than doing an engine swap.

The air / fuel mixture has to be right. You could have a vacuum leak, check to make sure the carburetor is seated and the bolts tight, check to make sure there are no open vacuum fittings. If you don't find a vacuum leak, adjust the mixture screw by screwing it all the way in then backing out 1 1/4 turn to start with, if that don't make a difference unscrew and remove mixture screw (needle valve) and make sure the passage is clear by blowing it out with compressed air, screw it back in and adjust as before.

If the above doesn't help, the issue may be with the metering rod adjustment.

Here is a Youtube which covers adjustment of the metering rod.

 

What carb are you running, Carter, Solex, ? Yes, this sounds like a carb issue, but knowing what you have might help.
-Donny

 

Donny is right. Sorry I didn't ask that question, I keep forgetting there are other carburetors sold for the F134 than the Carter I assumed you would have.

 

I'ld also be checking for vacuum leaks. Get it running and take an unlit lp torch to the carb base and throttle shaft.

Post up pictures of all your linkages and feel the throttle shaft for play.

 

Start with the simple things. Carb mixture screw set to basic spec? Look for a loose vacuum hose or a leak at the carb base. Possibly crud in the float valve or the float height is incorrect or sticky. Water in the gas in the float chamber? (Seafoam additive sometimes works magic.)

Fuel pump output can be roughly estimated as adequate if you at least verify that flow and pressure are present the carb inlet.

A "new rebuilt" carb is no guarantee of anything - just the opposite IMHO. (Rebuilt YF carbs have been known to be missing the accelerator pump check ball or weight, which are easily lost.) But I would not mess with things like the metering rod unless you are an expert, and have checked everything else first.

Work with the basics in a calm progression or you will be chasing your tail.

 

Carter, sorry! I bought a Solex and tried that one out, but it wouldn’t run right with that one either.

 

Okay I can do that! As far as I know the only vacuum lines are down to the fuel pump, and then from there to the wipers. All new lines, so those shouldn’t be leaking unless I missed a line entirely! Not sure how to describe it, I’ll post a picture soon, but below the carb the vacuum line that goes to the pump also has another port that is plugged. Not sure what that’s for?

 

Yes sir, I meant rotor. Whoops! And yes I did, I also redropped the distributor and verified it was in there correctly.

 

I popped the top off the carb the other day, and everything looked really clean. And the accelerator pump is working, trust me (I shot it in at myself testing it with the top off LOL). Would a missing check ball or weight mean that the accel pump would be INOP? The only thing I checked was for cleanliness and the float height, both seemed okay to me.

 

Thank you for the video! I’ll try pulling the mixture screw, blow it out, and set that to spec.

 

Here is everything I have for the YF.
https://flic.kr/s/aHBqjA9jxK
I think you need to get a vacuum guage on the manifold where the line heads to the fuel pump. Don't tee just replace the line with the guage. Take a video and post via YouTube link.

 

That sounds like a MAJOR vacuum leak. that's where id start, not only the vacuum lines but the throttle shaft, carb mounting, and even the 2 parts of the carb that bolt together.

 

IIRC, the F-head has an offset tang on the dist so it would be quite difficult to get it 180 out. Only fits one way
Now if your not at TDC on #1.......

 

Glen,

Yes the oil pump can be installed wrong, and there were also some import distributors on the market about a dozen years ago that had the plate on backwards. However, if he was 180 off it would not run at all, just belch flames.

To refresh your memory the distributor rotates counter clockwise, so that way.