Jeep won't idle and then dies

Quick background...I was out running errands, Jeep was at operating temp and otherwise running well. I came out of a store, got to the road and stopped for traffic...then the Jeep just quit. I thought I was out of gas, but still had 1/4 tank. Tried to start it and it would kick over and run for a few seconds, but as soon as it got to idle, around 700 rpm, it would just keep sinking and die. This happened about 10 times. Finally got it to stay running and got it home about 5-6 miles away.

Since then I swapped out the carb back to a known good carb since I was having some issues with it anyway...thinking that was the problem. On a cold start at home it started pretty quickly, stayed running about 1,500 rpms with the choke on, then I popped the choke off and it came down to about 700 again...then dropped off and died. I then took off the fuel filter and it's good, not clogged at all.

So basically I can get it to start...and run if its higher than idle, but it won't idle.

Before I get too far into throwing money at it...fuel pump, ignition, etc., I thought I'd get some additional thoughts here.

It's a 360 with stock intake and MC2100 carb. MSD6 ignition with stock Ford coil. Standard copper spark plugs only about 9 months old. The whole Jeep (engine and all parts) only has about 7K miles on it, been on the road since 2012.

 

I cannot help you, it happened to me and I know that there is a solution. If you changed your carb it is not the carb, except if the other one has a problem.
Concerning my Jeep, I checked one point after the other, changing only 1 parameter at a time. This is not a question of money but time, except if you have a good specialist around.

The result is that I am very happy now. Except too much fuel consumption, but I'll check soon with a specialist of the old time.

For you, it happened suddenly, so it could be the carb, if not the fuel pump. My carb was dirty and I found where (accelerator pump), then it was ok. You'll find good help on the forum. So... good luck and patience.

 

I am assuming this is the 74 360. You need to systematically check things out.. First, is there fuel to the carb? Is there spark? etc etc. Could be the coil but IMO those solid coils rarely go bad.

I have a 75, and initially had the same type of problem. It kept getting worse.. Eventually I decided to replace the sock in the fuel tank.. Turns out there was a couple of gallons of junk in the tank. I blew out all the lines, replaced the sock and filled up with fresh fuel. End of problem.

 

Mine did something similar when my sock slipped off in the fuel tank. The fuel system wouldn't stay primed. I dropped the tank, and I ended up eliminating the sock after extending the pickup to within a fraction of an inch of the tank bottom. I put an inline filter after the pickup sender. Been good so far. Those socks need a way of securing them to the pickup.

 

I just had my tank down recently, its very clean. The sock was still on, although I did extend the suction tube within a fraction of an inch to the tank bottom too, with the sock back on. It appears that fuel is getting to the carb, especially since it will run at higher RPM's. I was thinking weak fuel pump?

 

I'd be checking all the vacuum lines and connections, PCV valve, etc..

 

X2 on vacuum leaks.

 

Good thoughts on the charcoal can and other vacuum issues. I've checked them recently, but it never hurts to check them again. Never thought the canister though, I'll give that an inspection too.

 

Just went through this this weekend with my jeep. Had the carb rebuilt. Installed new see through glass filter. Tuned everything. Found a lot of junk in that clear see through filter. Pulled the tank and cleaned it good. The sock had fallen off the pickup tube so I ditched that and extended the pick up tube to the bottom of the tank. Still wouldn't idle. I started the jeep and held it at a high enough throttle with the linkage to keep it running and then took some carb cleaner and sprayed it around the base of the carb and it instantly smoothed out. So...that means I had a bad vacuum leak at the adapters or base of the carb. I'm running a webber 38 mm carb so there are aluminum adapter / base plates between the carb and manifold and the gaskets were leaking badly. I've ordered new gaskets so I'm hoping to install them this week and praying that it solves my problem.

 

The glass fuel filter can break and spew gasoline all over and catch fire. I go with steel ones for that reason.

 

Well crap Chris! I didn't even think of that. I like having the glass filter because I can see what the fuel looks like but I do see that as a concern. I will at least check to see where it's sitting on the engine so I can check to see if it's bumping on something metal that might cause it to break. Thanks for the tip.

 

Hey, I put a glass filter on my jeep 25 years ago, showed my mechanic and he told me that. Im not that smart. Just passing it along. Have fun!

 

Wix makes a plastic almost clear filter.

 

Well, maybe. Depends. The glass ones I use are mighty rugged, and it is a real advantage to be able to see what's going on.
A metal line can fatigue and crack, a rubber line can wear through... a float valve can stick open... many fuel pumps had glass domes... The filter is a small factor overall, IMHO.

Has anyone ever actually personally experienced an engine fire from a glass filter breaking?

On an engine like the F-head, it is on the suction side of the pump, so no "spewing" in any case.

To each his own.