sudden engine stalling

well i haven't posted a question for awhile so here you go!

the first time this happened i just ignored it, but it happened again on sunday so i better check it out...

i drive about 5 miles to the gas station, fill up and then head off to the hills. the first time i drove another 10 miles and then stopped to wait for a buddy. when i started up the jeep and took off the engine just died completely. restarted with a little extra gas just fine and no more problems. on sunday it died just after leaving the pump... restarted the same way and no further problems. it's weird though... full power for a second and then nothing.

any thoughts?

chris

 

Hmmm, sounds familiar Chris. What kind of distributor?

 

Check the gas filter in the carb inlet. I had a problem with that recently where everything runs fine, then won't restart after you shut it off - the float bowl was empty. I thought it was the fuel pump. Then I thought it was the needle valve sticking. Then I finally changed the inlet filter.

 

i am using the cape conversions hei setup.

i am also thinking it is a fuel problem, but since it restarts just fine and continues to run all day i am not sure what it might be.

chris

 

Maybe....I have a MSD ignition and had fiddled with the power wires....next day it just "POOP" stopped dead in the road....knew right away....the ground wire for the MSD box had come loose and lost ground. Done any work on the electrical system lately, installed lights or stereo....bad ground wire in the ignition somewhere???

Also had a worn out ignition switch one time, jiggle it right and it would loose a connection internally and the motor would shut off, jiggle again (restart) and everything is fine...until the next time! Ignition switch???

Cold be a sticking inlet needle, but I wouldlean towards electrical/ground.....

 

I Just Recently Had The Same Thing..ignition Switch Too. Mine Didn't Happen After The Fill Up Or Anything I Was Just Driving Down The Road And Like You Said...full Power And Then Dead. I Haven't Had The Problem Since, At Least Not That Problem Anyhow. Good Luck!!

 

well, all the fuel and ignition components have been replaced within the last 2-3 yrs. the carb is a reman unit about 3 yrs old... say 1500-2000 miles on it. i know i have been pushing my luck with a no-return fuel setup so maybe it is a flow issue. you can hear the tank "poping" once in awhile since it has no way to vent.

how often should the fuel filter be replaced? i suppose that would be a cheap test to start with.

i will be installing a rear underbody tank sometime soon so i will mess with it then.

chris

 

My56 cj5 was doing the same thing. It would shut off without warning. It finely got to the point where it would only run about 15 seconds.

I went nearly thorough the whole fuel delivery system before fixing it today with a new $5.00 fuel line from the gas tank to the fuel pump. Duh.


Thinking it was probably the old gas tank getting some rust in the system, I bought a new metal gas tank. Replaced the fuel pump. Put on a new inline fuel filter. And just yesterday I ordered a new carburetor kit for the solex carb.

And it still would shut off. I was beginning to think it was electrical. Today I was determined to start checking the system out. I started at the tank, removed the fuel line from the tank and also removed it from the fuel pump. I blew into the fuel line and it was totally stopped up. Must have had something lodged in it. Rust or some other type of material clogging ups the line.

Put on the new fuel line from the tank to the fuel pump, and she is running like a top.

 

yeah, my fuel lines are very old and should be replaced. i bet there is something in there clogging it up.

when i set up the rear tank i will definately run some good fuel lines and have a return.

thanks,

chris

 

i smoke so i don't think a vent right there would be a good idea! smoking with the ejector tank under me is scarey enough... i suppose that line could be run anywhere above the tank though.

my tank is well sealed and the cap seems to seal well also. i know it wants to vent but i have been putting off dealing with it since i hate working on fuel lines.

chris

 

I prefer the steel fuel lines. But if you wanted to do a quick test maybe you could get the tank and fuel pump fittings with hose barbs and run a rubber fuel line and see if that is your problem. I know I wish I had before replacing everything except the carb.

 

Yeah, you need steel lines. I don't think the return line has much effect on the venting except to reduce vapor lock. The constant flow of fuel from the tank to the pump and back keeps the lines cooler.

I'd say you can't run without a vented cap, or else some remote vent. If the tank is really sealed well, at some point the pump can't pull against the vacuum built up in the tank. The float bowl runs dry and you stop. The air in the tank slowly equalizes with the atmospheric pressure, and walla, the pump works again.

When I installed an underseat tank on my '73, I tried to connect it to the existing vapor recovery system. I drilled a hole in the top of the filler neck and put a nipple in with liquid steel. Then I ran that line thtough the floor and back to connect with the vent lines from the stock rear tank. Can't say how well it worked, because I tried to seal a vented cap with some liquid steel, and it leaked anyway. Gas would dribble down the side of the Jeep whenever I was on a sidehill - no inspection required then, so I didn't try to perfect it.

Regardless, you need a vent.