82 CJ8 stalling out at 35 mpg

[BubbaBull]

I am new to Jeeps in general, my Son purchased this one on Ebay a few months ago. It looks great but has an issue of stalling out when you hit 2nd or 3rd gear around 30 - 35 mph... it has a 258 in line 6 cyl and has had several mods done in the past! We have replaced the carb, fuel pump & coil. Reset the timing to 8 btdc. Next we plan to drop the gas tank and clean it out.
It starts and runs good at idle and under low rpm's but seems to be starving for fuel when you try to accelerate thru the gears...
Any ideas?

 

[Red Mutt Ranch]

Yeah you have a fuel clog probably in the pickup.

 

[TLCJ5]

I agree it sounds like a fuel problem...had a similar issue with a clogged fuel filter once...would run ok until increased load then would stall out.There's a screen on the fuel pickup in the tank that can get clogged.

 

[BubbaBull]

Thanks guys.. pulling the tank was on our list anyway.

 

[tjlboise]

Maybe the fuel pump? Sounds like the more you try to give, harder time it has getting there. I don't know. Just a thought.

 

[timmy350]

I would love to hear how it works out I'm having the same problem with 78 cj7 new carb dropped the tank brand new inside new sending unit (which I need to adjust) cap rotor wire plugs fuel filter 1st gear great 2nd good 3rd falls on its face if I put it to the floor it will cough and spit then finally get through it and ill have moderate power never had a 258 before don't know how well its supposed push 32s but this seems weak for an i6

 

[Ggg]

I agree with TJCJ5 typical clogged fuel filter symptoms.

 

[stumpbumper]

You are probably on the right course but here is a couple things to double check!
This could be vaccume issues and possibly timing also..
Is it a mechanical or electric fuel pump?

Is the distributor a HEI? if so 8 is not far enough advanced for aftermarket dist.. go to 12..and make sure you time it with the vac advance plugged off..I have had a similar issue with a 304 after HEI install?

While its idoling take a can of brake clean and squirt it around the base of the carb and the manifold. if it raises the idle you have a vac leak!!

And I wouldn't drop the tank just yet.. take the fuel line off at the engine and blow air backwords into the tank. have someone at the tank listen to the sound.. then hook it back up and see if it takes a while to have the same problem. may be something that was drooped in the tank or may not be?

 

[BubbaBull]

New fuel pump (mechanical) and filter installed just prior to new carb... new distributor cap and rotor.(old one did have a slight crack)
I did take my air compressor and blow back into the tank.. no change in performance afterward!
I do have a 1 gal gas tank off an old riding mower I'm thinking about rigging up as a temporary bypass just to isolate the gas tank and fuel lines.
I have wondered about the vaccum advance as the possible culprit since it appears that most all of the original hoses are gone... I am researching online what the connectivity is supposed to look like.
The timing was set to around 16 btdc when we checked the other day we changed it to 8 degrees but it did not make any difference.
Tomorrow we check for vac leaks... and possible fuel tank bypass.

 

[superj]

maybe the vent line is clogged and you are creating a vacuum in the tank that is not letting fuel be pumped? try driving with the gas cap off one time, that would eliminate that as one possible problem

 

[tjlboise]

maybe the vent line is clogged and you are creating a vacuum in the tank that is not letting fuel be pumped? try driving with the gas cap off one time, that would eliminate that as one possible problem

That's a good idea.