Need help with 151

jveesart

New member
City
Shallowater
State
TX
#1
I have an 81 CJ8 with the 151 and an SR4. I've only had it about a year and haven't messed with it much. It starts and idles fine but when I drive it after about 20 minutes it will die on me. It acts like its flooded. After about 45 minutes to an hour it will start up again just fine. Another 20 minutes or so same thing. I changed the plugs, plug wires, distributor cap, coil, and ICM. I checked all the vacuum lines and everything looks good. What am I missing? Thanks for the help
 

ag4ever

Average Nut
LIFETIME
CJ-8.com Member
City
Richmond
State
TX
#2
Sounds like your float may be sticking or the fuel pump is not pressure regulated (fuel filter) causing it to over power the needle and seat?

Or, you have a coil that is overheating and when it cools down it starts working again. Did you replace the coil or just see that you have spark?

It will be hard to diagnose it without knowing more symptoms.

If it is just flooded, you should be able to start it with a wide open throttle. To me it sounds more like a heat soaked ignition problem.
 

HighSierra CJ

Scrambler Enthusiast
LIFETIME
CJ-8.com Member
City
Ducor
State
Ca
#4
Check the fuel filter inside of the carb, where the fuel line screws in. It probably needs changed anyway. Most don’t realize there is one in there.
 

HighSierra CJ

Scrambler Enthusiast
LIFETIME
CJ-8.com Member
City
Ducor
State
Ca
#6
I had a scrambler with a 151, in the late 80’s. That little filter was the source of my carb problems and it took a while before I found it. Hope it helps.
 

jveesart

New member
City
Shallowater
State
TX
#7
Ok guys here’s where I am. I changed the little filter inside the carb, new plug wires, spark plugs, rebuild HEI distributor ( cap, rotor, and coil) and fuel filter. I’m starting to agree with ag4ever and think it’s electrical. I’m not sure what other information to give but after driving for about 20 minutes it just dies. It doesn’t sputter and try to run it stops immediately. It acts flooded but that could be because I’m going 40-50 with my foot on the gas when it dies. If I floor it and try to start it then it acts like it wants to start and sometimes does, sometimes it takes 10-20 minutes then fires right back up. It’s an 81 so not computer controlled. I have a single outlet fuel filter but according to chilton the 4 cylinder didn’t have a return line. Vapor locking? Any ideas?
 
Top