1978 Jeep CJ7 RUNS ERATIC NOT RELIABLE

TED NON MECHANIC

MEMBER
1978 JEEP CJ7

Engine Performance problem
1978 Jeep CJ7 6 cyl Four Wheel Drive Automatic? Miles

I did a compresion test to see what was wrong first I ran the motor till it warmed up then removed spark plugs starting from the ront of the jeep furthest away from the driver with the gas pedall to the floor turned it over for about ten seconds each cylinder and this is what I got 170 175 190 177 182 170 it will run good then just cut out or it will run then it will be just like the ide went real low at times then when driving it will die when stopping I tried to adjust the carb and get minimal results tried the timming, same thing I have playing with ths for what seems like years could it be he carb the plugs always look black like they are burning rich I looked for any vacum leaks and did not seem to find any also remember that this is not the firing order but from the front of the jeep towards the driver could the two cyl. That read 190 and 182 be clogged with carbon? Or is the carb bad and dumping to much gas into them or is this normal and just need a new carb? Please any advice is good thanks much TED

1 Reply

AIRSOFTSOLDRECN9

MEMBER
348 POSTS

Wow, that is way too high compression. You must have detonation, basically you just made a diesel engine (120-130 psi is normal). Far too much carbon buildup in the cylinders. You are running way too rich. You can try seafoam to get some of that carbon buildup out but I am not sure if that will fix everything. Unfortunatly that might take the carbon off areas you may not want to. You might have to take off the heads and clean up the pistons. If you have a catalytic converter then take it off wen you do this. It will belch out black smoke for maybe 15-45 seconds, depending on how bad everything is on the valve seats and the intake manifold too.