need some help. jeep doesn't want to drive past 25 mph

need some help. jeep doesn't want to drive past 25 mph

yetiwarrior82

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Vehicle(s)
Stock 1979 CJ7
258 4.2L Inline 6
Auto tranny with quadratrac
ok i have a 79 CJ7 with an 83 258 in it. i rebuilt my carb a few days ago and now i tried to drive it down the road and i reached 25 mph and no higher then that and then it sounds like its going to die on me. what did i do wrong? someone help me out please.
 
Picture of the carb please < 2 or 3 pics no air filter >, possibly model.

Just a bit more information my friend and many here will do their best to assist you.
 
Picture of the carb please < 2 or 3 pics no air filter >, possibly model.

Just a bit more information my friend and many here will do their best to assist you.

i'll take pics when i can. its a stock carb. the air filter is also stock as well.
 
The '83 258 has a computer controlled ignition advance in it, whereas the '79 does not. This means that the '83 distributor will not advance as far as the '79 will. An option would be to get a remanufactured unit like from Crown or use the one from the '79. I'm sure this is not your only issue, but could be part of it.
 
Answering some of these might help, especially if it's the carter.


How does it start and idle? Does it start sputtering at 25 or what exactly is it doing? Did you set your float and metering pins etc or just break down and put new gaskets in? Did you soak and clean the carb and clean all the little ports out?
 
Answering some of these might help, especially if it's the carter.


How does it start and idle? Does it start sputtering at 25 or what exactly is it doing? Did you set your float and metering pins etc or just break down and put new gaskets in? Did you soak and clean the carb and clean all the little ports out?

sorry ive been at work. but anywho, it starts and idles fine. drives fine until you reach 25. then it doesn't really sputter but it just sounds like it is going to die. i did adjust everything according to charts in the manual. i cleaned everything. it worked fine until i rebuilt the carb. so i don't know if i messed something up or not.
 
sorry ive been at work. but anywho, it starts and idles fine. drives fine until you reach 25. then it doesn't really sputter but it just sounds like it is going to die. i did adjust everything according to charts in the manual. i cleaned everything. it worked fine until i rebuilt the carb. so i don't know if i messed something up or not.
I would recheck/adjusted your accelerator pump linkage, metering rods, and float adjustment. I would also check to see if the new rebuild kit came with one or two washers for the needle and float, where your fuel line attaches to the carb. When I rebuilt mine the kit only came with one washer and when I rebuilt it threw off the float adjustment. I when back to the old two washers and readjusted the float and everything was fine and dandy. Also did you check your mixture screw adjustment before your rebuilt it. How many turns in/out they where before you took them out to clean the carb? :)
 
I would recheck/adjusted your accelerator pump linkage, metering rods, and float adjustment. I would also check to see if the new rebuild kit came with one or two washers for the needle and float, where your fuel line attaches to the carb. When I rebuilt mine the kit only came with one washer and when I rebuilt it threw off the float adjustment. I when back to the old two washers and readjusted the float and everything was fine and dandy. Also did you check your mixture screw adjustment before your rebuilt it. How many turns in/out they where before you took them out to clean the carb? :)

i can't remember what they were at but i put them back right. i know i did. if i got a new carb would that fix this problem?
 
i can't remember what they were at but i put them back right. i know i did. if i got a new carb would that fix this problem?
Not to sound condescending, but if you don't remember what they were at how do you know if you have them adjusted right. If you don't want to recheck the accelerator pump, float, and metering rods, if the metering rods are not in the jets properly it will not open up correctly. I would at least check the mixture screws buy turning them all the way in, and backing them out two complete turns this should give you a good starting point. Do not over tighten the screws just tighten till you feel the slights resistance, cause this can cause damage to the needle and seats. :)
 
Accelerate past your normal RPM shifting range in first gear. If you accelerate without any issues to a high RPM it isnt the mixture screws. If it was, the jeep would start sputtering when you were at a certain RPM and not a speed.
 

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