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poor acceleration in 3rd

poor acceleration in 3rd

79cj5

Jeeper
Posts
4
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0
Location
clearfield,pa
I have a 79 CJ5 AMC 304 v8 3 speed and when i shift into 3rd gear and give it gas, It feels like something is holding it back and slowly releases and speeds up.Could it be the cat. converter is restricting it? New carb kit,fuel pump,wires,plugs and rotor/distributor.The cat.converter is also new.
 
Did you install all of this? or a shop?
with all that new you could have a multitude of problems on the tuning end.
ok, what is the manifold vacumn? and what is the recomended vacumn for the engine, is that a stock carb or a upgrade? Who set the float on the carb? whi set the preasure from the fuel pump. or does the carb have a preasure range it need to receive and or be restricted to? Who set the distributer? are they sure the thing is in perfect alignment with the crank? could it be off a gear or 2? have you set the dewell properly? All wires in proper place? Last thing I would worry abouut is a new Cat till all the other things are checked.
One more thing, the linkage to the accelerator pump, see if that is working good as a first step.
 
^^Baja has a lot of good points there^^

If the cat is new that shouldn't be the problem.
a 3 speed has a wide range between gears are you use to this, or have you had the jeep for a while and it just now started acting like this?
 
I know it may be a mute point now, but do one thing at a time
carb kit, tune it in. it coould be several things there, distributor, tune it in
etc etc etc, trying to find the problem with a bunch of new stuff can be hard, so take the list and do one at a time, till you get to the end and if you find several things were wrong you will have to go through the list again as each thing can effect the other.
Just trying to help

check accelerator pump linkage
check for a good seal with the manifold to carb gasket
check fuel pressure and see if it is in range
check the manifold vacuum
check firing order
check dewell
if you still have a problem check the set of the distributor
if the carb is aftermarket, you may need to take it to a carb specialist, that means an old mechanic, and have it checked for jet sizing and all.
most younger guys do not have the experience to work on carbs
 
Check Vaccum advance, it may need some love. Also dont just check the vac advance, check the tube that runs out of it as it may be plugged. That tends to happen from time to time.

also you may want to check spark plug gap, and be sure the points are set properly
 
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