82 Iron Duke - Low power, hesitation at low rpm

Rmhavema

Overlander
LIFETIME
CJ-8.com Member
City
Northville
State
MI
#1
Last year the iron duke was running great. I parked it for the winter and did a bunch of suspension/driveline updates. I have taken it for a few test drives recently and the iron duke seems to be running a little off. My issue is that at lower rpm, the engine seems to bog down and feels low on power, especially under load on hills. After I get over ~2500 rpm, the engine perks up and seems to run as expected. The engine starts up good, and idles smooth as expected. One thing I noticed is that the tachometer reads high and is erratic when the engine is hesitating (probably about 2x actual rpm). So, during acceleration, the tachometer climbs up to a false reading of ~4500rpm, then abruptly drops to 2500rpm (what I believe to be the actual engine rpm), and then the engine perks up and accelerates as normal. I am pretty sure the tachometer is working properly because I tested 2 different ones and got the same result. Timing or vacuum advance issue? Any help would be appreciated.
 

CJ7Pilot

18436572
LIFETIME
CJ-8.com Member
City
Yuba City
State
CA
#2
It sounds ignition related to me. A false high reading on your tach (and verified by a second tach) means too many pulses are coming down that wire.

Does your distributor have points in it? My first thought is to check the condition of the points and condenser.
 

Rmhavema

Overlander
LIFETIME
CJ-8.com Member
City
Northville
State
MI
#3
Thats what I am thinking too. I will take a closer look at the distributor, check timing, and test the vacuum lines for proper function. :shrug:
 
City
Halifax
State
UK
#4
Just a suggestion but its not the same gas from last year in the tank is it? I had issues trying to get mine to rev due to some old Gas in my tank, no issues starting or idling, put some new in and it sorted it.
 

Rmhavema

Overlander
LIFETIME
CJ-8.com Member
City
Northville
State
MI
#5
:bacon:I fixed it! Ended up being a bad aftermarket coil. I took it off and installed an old original coil from some parts I got from jeeperdd. It runs great now! :bacon:
 

IAFFCJ

Scrambler Junkie
LIFETIME
CJ-8.com Member
SOA Member
City
Manassas
State
VA
#9
Good deal. That Jeeperdd guy always got the right parts laying around.
 
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