Vacuum/carburetor help needed '81 2.5 Iron Duke

City
Terlingua
State
TX
#1
Hey y'all,
Trying to get my little 4 cylinder Iron Duke to run better and idle. I installed a rebuilt carburetor on it and it still won't idle 'cold'. 55 degrees here today.

One thing I'm not certain is that I either have all the vacuum lines, or if I do that they are connected in the right place. Is there a vacuum diagram anyone can share?

I'm a weekend mechanic (novice compared to y'all) so any advice appreciated.
 

FLCJ8

Legacy Registered User
City
Palm Bay
State
FL
#2
Hey y'all,
Trying to get my little 4 cylinder Iron Duke to run better and idle. I installed a rebuilt carburetor on it and it still won't idle 'cold'. 55 degrees here today.

One thing I'm not certain is that I either have all the vacuum lines, or if I do that they are connected in the right place. Is there a vacuum diagram anyone can share?

I'm a weekend mechanic (novice compared to y'all) so any advice appreciated.
There are diagrams here for AMC cars (starting at Fig. 45)
https://www.autozone.com/repairinfo/repairguide/repairGuideMain.jsp?pageId=0900c152800853e3
There are several based on trans, A/C, CA/Non CA, etc.
 
City
Terlingua
State
TX
#3
Thanks for the reply. I'm absolutely new to this so trying to understand. I was told that my 4 cyl is a GM engine nicknames the Iron Duke. When I go through those engines it seems those diagrams are for AMC 4 cyl and would not apply to the engine I have.

I'm going through a CJ manual I have but so far no luck finding the exact diagram I need for this motor.
 

FLCJ8

Legacy Registered User
City
Palm Bay
State
FL
#4
Thanks for the reply. I'm absolutely new to this so trying to understand. I was told that my 4 cyl is a GM engine nicknames the Iron Duke. When I go through those engines it seems those diagrams are for AMC 4 cyl and would not apply to the engine I have.

I'm going through a CJ manual I have but so far no luck finding the exact diagram I need for this motor.
AMC used the Pontiac 2.5L 151cid "Iron Duke" in their vehicles in 1981.
vacuum.JPG
I know some of the items may not be on your Jeep as the emission requirements were more stringent for passenger vehicles. I thought you would be able to at least confirm the correct location of your existing lines.
Here's a diagram for a '82 manual trans, 49 state that may help.
vacuum.JPG 1982.JPG
 
City
Terlingua
State
TX
#6
Thanks for everyone's help with this, I really appreciate it!

The weather cooperated and I was able to spend some time on the 8 today. With a 60 degree day it's now idling when cold and warm. Now on to blinkers so it will pass inspection and get new tires that are not dry rotted.

IMG_0758.JPG
 
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