Cold weather Idle problem - Off-Road Forums & Discussion Groups
Jeep-Short Wheelbase All discussion of short wheelbase Jeeps: CJ, TJ, YJ and JK

LinkBack Thread Tools Display Modes
post #1 of (permalink) Old 12-18-2002, 11:54 AM
Posts: n/a
Cold weather Idle problem

I'm having problems with my jeep idle. When I first start it up it idles with the choke fine. When I rev it up and the choke comes off it idles a little low at about 650rpm. Once the needle on the temp guage starts to move is when the problem starts. It will idle at about 400rpm or it will stall. This continues to happen until the jeep is completely warmed up. It did it with the factory carb and the computer hooked up, factory carb and nuttered, and with the weber set up. It is driving me crazy. Any ideas?
Sponsored Links
post #2 of (permalink) Old 12-18-2002, 01:27 PM
Posts: n/a
Re: Cold weather Idle problem

If it makes you feel any better, my 84 CJ7 with a Weber 32/36 on the 258 does the exact same thing - the only thing I could narrow it down to is the thermostat/cooling system. As the thermostat begins to open, the coolant starts flowing (from an almost stagnant state) and the water pump which was previously just thrashing coolant in its housing is now actually pumping coolant through a partially?? open thermostat - which requires more energy from the crankshaft until the water flow is consistent through the whole system and up to temperature for the thermostat to be fully open.
Or I could be off my rocker [img]images/graemlins/grin.gif[/img]
Seriously though, it also could be something in the EGR valve/vacuum system, several of the emissions controls open at specific coolant temperatures.
Again... I could be way way off here.

post #3 of (permalink) Old 12-18-2002, 06:06 PM
Posts: n/a
Re: Cold weather Idle problem

First I would check all of your vac lines, make sure they're not cracked and are all attached and properly routed. A vac leak could cause a poor/rough idle.

Make sure your fuel filter is clean and the gas line to the carb is in good condition. Make sure your fuel pressure regulator is set with-in required limits (2 - 3.5 psi), and that the line doesn't run downhill toward the carb.
Then I would go to the timing. Let the engine come to full operating temp (when it's idling at 400 now), turn on all of your accessories ie lights, stereo, fan on high, then set the timing to 8 BTDC. Yeah, you might need some help keeping it running for this part [img]images/graemlins/smirk.gif[/img].

Then follow these instructions
Redline Weber

to reset the idle screw and idle jet to baseline settings and tune for lean-best idle.

Then, re-adjust the idle speed screw if needed, and your problem should be fixed. Good luck - Michael

Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Off-Road Forums & Discussion Groups forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome