metering pins - picture please? - 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 11-14-2002, 02:13 AM Thread Starter
 
Join Date: Oct 2002
Posts: 713
Thanks: 0
Thanked 0 Times in 0 Posts
 
metering pins - picture please?

Does anyone out there on the board have a pic of the metering pins in there correct position that they'd be so kind as to post? I've located several articles that refer to setting the idle mix and needing the pin to be more or less centered, some of these articles refer to a pic that is on that page but the pic never loads. Even a very detailed description would be a help. Right now i'm running lean, with the pins pulled back into the stepper motor.

thanks,
pablo
YJOwnr22 is offline  
Sponsored Links
Advertisement
 
post #2 of (permalink) Old 11-14-2002, 06:48 AM
Bduece
Guest
 
Posts: n/a
Re: metering pins - picture please?

I don't have a picture but I can help. Get someone to sit in the drivers seat as you look into the carb. The metering pins will be towards the back of the throat of the carb. There are 2 pins but you will only see 1. They are on top of each other and the bottom one is about a 1/2 deeper in the carb. When you turn the ignition on just before the vehicle starts the metering pin will move from the front of the carb, then to the rear and then it will settle in the middle, or vise versa. Its the ecu testing the stepper motor. It moves fast and you could miss it. But try until you see it. Now with the pins set to the middle its a good time to unplug the stepper motor connection and the metering pins will stay there. If the pins set to the middle don't work well, you can take the stepper motor off the carb and move the pins with your hand by pulling or pushing the pins in and out of the stepper motor. My jeep ran the best with them all the way to the rear.

P.S. If you don't see the pin move try starting the vehicle. I can't remember if they move with the ignition key on or when the vehicle is first started. Either way once they settle in the middle you will have time to unplug the connector as long as this is done with vehicle cold.
post #3 of (permalink) Old 11-14-2002, 08:30 AM
**DONOTDELETE**
Guest
 
Posts: n/a
Re: metering pins - picture please?

Go here, lots of good info. Let me know if this has helped or not.
http://www.off-road.com/jeep/tech/258bbd/idle.htm
Sponsored Links
Advertisement
 
post #4 of (permalink) Old 11-17-2002, 08:00 AM
MaineJeep
Guest
 
Posts: n/a
Re: metering pins - picture please?

If I remember correctly, the Nutter instructions said to get the carb to full rich, pins all the way forward. Are you finding that things work better with your pins centered?
post #5 of (permalink) Old 11-17-2002, 08:37 AM
BigJ
Guest
 
Posts: n/a
Re: metering pins - picture please?

I have a photo but I think it is too big to post. I can email it to you if you want. The pins (at least the top one) is pretty easy to see. Remember the pins won't move until the engine is at operating temp. My pins don't really move at all as they stay towards the back (firewall). In this position the fuel mixture is rich and the computer is trying to lean it out by moving the pins to the rear. If I set the carb up so the pins move back and forth the engine runs really rough. Apparently that is a common problem with this carb/engine. It will pass emissions testing but it runs like crap. I turn the set screws on the carb out to make it run smooth although a little rich for the computers taste. I have been trying to get my rig to pass emissions here in MD and it has been quite a learning expierience. It passed yesterday so I think I understand most of the emissions/fuel intake/choke system. Let me know if you need anything else...
post #6 of (permalink) Old 11-17-2002, 10:12 AM Thread Starter
 
Join Date: Oct 2002
Posts: 713
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: metering pins - picture please?

Yeah that is literally exactly my problem, to a tee. I've gotta have the mixture screws turned out about 6 or 7 turns out to get any kind of decent idle, and even then it runs rough. I used to have a bunch of vacuum leaks, and I assumed that that was the problem, and I also thought perhaps the carb itself was at fault. I fixed evey vacuum leak and replaced the carb, still to no avail (although it runs a tad better now.) But my mileage still sucks. I'm going to do a TBI or perhaps just go with a WEBER as soon as I get the cash, and as soon as I pass emissions in 2 weeks.

pablo
YJOwnr22 is offline  
post #7 of (permalink) Old 11-17-2002, 06:27 PM
BigJ
Guest
 
Posts: n/a
Re: metering pins - picture please?

6 or 7 turns sounds a bit much. Check or replace the O2 sensor. You may want to check the carb. If it's re-built it doesn't mean that is in top shape. I had to take one back. There was a lot of applicable information in the 258 Primer (engine) on the main site. When I looked into the carb on the old one and the the first rebuilt one, I could see fuel dripping. The venturis were bad. Check the timing. Make sure the engine is hot when doing anything to tune it up. It takes a while to heat up the manifold. If you go to get it tested for emissions make sure it is running rough and lean. If you have problems with emissions remember that most of the emissions equipment is used during start up and after it is running the system pretty much shuts down. Except for the PCV system. If you are running rich there will be more hydrocarbons in the valve cover that will get fed back into a already rich system.

If it is a intermittent rough idle is is probably timing or the fuel mixture. If it is very accurate and timed it is usually mechanincal.

Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

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

Password:


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

Email Address:
OR

Log-in










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