cruiser54

You're adjusting/replacing the electrical portion of the switch. Not near the key. Click on my tech photos link below and scroll through. You'll see it.

Yessir. And if that caps turns out to not hold pressure, replace it with a Napa 703-1396.

Be aware that the line between the master and slave should be replaced. There was an issue with them from 84 through 86 where the rubber of the line reacting adversely with DOT brake fluid and forms crystals from the disintegrating lining of the hose. Those abrasive pieces work their way into both cylinders over time.

Intermittent issues are a bear. Let's regroup and list what you have done so far.

only one O2.

Easiest to lower the column. Connector may not be too far gone.

Oz: Try removing the pivot bolt and spinning the booster rod 180* from where it is now.

Yup. Page 3 has the burned connector photo. Let's take wagers on what the issue is. Is gambling allowed on this site?

Begin by cleaning the ground strap connection at the firewall. Remove the bolt, scrape the firewall to bare metal, polish up the terminal, and reattach.

Easy enough to test the CPS when it's hot. Takes about 30 seconds.

Make sure the fuse isn't blown.... Also, don't tighten the attaching/pivot bolt down tight or the switch won't move. That's why there's a jamb nut.

The big brown wire on the ignition switch, located down the column from the key switch is fried at the switch. Switch is now bad. Replace switch, clean up that brown connector and wire as needed. Click on my Tech Tips link below and look on pages 1 and 3 to see what I'm referring to.

Are the bell housing to engine bolts loose? CPS wire getting pinched as the engine rocks?

I'm the guy who can't figure out how to post photos on Comanche Club. LOL.

There's some photos of it in my Tech Photos link below. Is there a ground strap from the back of the head to the firewall? If so, remove the end from the firewall, clean the connector, scrape the paint off the firewall, and reattach. The CPS can be TESTED. Post 7 in my Tips link below.

Apple cider vinegar and water 60/40 mix in a spray bottle.

Post 7.

Microsoft Security Essentials works great. Norton is like a bouncer at the door of a bar, slowing everyone down. MSconfig from the menu. Go to Start Up. Whittle it down to a minimum.

I would do the Bosch.

It's hard to assess your mechanical prowess from here. It's not difficult for a seasoned mechanic. I would modify the sensor before installing it per my tips, and provide the mechanic with a photo of the original wire harness routing as you can find in my Technical Photo link below.

If you don't know about this, check it out. Lots of photos. http://comancheclub.com/topic/43691-jeep-technical-photos/

Yup. PM me your email address. But then somebody's gotta post it in this thread!! LOL.

Someday I really need to learn how to post pics on this site.

I have a vacuum diagram for ya. PM me with your email address. With the engine at idle, spray along where the intake manifold meets the head with throttle body cleaner. The vacuum leak will show up. Just move the vacuum ball from the bumper to the passenger side rear corner of the engine bay and eliminate all the excess tubing.

I'm betting!! 5/16" square plug. An allen bit can be ground down a bit to work.