Jump to content

nOOb with some questions


Gabbo
 Share

Recommended Posts

Hello all,

I bought a '90 MJ last year and have been having a blast with it.  Once I work out how to post pics I will do just that.  Here's some specs:  1990 4.0, 5 speed, 4x4.  It has an open air filter, header, high-flow exhuast, 6 inch Terraflex lift, Summit Racing 15" steelies, BFG 33x10.50 AT's, and it's fair share of character.  I actually converted to the dark side when I sold my '81 Land Cruiser and picked up this MJ.

The truck developed a high-idle problem somewhere along the line that I am still chasing.  I've done a tune up and replaced the IAC.  Removing and cleaning the throttle body and checking the manifolds for leaks and loose bolts is my next step.  I messed with the TPS before I stumbled upon this website and found some knowledge saying "DON'T MESS WITH THE TPS" so I'll have to follow the steps to get it back in line.  

There is one thing I still can't figure out.  I've been working on it for a month now and I just turn up nothing.  I need a tie rod end for where the drag link meets the pitman arm.  It is a dropped pitman arm and it is factory steering.  "Get a steering upgrade!" is unfortunately an answer that doesn't work for me at this time because funds are tight.  When I got the part from NAPA it is too short.  As in only a 1/4" of threads would go into the adjusting sleeve.  Is there another, longer, tie rod end that will work?  Some where I saw someone say a 91-2001 Grand Cherokee drag link to pitman arm tie rod end would work.  I haven't had the local parts store pull the two parts for comparison yet but am I barking up the wrong tree?  Or does that have some merit to it?

This truck is my daily driver and my goal is to be Rubicon ready by next Labor Day.  

Thanks!  And happy wheeling!

~Gabbo

Link to comment
Share on other sites

There can also be a mechanical problem resulting in high idle.

 

The cable from the accelerator peddle leads to a bellcrank lever that pivots on a bracket mounted on the driver's side frame ear, below the master cylinder. From there, a rod extends up to snap onto the ball stud on the throttle body. Every few years (usually after a tough winter) I've found on my '88s that the pivot point (joint) of the bellcrank gets either corroded or contaminated with enough gunk that it doesn't allow the throttle to close all the way when pressure is released from the peddle. Soaking the pivot with PB Blaster has resolved this.

Link to comment
Share on other sites

  • 2 weeks later...

Got my idle fixed thanks to the renix tips!  Well, I hope.  Read on:  I checked my throttle linkage and all was well.  I checked and re-checked for vacuum leaks and found none.  My manifold bolts were secure.  I re-did my grounds, unplugged many electrical connectors, cleaned them, and reattached them.  Still High idling.  I reset my butterfly valve stop postition position, and reset my TPS.  I noticed the fix came when I reset my butterfly valve stop position.  When I loosened the screw the valve dropped quite a bit before it stopped (and I reset it accordingly).  I understand this isn't an idle adjusting screw, but why would that fix my idle?  Did the problem start when it somehow work itself in thus opening my valve a little?  I'm confused.

I think I've tracked down my tie rod end problem too.  After loads of online research I had they guy at the local Napa pull the same part out for a 92 jeep Cherokee and turns out it was the correct part that I needed!  So my 90' MJ has a 92 Cherokee drag link assembly.  (Wrote that down in my owner's manual)

Next is tearing apart the steering column and fixing my high-beam switch.

Link to comment
Share on other sites

Got my idle fixed thanks to the renix tips!  Well, I hope.  Read on:  I checked my throttle linkage and all was well.  I checked and re-checked for vacuum leaks and found none.  My manifold bolts were secure.  I re-did my grounds, unplugged many electrical connectors, cleaned them, and reattached them.  Still High idling.  I reset my butterfly valve stop postition position, and reset my TPS.  I noticed the fix came when I reset my butterfly valve stop position.  When I loosened the screw the valve dropped quite a bit before it stopped (and I reset it accordingly).  I understand this isn't an idle adjusting screw, but why would that fix my idle?  Did the problem start when it somehow work itself in thus opening my valve a little?  I'm confused.

I think I've tracked down my tie rod end problem too.  After loads of online research I had they guy at the local Napa pull the same part out for a 92 jeep Cherokee and turns out it was the correct part that I needed!  So my 90' MJ has a 92 Cherokee drag link assembly.  (Wrote that down in my owner's manual)

Next is tearing apart the steering column and fixing my high-beam switch.

The IAC adjusts the amount of air necessary to maintain the proper idle speed. It gets out of it's parameters when the butterfly stop screw is mis-adjusted. 

Link to comment
Share on other sites

Just found a vacuum line that wasn't connected.  One of those real skinny ones that goes down to the EGR stuff.  There was a screw in the line, and the spot it went to on the little module on the fender was also plugged.  All the other lines were still hooked up.  I also disassembled the little plastic vacuum diaphragm thing just ahead of  the EGR and it's internals were damaged.  After I repair and replace stuff here should I go back and reset my TPS?  I'm hoping also this helps me pass emissions.  I'm failing O2 by .07%

Link to comment
Share on other sites

Scratch that guys, my EGR has been disabled.   The header has no line going from it to the EGR.  The EGR valve wasn't removed and blocked, it was just disabled.  The emissions testing place, on their paperwork, says "EGR PASS" and are testing it as if it's there.  My paperwork from last year says "EGR N/A" and appears to have very different criteria.  Does anybody have  a link to information about EGR DELETE so I can  remove the stuff rather than have it sit there and potentially cause problems?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...