help. shake at low rpm 45mph -
LinkBack Thread Tools
post #1 of 3 Old 12-27-2014, 01:15 PM Thread Starter
Registered User
1990 MJ Comanche 
Join Date: Dec 2014
Location: tumtum
Posts: 1
help. shake at low rpm 45mph

I have a 1990 jeep comanche 4.0l i6. 4 speed auto . I had a buddy put in a new engine for me. With the engine he did new injectors and intake manifold. When I got it back it ran a little rough. My main concern is that when I'm driving and it shifts from 3rd to 4th and drops rpms to about 1250-1500 it starts shaking in the steering wheel. It seems like right around 45 mph is when it's at its worse... when I hit about 55pmh I can no longer feel it. If i incease the throttle and it downshifts or if it increases rpms in 4th the shaking stops. I have noticed that it seems to happen more frequently in comfort mode on the tranny switch.. but this may be because it runs at lower rpms typically in comfort mode.

Since I got it back I have replaced the egr, tps,maps, exhaust manifold. O2 senser. I'm sure the vaccuum lines are all on correct... it idles a little rough at about 700-800. I'm at a loss at what could be causing it.. I've replaced everything I thought it could be... now I'm starting to think it may be something with the tranny.

slimslover is offline  
Sponsored Links
post #2 of 3 Old 12-27-2014, 06:48 PM
Registered User
Motorcharge's Avatar
1999 WJ 
Join Date: Oct 2008
Posts: 13,775
My 91 is doing the same thing. Haven't had time to check it out yet, but it's driving me nuts. Hope someone has a solution. I was thinking TPS myself.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
| June 2015 COTM |

Originally Posted by Ron Swanson
There is no such thing as bad weather. Only inadequate clothing and transportation.
Motorcharge is offline  
post #3 of 3 Old 12-27-2014, 08:49 PM
Registered User
87MJTim's Avatar
1987 MJ Comanche 
Join Date: Dec 2012
Location: New Market, MD
Posts: 560
If you can ride out of the wooble, I would say tire balancing.

Have a shop check you alignment, especially the ball joints. Ask me how I know.



87 Comanche, 4.0, AX15 (formerly BA10/5), D44
84 CJ7, 4.0 (93 XJ) AX15 (Formerly T5)
87MJTim is offline  

1990 , comanche , shake , vibration

Quick Reply

Register Now

In order to be able to post messages on the 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 e-mail address for yourself.

Email Address:


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Posting Rules  
You may post new threads
You may 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 Off
Pingbacks are On
Refbacks are On

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