4.0 auto erratic idle and flaky speedometer - JeepForum.com
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Unread 03-22-2013, 07:51 PM   #1
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1995 ZJ 
Join Date: Mar 2013
Location: Charlotte, NC
Posts: 13
4.0 auto erratic idle and flaky speedometer

Hey everyone,

I just lucked into the purchase of a 1995 Grand Cherokee Laredo with about 120,000 miles on the clock for $1,000 . It is a 4.0 auto with the 249 transfer case. I knew going in that it needed a new VC for the transfer case and have made peace with that aspect. The other reason it was so cheap was the fact it was having a shift issue at 45 mph.
After getting a chance to really get it out on the road and up to speed, it shifts fine through all gears but will randomly jerk above 45 mph. I have also noticed that when I lift off the gas, the rpms will bounce around as it coasts. I had the truck shut off when I put it in park a few times, but it restarted both times. The speedometer is also randomly working or not working as well.
With these symptoms, any ideas what I should change first? I know that the TPS, speed sensor, and crankshaft sensor could all be culprits according to the forums, but I would like to know what some of you guys and gals might suggest.

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Unread 03-23-2013, 04:06 AM   #2
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1994 ZJ 
Join Date: Aug 2011
Posts: 2,666
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