ameridacusa@yahoo.com

Hi.! I'm 17y/o, and love my new 4.0 GC.! The problem is that it feels like it is shutting off ( skips at times ) especially at 50-60mph.! It feels like you turn key off/on rapidly.! This causes the universal joint in rear on 2WD to bang.! Kinda scary when every thing is tight under the Jeep I.e, new shocks, new bushings, universal joints etc.! At low idle the engine will skip at times but never cut out completely.! Any help guys? I like mechanical problems, and not into girly things.!

1ATony

If you haven't changed the plugs, wires, rotor and cap in a long time, I would start there first if it feels like it's bucking or skipping on you.

ameridacusa@yahoo.com

Thanks Tony.! Changed all the parts you requested.! Still misfires at all speeds, now and then, sometimes it's good for hours of driving but skips at idle also.
Just noticed that it's having a hard time going into overdrive. Could this be related? At 49 mph it always shifted to OD.! Now it's takes forever, sometimes it never gets into OD.! At 50mph I should be at 1500-1600 rpm.! Not so today.!
Can the OD kick in speed be adjusted? Thanks for your ad for parts will contact you from now on.!

kcjeeper126

If you havent already, try changing the TPS (throttle position sensor) on the throttle body. I have changed mine twice in my wj with a 4.0. Both times I was having problems similar to what you describe. Hope this helps, Rob.

ameridacusa@yahoo.com

Thanks so much Rob.! I'll take your advice with the TPS.! one quick question! When does your OD kick in? At what speed? And can you make it kick in at any speed you select? My Dad had a Austin Healey 100s years back with an electric switch on the dash that let it shift when he wanted.! Maybe a silly girl thinking out of the box on this.!
Again, Thx ever so for replying to my problem!

Bustedknuckle

Nah, it's not going to let you kick in overdrive. On ZJ Grand Cherokees, overdrive was around 50 mph if I recall. (At least that's when my 96 Grand Cherokee usually does).

So far so good on the advice. The TPS was also a good suggestion. Depending on how many shots you want to take at it, I'd also recommend replacing the MAP/BAP sensor, located next to the TPS sensor, near the throttle body. If that gets choked up with deposits and grime overtime, it can produce a false reading.

My question, is the Check Engine Light on?

ameridacusa@yahoo.com

Yep.,! Check lite on.! Now OD won't kick in at all .!

Bustedknuckle

Swing by any auto-parts store or repair shop and ask if they do a free check engine light scan. You don't want it erased, just want to know what code it's setting. PXXXX will be what we're interested in. It may not resolve the issue, but it's a hint to point you in the right direction.

Being a 97 you can also pull a generic Chrysler specific code via the odometer. Do a simple search here on CherokeeForum to see how to get codes out of the odometer. Those however are a little bit more vague, but also a decent starting point.

94zjdriver

OD should kick in at about 45. depending on how hard you are pushing it. LOL
if the throttle position sensor doesn't do it. Look inside the dist and make sure the screws are tight, don't strip them. can cause a bouncing and intermitten miss if not tight. Might also try wiggling the wires at the computer to see if you can get the problem to get better or worst. Thoes connectors have a bad habbit of having lose wires.. If you can get the problem to get better or worst wiggling the connectors then take them off and clean them inside and push the wires in to get a good connection.. Also make sure you have a good ground from the body to frame and engine to frame. the computer is very sensitive to ground issues. When you take the connectors off you will see some usually black/brown grease there that has harden over time and needs to be taken out and replaced.. Needs to be there to keep the contacts from corroding or turning green. we had a simurlar problem with a cj and his was a burnt ground wire that had somehow gotten lose and was not touching but very close to the exhaust and had melted the insulation in one spot and when going down the road the wire would bounce off the frame shorting and causing the engine to "shut off" for a split second, intermittely. Drove us nuts trying to fine that one...