I purchased a 99 jeep that has had a drive line change
5 speed to automatic swap. When driving the jeep at constant speed the up shift indicator will flash on and back off again. over and over each time it does the engine has a change in rpm of about 200 causing a slight lerge. any fixes for this

 

I can't help you fix the lerge?, but just do like I do with that stupid upshift indicator light and ignore it. With an automatic, it shouldn't even be enabled. It's only used with the manual tranny. If your Jeep went from a 5 speed to an auto, whoever did the work forgot to disconnect something.

ISince you have an auto this doesn't really matter to you, but that light's getting its info from your PCM, and that module is very confused. If you upshift based on that light you may get better fuel economy, but neither you nor your Jeep will be having any fun. Shift when it feel right not when an idiot light tells you to.

I don't even see that stupid light anymore. It used to be a major PITA, but it's totally tuned out now. If you can't tune it out, see if there's a dedicated fuse you can pull. I'd go check my owners manual to see if there is one, but it's outside in the Jeep and it's a little brisk out there for a guy in lounging around in lounge wear :)

Failing everything else, you could always take apart your instrument cluster and pull the bulb.

 

Below is what the FSM says (in part) about that lamp. But you shouldn't even have that indication lamp working with an automatic tranny. You need to track dowm and disable whatever is still functioning that's related to that light. It might solve your lerge :)

"Vehicles equipped with a manual transmission have an upshift indicator lamp. The upshift indicator lamp gives an indication when the driver should shift to the next highest gear for the best fuel economy. The lamp is controlled by the instrument cluster circuitry based upon a message received from the Powertrain Control Module (PCM) on the Chrysler Collision Detection (CCD) data bus. The upshift indi-
cator lamp illumination brightness is also adjustable, using the same input from the headlamp switch as the cluster illumination lamps.

The PCM uses inputs from many sensors and its internal programming to decide whether the engine speed and load conditions are correct for a transmission upshift. The PCM then sends the proper message to the instrument cluster on the CCD data bus to turn the lamp on or off. The PCM will send a lamp-off message three to five seconds after a lamp-on message, if an upshift is not performed. The
lamp will then remain off until the vehicle stops accelerating and is brought back into the range of lamp operation, or until the transmission is shifted into another gear."

Good luck and keep us posted.

 

Take a piece of electrical tape and put it over the light..voila.. no light..

 

That's just ugly

The point the OP needs to consider is that he's got an auto and that light shouldn't be enabled in the first place. It's only for a manual transmission.

The lurch he's getting is probably the tranny switching when the light tells it to :).

I read somewhere that Stu or JB, not sure who at this point, thought that even after a 5 sp to auto swap the little light was very well synchronized with the transmission's behavior.

I still recommend totally ignoring that stupid light and hitting the skinny pedal.

 

Remove the bulb, it's only purpose is to annoy!

 

I've seen this fix applied to vcrs with the flashing 12:00

Billy