99 Sport, 4x4 auto, 4.0 really likes Overdrive...

jhc7399 · Apr 10, 2015

Installed a rebuilt engine 2-3 months ago. I don't think that has anything to do with it. I have also adjusted the kd cable a few times to remedy the problem and nothing changes.

I can be driving between lights and as soon as I get to around 42-43 mph it shifts into OD? If I push it hard in 2nd it will go to around 3000 rpms go from 2nd to 3rd and then go straight to OD only using 3rd 5-10 seconds. When I am driving along in the 40 mph range in OD seems like it takes it forever to go down to 3rd. Seems like it loves OD and doesn't want nothing to do with 3rd.

Thanks!

iluv83vettes · Apr 10, 2015

The computer tries to keep it in OD at 40+ MPH. If I am cruising around town 40-50 I keep it in 3rd.

notamos · Apr 10, 2015

iluv83vettes said:
The computer tries to keep it in OD at 40+ MPH. If I am cruising around town 40-50 I keep it in 3rd.

Ditto.

jhc7399 · Apr 10, 2015

So this is normal, no problems?

iluv83vettes · Apr 10, 2015

Correct. It is worse if you have bigger tires, stock gears, and a stock speedo gear. It's talked about a bit in TonySS's build thread.

techno1154 · Apr 11, 2015

iluv83vettes said:
The computer tries to keep it in OD at 40+ MPH. If I am cruising around town 40-50 I keep it in 3rd.

I keep mine in 3 up to 45MPH,....longer if I think I would have the need to speed up quickly. I find it annoying to say the least.

Jesse_Hallum · Apr 12, 2015

If anyone reading would enjoy better shifting, try this:

1. Adjust the transmission cable, at the TB for normal shifting, or by pressing the accelerator to the floor for sport shifting.

2. Reset the computer. I prefer pulling both battery cables and touching together for 30 seconds, reattach cables, key on no crank, headlights on then off, then key off.

3. Key back on, no cranking, press throttle slowly to the floor, and back. Key off.

Step 3 gives the computer more information about the max TPS voltage. I stumbled across this a while back, while watching scanner numbers after a reset. Including step 3 in a reset procedure makes it shift silky-smooth, and prevents over/undershirt points, esp. when flooring the throttle. Give it 5 mins. of normal driving to relearn other things, then you will see the difference this makes. This works like a charm on my 2001 Sport.

techno1154 · Apr 13, 2015

The earlier XJ's have an independent TCM i:e it is not a part of the ECM. I am not sure the same reset procedure will work.

jhc7399 · Apr 13, 2015

Jesse_Hallum said:
If anyone reading would enjoy better shifting, try this:

1. Adjust the transmission cable, at the TB for normal shifting, or by pressing the accelerator to the floor for sport shifting.

2. Reset the computer. I prefer pulling both battery cables and touching together for 30 seconds, reattach cables, key on no crank, headlights on then off, then key off.

3. Key back on, no cranking, press throttle slowly to the floor, and back. Key off.

Step 3 gives the computer more information about the max TPS voltage. I stumbled across this a while back, while watching scanner numbers after a reset. Including step 3 in a reset procedure makes it shift silky-smooth, and prevents over/undershirt points, esp. when flooring the throttle. Give it 5 mins. of normal driving to relearn other things, then you will see the difference this makes. This works like a charm on my 2001 Sport.

Never heard of doing it that way, I will give this a try and get back here, thank you.

sidewaysstarion · Apr 13, 2015

Jesse_Hallum said:
If anyone reading would enjoy better shifting, try this:

1. Adjust the transmission cable, at the TB for normal shifting, or by pressing the accelerator to the floor for sport shifting. I'm not sure what you mean by this:huh:

2. Reset the computer. I prefer pulling both battery cables and touching together for 30 seconds, reattach cables, key on no crank, headlights on then off, then key off. The headlights don't interface with the pcm at all on our jeep, so how does that work?

3. Key back on, no cranking, press throttle slowly to the floor, and back. Key off. The ecu learns the tps limit voltages while the engine is running, doing a throttle sweep with the engine on or off has the same effect

Step 3 gives the computer more information about the max TPS voltage. I stumbled across this a while back, while watching scanner numbers after a reset. Including step 3 in a reset procedure makes it shift silky-smooth, and prevents over/undershirt points, esp. when flooring the throttle. Give it 5 mins. of normal driving to relearn other things, then you will see the difference this makes. This works like a charm on my 2001 Sport.The PCM has nothing to do with transmission shifting, only running the engine, the TCM in your jeep is what controls the transmission

As for the OP, what you describe sounds normal. the reason it stays in OD so long is to help with fuel economy.

jhc7399 · Apr 13, 2015

I was thinking that if it was supposed to be like that is was and economy thing.

99 Sport, 4x4 auto, 4.0 really likes Overdrive...

jhc7399

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iluv83vettes

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notamos

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Jesse_Hallum

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