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Weird shift points and high idle

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Old 01-15-2014, 04:03 PM
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Default Weird shift points and high idle

So I replaced the tps and the cps, still acts the same, all vacuum lines are good. It idles at 1200- 1500 and the tranny shifts weird like doesn't know what gear to be in on the highway. I checked the fluid it was darker than normal so I added some lucas to it. Any ideas or help PLEASE!!!!!!!!!!
Old 01-15-2014, 05:22 PM
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Ever adjusted detent/kickdown cable ?
Old 01-15-2014, 06:25 PM
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that and the throttle cable
Old 01-15-2014, 06:55 PM
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How to adjust the TV cable. Worth a shot....

https://www.cherokeeforum.com/f2/free-quick-fix-41821/
Old 01-15-2014, 07:43 PM
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no I haven't adjusted that cable yet. Ill try that tomorrow along with the throttle cable. Is there any adjustment when replacing the tps?
Old 01-15-2014, 07:53 PM
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Originally Posted by XJ_will
no I haven't adjusted that cable yet. Ill try that tomorrow along with the throttle cable. Is there any adjustment when replacing the tps?
No.
Old 01-15-2014, 08:12 PM
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How about the IAC?
Old 01-15-2014, 08:49 PM
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Sounds like you're long overdue for a transmission fluid change... it needed it BEFORE you put the red molasses in there.

I agree, adjust the TV cable. Unless you bought a Mopar TPS there's a reasonable chance you may have a dud. tjwalker has some excellent instructions on how to actually test the sensor... somewhere around here...
Old 01-16-2014, 08:04 AM
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I heard that if your fluid is darkish brown you dont want to change it because it will just finish off the tranny. I'm gonna change the filter today and check all that other nonsince. Its a duralast tps. The second one I got. The first one fell apart.
Old 01-16-2014, 09:28 AM
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Load of bull pucky from an old wives tale from a single transmission many many years ago... you keep ancient roasted fluid in a Japanese slushbox and they'll stop working guaranteed. Doing a power reverse flush can cause damage, but not a fluid change.

Yeah I don't have much confidence in Duralast sensors. I found this finally - give it a spin!

Originally Posted by tjwalker
The throttle position sensor is connected to the throttle shaft on the throttle body. It sends throttle valve angle information to the PCM. The PCM uses this information to determine how much fuel the engine needs. The TPS is really just a simple potentiometer with one end connected to 5 volts from the PCM and the other to ground. A third wire is connected to the PCM. As you move the accelerator pedal with your foot, the output of the TPS changes. At a closed throttle position, the output of the TPS is low, about a half a volt. As the throttle valve opens, the output increases so that, at wide open throttle, the output voltage should be above 3.9 volts. Testing can be performed with an electrical meter. Analog meter is best. You are looking for a smooth sweep of voltage throughout the entire throttle band. While slowly opening and closing the throttle, take note to the movement of the voltmeter needle. There should be a direct relationship between the needle motion to the motion of the throttle. If at anytime the needle moves abruptly or inconsistently with the movement of the throttle, the TPS is bad

You should have 5 volts going into the TPS. At idle, TPS output voltage must be greater than 200 millivolts. At wide open throttle (WOT), TPS output voltage must be less than 4.8 volts.. The best is to use an analog meter (not digital) to see if the transition from idle to WOT is smooth with no dead spots. With your meter set for volts, put the black probe on a good ground like your negative battery terminal. With the key on, engine not running, test with the red probe of your meter (install a paper clip into the back of the plug of the TPS) to see which wire has the 5 volts. One of the other wires should show .26V (or so). The other wire will be the ground and should show no voltage. Move the throttle and look for smooth meter response up to the 4.49 at WOT.

Perform the test procedure again and wiggle and/or tap on the TPS while you watch the meter. If you notice any flat spots or abrupt changes in the meter readings, replace the TPS.

The TPS is sensitive to heat, moisture and vibration leading to the failure of some units. The sensor is a sealed unit and cannot be repaired only replaced. A TPS may fail gradually leading to a number of symptoms which can include one or more of the following: -

NOTE: The throttle position sensor is also DIRECTLY involved with transmission shifting characteristics! It should be verified early in the troubleshooting process, when a transmission issue is suspected!

• Poor idle control: The TPS is used by the ECU to determine if the throttle is closed and the car should be using the Idle Air Control Valve exclusively for idle control. A fault TPS sensor can confuse the ECU causing the idle to be erratic or "hunting".
• High Idle Speed: The TPS may report faulty values causing the engine idle speed to be increased above normal. This is normally found in conjunction with a slow engine return to idle speed symptom.
• Slow engine return to idle: A failing TPS can report the minimum throttle position values incorrectly which can stop the engine entering idle mode when the throttle is closed. Normally when the throttle is closed the engine fuel injectors will be deactivated until a defined engine RPM speed is reached and the engine brought smoothly to idle speed. When failing a TPS will not report the throttle closed and fueling will continue causing the engine to return to idle very slowly.
• Engine Hesitation on Throttle Application: The TPS is also used by the ECU to determine if the driver has applied the throttle quicker than the Manifold Air Pressure sensor can read. The fueling is adjusted acordingly to cope with the sudden increase in air volume, however a faulty sensor can cause the ECU to ignore this data and the engine will "hesitate" when applying the throttle. In extreme cases with the engine at idle, a sudden application of full throttle can stall the engine.
• Engine Misfire: A fault TPS can report values outside the deined acceptable range causing the ECU to incorrectly fuel the engine. This is noticable as a slight misfire and can trigger the misfire detection software and/or Malfunction Indicator Lamp (MIL) light on the dashboard. Extreme cases can cause excessing misfires resulting in one or more cylinders being shut down to prevent engine and catalytic converter damage.
Old 01-16-2014, 12:56 PM
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Filter and refill from what drains out you should be fine. A complete drain flush and refill your asking for trouble....This however will have no effect on high idle and dought it going to change shift points. Adjust detent then see if manifold bolts are loose.
Old 01-16-2014, 04:42 PM
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Originally Posted by XJ_will
I heard that if your fluid is darkish brown you dont want to change it because it will just finish off the tranny. I'm gonna change the filter today and check all that other nonsince. Its a duralast tps. The second one I got. The first one fell apart.
Whoever told you that, don't ever take advice from them because they are absolutely full of ****.
Old 01-22-2014, 09:45 AM
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Ok well I changed the fluid added 50% Lucas changed the tps,cps adjusted kickdoen cable tightened manifold bolts, cleaned out tb did tune up. Its a bit better on shifting but still the same stuff. When I put my foot into it it just shifts up to lower rpms and when I back off it down shifts.
Garbage!!
Old 01-22-2014, 10:03 AM
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What on earth did you put Lucas **** in there for. The transmission runs on Dexron III/Mercon...
Old 01-22-2014, 10:05 AM
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because Lucas is good stuff. Can't hurt it.


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