They also canned the Disco (which lessens wear on components), and the AW-4 as well. I'm not convinced Chrysler saving money on production resulted in a better product for us. Granted that "comfort" switch reeks of a sales gimmick, but I'm pretty sure in general, going farther in a rev results in better MPG. (if you are not lugging) 1% gain in 300K at 16MPG at $4 a gal would be a $750 savings. 3% would be over a couple grand. 5%, $3,700. Meger, no matter how you slice it! I'll throw in the towel . (but still only hit the switch when it's lugging!)

 

Try it.....

You could be losing MPGs in Comfort due to low vacuum keeping you out of the sweet spot of the 4.0.

 

Sorry to interrupt, but I've been searching for days now and just can't find it. I thought there was a "Chat" subforum on the CF. Can someone post a link to it for me.

wink wink

 

Yeah, Flintstone. Hijacker.....

 

Bad boy....

 

Funny guys! (look at post 12). That's one of the two times I got sucked into this thread. Nether was my idea!

 

Yep. That's where you hijacked it for sure.

 

 

So it was Cruiser that should be spanked.

 

I can feel the love. Right through the interweb!

 

OK, I found it in post #20! So the TPS is not adjustable, but could be checked. I suppose if mine > "while driving down the highway, it randomly would downshift for a couple seconds then go back." I'd check the TPS. It might be downshifting based on the TPS signal. The ugly fluid could just be confusing the issue.

And, yea, OK Pete, I'll run a few tanks in Power mode. I have numbers for at least the last 5 or 10 tanks to compare the result with.

 

I agree DFlintstone that the throttle position sensor should be verified. Don't want to get "tunnel vision" on the fluid being the only wildcard with this problem Here's more on the throttle position sensor 91-01.
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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 accordingly 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 denied acceptable range causing the ECU to incorrectly fuel the engine. This is noticeable 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.

 

Hi Tom...I found the same values in an FSM, (.2 to 4.8), out the center terminal. As you know the Renix has a flat with a center on the engine side, and a square plug for the trans side. I myself don't even know if HO has two sides. My thought is. that is an engine side test....Idk if HO has a square plug on the trans side. Identifying the terminals and testing the trans side makes sense to me. The readings may be opposite like Renix... It might be ""B" on the square plug, reversed. (4.8 to .2) Again I don't know myself.

 

Ok so I am not sure what the "comfort" mode is. How can this be checked or whatever. Also my tps is brand new. Is tbere still a chance that could be causing the downshifting issue? I have noticed it does it sometimes at low speeds around 35 or so but not as noticeable.

 

Awork, Pete apologizes to you from the bottom of his sole. He might have been confused because you were keeping secret what Jeep you have. Yours does not have a "comfort" switch. (you run in the other mode). It's always a good idea to find a computer and fill out your INFO.

Here testing sensors comes up allot. New or not, if there is a symptom, there is a cause. How many wires come off that new TPS?

And heck, it doesn't sound so severe. Maybe just do the fluid changes and take it from there. See if it clears up.