New Issue, Is It The Tps?

[ParadiseMJ]

After my AW4 tranny swap I've driven the MJ about 500 miles, here and there, around town, out in the woods and on the road...but...I have not yet gotten it out on the highway because I'm leery about this issue.

 

When I start it, it starts and idles fine, the idle however is a bit low, like between 400-600 RPM. When I step on the gas, it hesitates just a tad and then revs like normal. When I take off from a cold start it hesitates a bit and then goes (hesitates up to 900-1000 rpm). When I'm driving along it shifts and runs fine.

 

I've adjusted the TV cable (twice) but when I've tried to adjust the TPS I can't get any reading (as in blank on the digital VMM). I get a small ohm reading from the flat plug, .5, per Cruiser54's instructions. But blank screen in the square connector. I've used paper clips into the sensor and straight pins into the wire. The same procedure on the XJ give me a perfect reading.

 

What am I missing!? Is my TPS shot or do I have a voltage delivery problem??

[HOrnbrod]

Do you have the two connectors the auto TPS has? Do you have the reference voltage?

 

AUTOMATIC TRANSMISSION:

 

RENIX automatic transmission equipped XJs have a TPS with two connectors. There is a flat three-wire connector, same as the manual transmission vehicles have, and it is tested the same as the manual transmission equipped vehicles--FOR ENGINE MANAGEMENT RELATED ISSUES.

 

However, the automatic TPS also has a square four-wire connector clearly embossed with the letters A,B,C, and D. It only uses three wires and provides information to the Transmission Control Module.

 

Key ON, measure voltage between "A" positive and "D" ground. Note the voltage. This is your REFERENCE voltage

[ParadiseMJ]

I followed the procedure in both the manual (book) and the one Cruiser54 posted. I just don't get ANY voltage, as in no reading from the A or B to D when backprobing the sensor. Like I said it drives and shifts fine (except for that little hesitation on acceleration), and that it just feels like it's working too hard to get to speed (which I also attribute to the 3.07 gearing [soon to be remedied]).

[HOrnbrod]

No TPS reference voltage = no output voltage (as I'm sure you know). Just for grins, check the 5V input to the MAP sensor. It's the same ECU supply as the TPS reference, but the ground points are different. .

[ParadiseMJ]

Will do. I was wondering that...if I went back to the connection. I'm pretty sure I have all the grounds from the TCU pinned out and secured...but maybe not. Check in the morning.

 

On the up side I took a drive today on the highway...about 40 miles round trip. Jeep drove nicely. No tranny issues.