no 4th gear, why??
04-16-2011, 12:37 AM
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Year: 1994
Model: Grand Cherokee
Engine: 5.2L V8
no 4th gear, why??
pickin' brains here i need help i'm running out of ideas. so my 90 Xj I6 4.0L just started with this new prob recently about 4 days ago. its been doing it to the day. so i start it runs fine shifting through gears 1-4 just fine for about first 30Min or so after it starts getting warm or i lay into it, "at least its what i think" it stops shifting into 4th. i just had my tranny fully rebuilt its legit! i messed arround with my tps sensor thought maybe it was bad connections since i was missing the clips so i hard wired them in. good to go, keeps happening only after i've been driving! so if i let it cool down and sit for about 30 or so its fine again. I dont know whats up? i know its not the tps sensor, not the tranny, i had someone tell me it might be a heat sensor on the cylinder head somewere i took it off purged the coolant. i dunno whats up? any ideas would be much appreciated! TCM maybe?? "Transmission Control Module"
04-16-2011, 06:04 AM
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Year: 1999
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How do you know for sure that it is not the throttle position sensor? It is one of the primary suspects, in my opinion.
They can be tested, but for something that only acts up warm, testing would have to be done when the symptom occurs, or it may test within spec. And also know that the TPS in the 87-90 are adjustable, which can be done with a meter.
If you get stuck, I would definitely try a different TPS before looking to more complex possibilities like the TCU.
They can be tested, but for something that only acts up warm, testing would have to be done when the symptom occurs, or it may test within spec. And also know that the TPS in the 87-90 are adjustable, which can be done with a meter.
If you get stuck, I would definitely try a different TPS before looking to more complex possibilities like the TCU.
04-17-2011, 09:51 AM
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Year: 1994
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Right on thanks man, well the reason why i'm pretty sure its not the tps its because we changed it out twice in one day and it did the same thing after about half hour of driving on the freeway, and for whatever reason going up hill and putting some muscle behind the pedal seems to trigger the symptom as well. i think i'm not to sure but it seems to be that way. so i mean its fine to drive when its not to hot. once it passes 210 or just above it seems to happen. i dont know why?
04-17-2011, 10:49 AM
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04-17-2011, 11:16 AM
#6
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TPS Adjust
Test and adjust your "throttle position sensor". It is directly involved with transmission shifting characteristics. Could also verify adjustment of your TV cable.
Here is a link to the adjustment procedure of the cable and also more on verifying the TPS. Good luck!
http://naxja.org/forum/showthread.php?t=1015963
----------------------------
RENIX TPS
(Thanks to Joe Peters from NAXJA for this information)
MANUAL TRANSMISSION:
RENIX manual transmission equipped XJs have a three-wire TPS mounted on the throttle body. This manual transmission vehicle TPS provides data input to the ECU. The manual transmission TPS has three wires in the connector. Wire "A" is positive. Wire "D" is ground. Remove the three-wire connector from the TPS. Key ON, measure voltage from "A" positive to "D" ground. Note the voltage reading--this is your REFERENCE voltage. Now, reconnect the three-wire connector to the TPS. Key ON, back-probe the connector at wires "B" and "D". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be seventeen percent of your REFERENCE voltage. Adjust the TPS until you have achieved this percentage, if you can't achieve the correct output voltage replace the TPS and start over.
AUTOMATIC TRANSMISSION:
RENIX automatic transmission equipped XJs have a TPS with two connectors. There is a 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 four-wire connector. For the automatic transmission equipped vehicles the four-wire connector provides data to the TCU. Disconnect the four-wire connector. Key ON, measure voltage between "A" positive and "D" ground. Note the voltage. This is your REFERENCE voltage. Now, reconnect the four-wire connector to the TPS. Back-probe the connector at wires "B" and "D". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be eighty-three percent of your REFERENCE voltage. Adjust the TPS until you have achieved this percentage, if you can't replace the TPS and start over.
So, if you have an automatic equipped XJ your TPS has two sides--one side feeds the ECU, and the other side feeds the TCU. If you have TRANSMISSION issues check the four-wire connector side of the TPS. If you have ENGINE issues check the three-wire connector side of the TPS.
For those with a MANUAL TRANSMISSION--the TPS for the manual transmission XJs is stupid expensive. You can substitute the automatic transmission TPS which is reasonably priced.
Here is a link to the adjustment procedure of the cable and also more on verifying the TPS. Good luck!
http://naxja.org/forum/showthread.php?t=1015963
----------------------------
RENIX TPS
(Thanks to Joe Peters from NAXJA for this information)
MANUAL TRANSMISSION:
RENIX manual transmission equipped XJs have a three-wire TPS mounted on the throttle body. This manual transmission vehicle TPS provides data input to the ECU. The manual transmission TPS has three wires in the connector. Wire "A" is positive. Wire "D" is ground. Remove the three-wire connector from the TPS. Key ON, measure voltage from "A" positive to "D" ground. Note the voltage reading--this is your REFERENCE voltage. Now, reconnect the three-wire connector to the TPS. Key ON, back-probe the connector at wires "B" and "D". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be seventeen percent of your REFERENCE voltage. Adjust the TPS until you have achieved this percentage, if you can't achieve the correct output voltage replace the TPS and start over.
AUTOMATIC TRANSMISSION:
RENIX automatic transmission equipped XJs have a TPS with two connectors. There is a 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 four-wire connector. For the automatic transmission equipped vehicles the four-wire connector provides data to the TCU. Disconnect the four-wire connector. Key ON, measure voltage between "A" positive and "D" ground. Note the voltage. This is your REFERENCE voltage. Now, reconnect the four-wire connector to the TPS. Back-probe the connector at wires "B" and "D". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be eighty-three percent of your REFERENCE voltage. Adjust the TPS until you have achieved this percentage, if you can't replace the TPS and start over.
So, if you have an automatic equipped XJ your TPS has two sides--one side feeds the ECU, and the other side feeds the TCU. If you have TRANSMISSION issues check the four-wire connector side of the TPS. If you have ENGINE issues check the three-wire connector side of the TPS.
For those with a MANUAL TRANSMISSION--the TPS for the manual transmission XJs is stupid expensive. You can substitute the automatic transmission TPS which is reasonably priced.
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