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shifting issues

K

korn9613

NAXJA Forum User
Location
deer park, wa
tryingto figure out if my transmssion is hosed or justa linkage problem. i hammer the throttle and it feels like it barely kicksdown, but no more speed picked up, i lose speed on hills. this just started. im wondering if my kickdown somehow got hosed up or if that meansthe tranny is toast, manually going through the gears it seems fine! any ideas on what to check would be greatly appreciatd. transmissions scare me.
 
I would say it's undergeared but if it just started and you didn't change tire size then that's not it.

Does it feel like it's slipping in any of the gears? What speeds are you having problems?
 
I had a friend with a stock '97 XJ. He had washed his engine off with high pressure water and afterwards he had a similar problem to yours. He replaced the TPS (throttle position sensor) located on the throttle body, and his auto was once again shifting properly.
 
well its been weird. yesterday on the way to work it would stay in 1st or 2nd until i hit a certain speed, then it would shift into third, sounded bad because going through residential i was doing 25-30 mph but at around 3000-3500 rpm, i would hammer down and it would shift out into third. well- on the way home last night, i could barely pull a hill. i would stomp it and it felt like it wasnt kicking down at all(stuck in third). i thought i felt it trying to kick down but their was no improvement in speed or power.
 
korn9613 said:
trying to figure out if my transmission is hosed or justa linkage problem. .
Click to expand...

Care to share any details about your Jeep ? Year, engine, trans, tire size ?

The most logical suspect is the TPS. It can be tested for proper function.
 
Tim_MN said:
Care to share any details about your Jeep ? Year, engine, trans, tire size ?

The most logical suspect is the TPS. It can be tested for proper function.
Click to expand...

x1,999,999,999,999
 
im sorry- its an 89 cherokee, 4.0 auto. toyota rear end locked, early bronco dana 44 front end, open. im running 33's on it. i dont know if it helps pin point a problem but if i do the shifting manually, it is just fine, if i put in drive, it shifts goofy. are you thinking it could still be a tps issue? wouldnt that effect idle as well?
 
TPS is still the primary suspect here. A bad TPS does not necessarily give a bad idle as there are two ribbons inside your TPS. One ribbon provides input for the ECU and one provides input for the TCU..
It can be checked and adjusted with an analog voltmeter.
 
cruiser54 said:
TPS is still the primary suspect here. A bad TPS does not necessarily give a bad idle as there are two ribbons inside your TPS. One ribbon provides input for the ECU and one provides input for the TCU..
It can be checked and adjusted with an analog voltmeter.
Click to expand...

Definitely check and adjust the TPS.

Other "free" things: adjust the throttle pressure cable--its not a kickdown cable--it effects pressures in the transmission in relation to throttle position; adjust the shifter cable; adjust the NSS--not just a neutral safety switch--it provides data to the TCU on physical gear selection.

There is a term, TOLERANCE STACKING, where a little harmless slop here, some more over there, pretty soon its a nightmare. You can't adjust the NSS correctly until the shifter cable is adjusted correctly.

As your trans shifts manually Ok that means the mechanical/hydraulic aspects are in good working order and the problem lies in the electronics.
 
Search "adjusting TPS*" without the quotes.

OR

Go here: http://www.lunghd.com/On_Site_Tech.htm and scroll down the page to bottom of the section titled "Engine, Fuel System, Cooling & Exhaust" and you will see "Basic Renix..." and "TPS adjustment...", follow them and you will get all of your questions answered.

Bookmark this website, it is a treasure trove of info.
 
im having the same issues if i manual shift ill go through the gears just fine but if i put my tranny in drive and step on it its climbs really slow i adjusted my tvr cable and also replaced my tps sensor and nothing checked my fluid fluid levels are good and also rebuilt my nss and nothing anyone have any other ideas?
 
FOR SPEEDBUMP96:

First, did you unplug the TCU and shift it manually that way? You would get 1st in 1-2; 3rd in 3; 4th in D, and reverse.

If you did that, and got that result, then the problem is electrical. If you did not get that result, your problem is mechanical/hydraulic.
 
Last edited:
joe_peters said:
First, did you unplug the TCU and shift it manually that way? You would get 1st in 1-2; 3rd in 3; 4th in D, and reverse.

If you did that, and got that result, then the problem is electrical. If you did not get that result, your problem is mechanical/hydraulic.
Click to expand...

i can shift manually with the tcu hooked up when i keep the tcu hooked up and put it in d if feels like it goes into second instead of dropping all the way down to 1st gear
 
FOR SPEEDBUMP 96:

Yes, I know you can shift manually with the TCU hooked up, but the unplugged TCU test is the ONLY way to isolate if the issue is electrical or mechanical/hydraulic. Once you know, then you know if you need to pull the transmission or not.

IF the issue is electrical, then you have narrowed the field--TPS, TCU, TCU power, NSS, solenoids, and any of the wiring in between.

Now, as the NSS provides data to the TCU on the physical gear selected, you have to first adjust the shifter cable. Once the shifter is adjusted, you have to adjust the NSS (a**uming it is working) to get good data to the TCU.
 
joe_peters said:
FOR SPEEDBUMP 96:

Yes, I know you can shift manually with the TCU hooked up, but the unplugged TCU test is the ONLY way to isolate if the issue is electrical or mechanical/hydraulic. Once you know, then you know if you need to pull the transmission or not.

IF the issue is electrical, then you have narrowed the field--TPS, TCU, TCU power, NSS, solenoids, and any of the wiring in between.

Now, as the NSS provides data to the TCU on the physical gear selected, you have to first adjust the shifter cable. Once the shifter is adjusted, you have to adjust the NSS (a**uming it is working) to get good data to the TCU.
Click to expand...

yeah ill give it a shot tommorow mny tcu is turning on my backup lights so im assuming that it is working i will check it out tommorow i appreciate all the help i will keep it posted so i just disconect the tcu and manually shift through the gears? and if it shift then i know my problem is electronic?
 
Speedbump96 said:
yeah ill give it a shot tommorow mny tcu is turning on my backup lights so im assuming that it is working i will check it out tomorrow i appreciate all the help i will keep it posted so i just disconnect the tcu and manually shift through the gears? and if it shift then i know my problem is electronic?
Click to expand...

Correct, if it shifts like I posted above with the TCU unplugged then the issue is electrical.
 
joe_peters said:
Correct, if it shifts like I posted above with the TCU unplugged then the issue is electrical.
Click to expand...

yeah i pulled the tcu plug still its not downshifting when i put it in d but if i manually go through the gears it shifts perfectly so that would be my tranny aka mechanical correct?
 
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