A442F can't decide what gear it wants to be in

[ubguessin]

90-92 the cable controls line pressure, shift points and lockup. 93-97 the cable only controls line pressure and the ecu decides shift points and lockup. Defiantly important to adjust the cable correctly though to make sure you don't burn up your new trans with low line pressure, too firm is better then too soft.

I am kind of confused because I purchased the nomad VB which is supposed to provide firmer shifts. I drove the truck home today 5 hour trip. Before I left, the kickdown cable definitely had slack and was about 1mm of gap. I tightened the slack out of the cable and am closer to the 4-5mm gap almost to the end of the adjustment threads. I am not noticing any firmness in the shifts with a tighter cable.
Over the course of the trip I had very little "erratic" shifts. Essentially the erraticness was most prominent with a cold engine and light throttle between 18mph-25mph and 40-50mph. Once everything was warmed up the erraticness went away. I believe it shifts way too early out of first gear as well, hardly 200rpms over idle and it goes to 2nd. I am chalking this up to TPS..I will know so much more once the new one arrives Monday and I can get it installed.

 

[Squash]

You do realize that your tranny relies on a temp sensor which disables D/4th gear until the transmission has warmed up.
With that in mind drive accordingly!
If you've driven stick shifts in the cold you will also notice that some gears are harder to engage until the transmission has done some work.
BTW
TPS should have two screws and a paint mark...you can loosen the screws and manually adjust the TPS by rotation.

 

[TheBussman]

You do realize that your tranny relies on a temp sensor which disables D/4th gear until the transmission has warmed up.
With that in mind drive accordingly!
If you've driven stick shifts in the cold you will also notice that some gears are harder to engage until the transmission has done some work.
BTW
TPS should have two screws and a paint mark...you can loosen the screws and manually adjust the TPS by rotation.

it's based on engine temp not transmission temp.

 

[TheBussman]

I am kind of confused because I purchased the nomad VB which is supposed to provide firmer shifts. I drove the truck home today 5 hour trip. Before I left, the kickdown cable definitely had slack and was about 1mm of gap. I tightened the slack out of the cable and am closer to the 4-5mm gap almost to the end of the adjustment threads. I am not noticing any firmness in the shifts with a tighter cable.
Over the course of the trip I had very little "erratic" shifts. Essentially the erraticness was most prominent with a cold engine and light throttle between 18mph-25mph and 40-50mph. Once everything was warmed up the erraticness went away. I believe it shifts way too early out of first gear as well, hardly 200rpms over idle and it goes to 2nd. I am chalking this up to TPS..I will know so much more once the new one arrives Monday and I can get it installed.

your cable was probibily tight "enough" if you want to do an experiment unhook the cable and do a short test drive, you should feel shift flare (don't do this very long it will tear up the trans) tps is an easy one to check with the scope if you have it. If there aren't any dead spots in it your OK. If you decide to replace it anyway be sure to set it to the FSM specs with a 5v power supply, it's not as easy as the 4 pin TPMS on the gas motors with the Idle switch.

 

[ubguessin]

your cable was probibily tight "enough" if you want to do an experiment unhook the cable and do a short test drive, you should feel shift flare (don't do this very long it will tear up the trans) tps is an easy one to check with the scope if you have it. If there aren't any dead spots in it your OK. If you decide to replace it anyway be sure to set it to the FSM specs with a 5v power supply, it's not as easy as the 4 pin TPMS on the gas motors with the Idle switch.

What would I need to do to check the TPS with a scope? What to hook up to and settings in scope?

I took the TPS off today and hooked it up to 5v and read the voltage while sweeping the sensor. You could hardly notice a problem. I switched to reading the Resistance and this is where you could really tell there are errors.

 

[TheBussman]

What would I need to do to check the TPS with a scope? What to hook up to and settings in scope?

I took the TPS off today and hooked it up to 5v and read the voltage while sweeping the sensor. You could hardly notice a problem. I switched to reading the Resistance and this is where you could really tell there are errors.

If you found problems in resistance then there is no need to scope just replace it. To check you could set the scope to 5v, then set the time base as slow as you can, then sweep the throttle and check for dead spots.

 

[charlay61]

If you found problems in resistance then there is no need to scope just replace it. To check you could set the scope to 5v, then set the time base as slow as you can, then sweep the throttle and check for dead spots.

I've replaced my TPS last year. It had a dead spot while measuring the resistance. I would always get a weird 2-3rd shift at exactly the same spot in town as i was always accelerating the same way. One little tip, i did adjust my TPS "a bit further" so that i can "lug" the engine a bit more before it downshifts. It now drives like a proper diesel.