Auto shifting at 3400 at WOT. (1 Viewer)

[lumbee1]

My engine was rebuilt in the fall of 2021 and I installed a supercharger in the fall of 2022.
After installing the supercharger, normal operation has been great however under WOT the transmission shifts at 3400 rpm (PWR not engaged).
I've adjusted the throttle cable (kickdown) based on recommendations from the forum, not the FSM.
The throttle body valve throw has been set to maximize sweep and the TPS has been verified to be in spec and IAC and TPS are Toyota OEM.

FSM describes shift points too soon as being possibly

• TPS circuit
• Pattern select switch ciruit
• No. 1 vehicle speed sensor circuit
• No. 2 vehicle speed sensor circuit
• ECM

Kickdown to a lower gear has always required more foot pressue than I feel is necessary but even then it won't hold the gear to redline. I have not tried manually shifting at redline.

Any suggestions for what to look for next?

BTW, the throttle cable was a discontinued part but they are appearing on ebay again.

 

[BILT4ME]

My engine was rebuilt in the fall of 2021 and I installed a supercharger in the fall of 2022.
After installing the supercharger, normal operation has been great however under WOT the transmission shifts at 3400 rpm (PWR not engaged).
I've adjusted the throttle cable (kickdown) based on recommendations from the forum, not the FSM.
The throttle body valve throw has been set to maximize sweep and the TPS has been verified to be in spec and IAC and TPS are Toyota OEM.

FSM describes shift points too soon as being possibly

• TPS circuit
• Pattern select switch ciruit
• No. 1 vehicle speed sensor circuit
• No. 2 vehicle speed sensor circuit
• ECM

Kickdown to a lower gear has always required more foot pressue than I feel is necessary but even then it won't hold the gear to redline. I have not tried manually shifting at redline.

Any suggestions for what to look for next?

BTW, the throttle cable was a discontinued part but they are appearing on ebay again.

If you have an original cable, even if it's broken, you can ship it to www.inlinetube.com and they can make you a one-off, non-refundable replacement part. If it needs to be shorter or longer, specify how much and they can make it that way.

 

[baldilocks]

Do the FSM specs pertain to a super charged engine? Maybe the ECM is sensing ample power/torque available to do the job that your foot is asking it to do at a lower rpm; in other words, in a higher gear.

 

[lumbee1]

If you have an original cable, even if it's broken, you can ship it to www.inlinetube.com and they can make you a one-off, non-refundable replacement part. If it needs to be shorter or longer, specify how much and they can make it that way.

I certainly appreciate the option but this seems more like something that needs adjustment rather than replacement. Per the FSM the TPS seems to be the blame for numerous issues and I've considered just loosening the screws and adjusting it to the upper limit and lower limit to see what difference it makes.

If it is the kickdown cable, Toyota Parts Deal says this will work:

Toyota 35520-60111 Cable Assembly, Throttle​

35520-60111 - Toyota Parts Deal

www.toyotapartsdeal.com

 

[lumbee1]

Do the FSM specs pertain to a super charged engine? Maybe the ECM is sensing ample power/torque available to do the job that your foot is asking it to do at a lower rpm; in other words, in a higher gear.

That's a great point but there are other supercharged Cruisers that don't seem to have this issue.

I am considering replacing the kickdown cable based on previous experience with kickdown before the engine rebuild, after the engine rebuild, and after the supercharger. The Cruiser always seemed reluctant to downshift or hold the gear past 4000rpm.

 

[lumbee1]

Before ordering a replacement kickdown cable (35520-60111), I figured I would try adjusting my kickdown cable to its limits. This definitely helped and a stretched kickdown cable seems to be the issue, but I might still need to replace the cable.

Many years ago, I followed the FSM spec for the kickdown cable and kickdown required more accelerator pressure than I thought was necessary. Fast forward a few years and my kickdown cable has been adjusted way out of spec but actually required significantly more accelerator pressure for kickdown. With the cable at maximum, it's now correct but the concern is the cable is continuing to stretch and would still need to be replaced. Either way, I have a solution and a replacement is only $60.