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TCU TPS Stall issue *RESOLVED*

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ok the 88 comanche 4.0 automatic efi is stalling


i have the TCU unplugged because i had to move it. its has a bad TPS so i manually shifted it home.

could having the TCU unplugged cause stalling durring acceleration (maybe because the TCC is not giving a signal? [read that somewhere i think])


do you think once i get the new TPS and plug the TCU back up this will stop?


let me know if you need more info.

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ok more detail.. it stalls when i hit the gas. sometimes it recovers (more of a hesitation i guess)


i checked the TPS with a meter but I'm a bit confused about the test..


does the TCU have to be plugged in when setting the TPS? (mine is not)

does the TPS normally go bad, or just need re tuning?

is 60 bucks ok price for the TPS (autozone has them near me)


anyone that has worked on the TPS please feel free to call me, just PM me if you don't mind a phone conversation and ill send my cell number...

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I have not tinkered with the TPS, but considering that unplugging the TCU and shifting manually is part of the FSM procedure for diagnosing tranny problems, it seems unlikely that unplugging the TCU would induce stalling problems. After all, it's a separate computer with a separate harness. How would the ECU know the TCU is unplugged? And why would it care?

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Unplugging the TCU will not have any effect on the engine. I have made a electronic shifter for mine (like a autostick), and when enabled it bypasses the TCU completely.


If your TPS is bad, it can effect not only the trans, but the idle speed as well. The TPS sends signal to both the ECU and TCU. If you look up a TPS for a manual trans, it has fewer wires and only feeds the ECU.


There is a link on this page about 1/3 of the way down for Renix TPS adjustment (and a BUNCH of other stuff too!)


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So i adjust TPS with ABC but i should plug in the TCU first, I just picked up a new TPS (totally returnable if its not the issue) so ill plug the TCU in and check ABC and dot my I's and cross my T's


If i still have an issue what would be the next step ? pull and clean the TB? i am not good at diagnosis of thus kind of stuff

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