[HWYSTR455]

Well, the vacuum switch has an adjustment range of 1-6 inches, and can be wired to open or close when it reaches the threshold. So, if it were to go open when it reaches 6 inches, such as under heavy throttle, that would be desired, though in a coasting situation, wouldn't it be a high vacuum reading? Meaning I wouldn't have both, only one or the other, which is why I was thinking a throttle position or switch for coasting. Or am I overlooking something?

[Overkillphil]

I played around with the TPS idea a while back, but there was some problem using that. Can't remember if it was the TPS relaying the open signal through the computer or adding a relay or something. Probably solved without alot of difficulty but I didn't want to spend any more time on it at the time.

I do notice how our Buick GN's unlock when the throttle is closed. However, I believe even those are also speed referenced, meaning they don't open once a certain speed is reached causing the TCC to remain locked even when one lifts off the throttle. But not 100% on that. FWIW.

[Malky]

If the vacuum switch is connected to ported vaccum on the carb, not manifold vacuum, the vacuum will be drop to zero when the throttle plates close on coasting and unlock the converter.