[Cliff R]

A well located ported source is required. Using manifold vacuum, the TCC will stay locked up when coasting, locked up at part throttle, and unlock at heavy/full throttle.

Using a ported source, it will only lock-up at part throttle. Any heavy/full throttle will unlock the TCC, it will also unlock when coasting.....Cliff

[HWYSTR455]

Got it. Yeah, figured I was missing something there! I was stuck on using manifold/full-time since a number of the controller/wiring docs state if you have cycling to use the delay and go full-time. Ported makes sense, and will do so.

[Cliff R]

Yep, the ported sources works perfectly. Some folks don't understand how ported vacuum works. Basically, it only applies at light throttle/light load. The only real difference between full manifold vacuum, and ported, is that manifold vacuum will have a signal at idle or anytime the throttle plates are closed. Since the source location for a ported source is just above the leading edge of the primary throttle plates at idle, it is uncovered, or activated with the slightest movement of the throttle, and from there on up represents the same reading as any manifold source which is also below the throttle plates.....confused yet?......Cliff

[HWYSTR455]

Nope, totally understand how ported works, but thank you for the refresher course! My problem was brain-lock! No two ways around that! Heh-heh! Hey, but I'm NOT old!!! I was thinking down the road of full-time because I was planning on using the GM vacuum delay.