Ticking Noise Update...ABS Related?
 

An update on the ticking noise which seems to pulse at about half the crank speed, and only audible in first or second gear, sometimes while in neutral - at rpm's between 1400 and 2000.

Car is an '87 NA.

The sound goes away when the brake pedal is applied - and I'm thinking that there might be some sort of erroneous ABS signal causing this.

Does this ring any bells for anyone?

I doubt it’s abs related and pressing the brake pedal also affects the vacuum circuit and there is vacuum to a lot of components including fpr, damper and icv all of which can “pulse”.

It seems like you’re getting somewhere though but you’ll need to investigate one-by-one until you find the culprit.