90 tracker:  in pulling the motor and testing everything i tested the vacuum on the dis vacuum advance.  it moves just fine but will not hold vacuum.  i asked around and was told that some are suposed to and some are not.  anyone know if my advance unit is good or bad before i spend $68 for a new one, or $145 for a whole rebuild dis?

my 89' didn't hold vacuum, so I got one that did
thinking the turbo blew it out, but now the new one
does the same thing   I just live with it.

I'll try to dig a little deeper, but FWIW, a quick glance at the shop manual test of the vac advance only talked about "smoothness" of motion, not whether it would hold vacuum or not.

a quick glance at the shop manual test of the vac advance only talked about "smoothness" of motion, not whether it would hold vacuum or not

ya, that is why i posted this!  thought that was strange :-/  

thanks, guess maybe its normal

I have an '89 sidekick and the vacuum advance unit does not hold vacuum.

It also sort of clicks from one position to the next.  Is this the opposite of what's described as "smooth" in the manual or is this acceptable?

I have an '89 sidekick and the vacuum advance unit does not hold vacuum.

It also sort of clicks from one position to the next.  Is this the opposite of what's described as "smooth" in the manual or is this acceptable?

I'm an idiot.  It was clicking in time with me pumping the vacuum pump.

Checked out a few vacuum advance units at the junkyard: none of them seemed to hold vacuum.  So that answers that.

I'll check mine when I get home.  It's an 89 1600 8-valve in a sami.  All I know is that GM HEI distributors are DEFINITELY made to hold a vaccuum.