Mechanical advance bad?

BlackStar
Club4AG Enthusiast
Posts: 135
Joined: Wed Jan 09, 2013 6:49 pm

Mechanical advance bad?

Postby BlackStar » Sat Jul 20, 2013 11:49 am

How can you tell if the mechanical advance is bad on a distributor? The haynes manual says turn the rotor clockwise, and the springs will pull it back to the original position. Mine doesn't do that. When using a timing light, the timing advances with the vacuum hoses attached, and revving the engine(Timing set at 5BTDC) When i take off and clamp of the hoses, the distributor shows no advancing while revving the engine.

Time to take it apart and clean/rebuild it? 1987 SR5

allencr
Club4AG Expert
Posts: 394
Joined: Thu Jan 10, 2013 9:59 pm

Re: Mechanical advance bad?

Postby allencr » Sat Jul 20, 2013 3:04 pm

Yes. Just a few drops of penetrating oil(wd40 is NOT penetrating oil) is usually enough to free it up, but dis-assembly & polishing away the rust/corrosion is necessary for the repair to last.
//
//
Also, forget the timing marks & light BS, go with what runs best - idles smooth & fast, only pings when abused. Checking the advance is the only thing a light is good for IMO.