Jump to content

Matchbox dizzy testing


edekalil

Recommended Posts

  • Replies 10
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

They are particularly fussy about grounding, so make sure the distributor has a good ground to the engine, and the engine has a good ground to the chassis/battery.   Replace wiring/cables as needed.  You can crank the engine to test the distributor.  Look for 12+V at the coil + terminal, and a cycling 12/0/12/0/12/0V at the "-" coil terminal when cranking.   Its easier to see with an analog multi-meter.  You have to get the distributor up to about 200 rpm (cranking speed) to get a consistent test signal.  

 

If it doesn't function, the module is either not grounding OR the pickup isn't working.  I can diagnose the pickup by simply running it through a pulse amplifier on my Sun tester.  Or you can build one using an HEI module from a Chevy distributor.  There are plans online.  Basically the pickup wires to the small terminals, the larger terminals get power and coil - signal.  Ground goes to one of the screw holes on the end of the module that has the small terminals.  

  • Like 2
Link to comment

The only issue I've ever had / am having with matchbox distributors is slopply shaft causing high rpm flutter. The one in my car has started doing it, it's got the telltale wavy/bouncing tach needle. Granted my motor sees 8000 rpm + on a regular basis so that probably doesn't help.

 

Distributor guy what's the availability of parts to repair these? The one in my car was the last good one I had.

  • Like 1
Link to comment

Tom the L series is different than the A in that the distributor just slides down on top of the spindle. There's got to be some slop doing it this way also. I remember someone saying they put an aluminum beer can pull tab on top and pushed the distributor down on it to remove the slop. The Z24i and the KA engines used a CAS distributor and the top of the spindle and the matching part on the distributor were splined. This stabilized the spark timing which was needed on these EFI engines for better management.  
 
co2PNK2.jpg
 

 

TLJF7Cl.jpg

  • Like 1
Link to comment

Mike I knew that but as I'm an A-series guy I think the world works as mine does...........I'm looking into converting to crank triggered ignition as I have some of the parts.........but there is no reason why a distributor can't work properly, mine have when they weren't worn out.

  • Like 1
Link to comment

 

Distributor guy what's the availability of parts to repair these? The one in my car was the last good one I had.

 

The few parts that are available commercially are Chinese knock-off junk.  I make shaft bushings and typically reuse advance springs as they are extraordinarily well made and the posts are adjustable.  The electronics don't exist, so adapting to an HEI module is a legitimate option.  We run the points distributor in our race truck.  The signal is cleaner above 7500 rpm.  

  • Like 1
Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.