General: 140: - Distributor Help

Dylan144GT · Aug 9th, 2010, 14:16

Hi all

I have a problem. Playing around with the dizzy this weekend, I found something odd ... My distributor has the centrifugal advance mechanism with the springs and weights and all but its not connected to the base plate! So how does it possibly advance the timing? The dizzy is a Bosch JFR4 0231 153 003 non-vacuum advance type. The thing that confirms my confusion is that the mounting plate for the points is a single plate, not two plates mounted on top of each other where the bottom one is screwed to the housing to stay stationary and top one rotates about a lip in the bottom plate and hence advances/retards. Is it some clever trickery that the people at Bosch have trounced me with or am I right in suspecting foul play by a previous owner? Could this be why my car only barely makes 3500rpm?

Can anyone shed some light on this please? I can post a picture of the plate if need be.

Thanks
Dylan

swedishandgerman · Aug 9th, 2010, 16:02

The centrifugal advance system works by advancing the rotor shaft. The faster the shaft turns, the further the springs go out which in turn mkaes the shaft turn around a bit. It doesn't do anything to the base plate.

Very difficult to check the exact operation of the springs and weights, but you can do a simple check that the basic function is working by grabbing the rotor, twisting it about 20 degrees until it won't turn any more, realease it and check there's a reasonable amount of force. If it doesn't spring back or won't move at all, then it's knackered.

On a distributor with a vacum unit, the base plate moves. As you say, the 003 distributor doesn't have a vac unit, so your base plate doesn't move.

Aug 9th, 2010, 14:16	#1
Dylan144GT Member Last Online: May 21st, 2023 08:35 Join Date: Aug 2008 Location: Cape Town	Distributor Help Hi all I have a problem. Playing around with the dizzy this weekend, I found something odd ... My distributor has the centrifugal advance mechanism with the springs and weights and all but its not connected to the base plate! So how does it possibly advance the timing? The dizzy is a Bosch JFR4 0231 153 003 non-vacuum advance type. The thing that confirms my confusion is that the mounting plate for the points is a single plate, not two plates mounted on top of each other where the bottom one is screwed to the housing to stay stationary and top one rotates about a lip in the bottom plate and hence advances/retards. Is it some clever trickery that the people at Bosch have trounced me with or am I right in suspecting foul play by a previous owner? Could this be why my car only barely makes 3500rpm? Can anyone shed some light on this please? I can post a picture of the plate if need be. Thanks Dylan Last edited by Dylan144GT; Aug 9th, 2010 at 14:19.

Aug 9th, 2010, 16:02	#2
swedishandgerman Premier Member Last Online: Oct 23rd, 2023 21:39 Join Date: Apr 2007 Location: EXETER	The centrifugal advance system works by advancing the rotor shaft. The faster the shaft turns, the further the springs go out which in turn mkaes the shaft turn around a bit. It doesn't do anything to the base plate. Very difficult to check the exact operation of the springs and weights, but you can do a simple check that the basic function is working by grabbing the rotor, twisting it about 20 degrees until it won't turn any more, realease it and check there's a reasonable amount of force. If it doesn't spring back or won't move at all, then it's knackered. On a distributor with a vacum unit, the base plate moves. As you say, the 003 distributor doesn't have a vac unit, so your base plate doesn't move.

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