Vacuum advance / retard

[red griff 500]

After hooking up a strobe to my Griff, I noticed that the vacuum advance/retard had no effect on the timing i.e. when you blip the throttle the timing only changes slowly which is consistent with only the speed advance mechanism.

I haven't fiddled with engines for years, but my memory is that you should see an immediate change in timing due to the reduction in vacuum (i.e. opening the throttle butterfly reducing the vacuum) causing the diaphragm to move the linking rod, and also independently, the speed mechanism changing the timing proportionally with engine speed change.

I cannot get the diaphragm/mechanism to move by sucking the attached pipe, and again my memory is that you should be able to pull enough vacuum with your mouth to move this.

Although I haven't driven the car since fixing a coil problem (during which I dicovered this "problem") the engine responds well to blipping the throttle i.e. no hesitation.

All contributions gratefully received

Steve

[wixer]

Have you got a one way valve on your vacuum pipe ?? If so, check it's fitted the correct way around.

[red griff 500]

Thanks Grirter - yes the valve is fitted. I'll check to see if it's fitted the right way round.

[red griff 500]

red griff 500 said:

Thanks Grirter - yes the valve is fitted. I'll check to see if it's fitted the right way round.

What the hell did I type Grirter for? I meant to type Grifter, but I was wrong there too.

Thanks Wixer is what I should have said!