Re: 1987 Sprint Greencloverleaf vacuum advance broken
iv done that job
i am running a marelli electronic ignition in an early sud
firstly to check operation just give it a rev while looking at the external bracket that goes from the diaphram to distributor. if it doesnt move then the diaphram is probably split (like mine was)
also (just in case) disconect the vaccum hose and feel for vaccum as you rev the motor .
if you confirm it is faulty you can either replace ,overide or repair it.
firstly, if you buy a new one, can i buy your old one?
secondly if you overide it you will still get most of your advance from the mechanical advance in the distributor. this is ok if its a sunday thrash car but not really if you do high milage and require good fuel economy and smoothness. the key is to ensure you have max advance at high revs 4000+ .the spring in the diaphram should hold things steady but make sure its not fluctuating . you can do this by looking for erratic movement of the bracket or with a strobe light while reving it steady.
thirdly you can repair it like i did. you cant buy the parts so you really have to do it yourself otherwise its too time consuming for a mechanic to improvise and he probably wouldnt be able to guarentee it. i peeled mine open and cut back a large diaphram from an lpg unit and crimped it back together again using a glue to seal it. not very good looking but effective