Club 80-90 Forums

Engine has been running well bu sounds unhappy recently, lost a bit of sparkle/response to the throttle. I suspect the vacuum unit but sam not sure of best way to check.
With the engine running (tickover from cold), I unplugged the vac pipe from the dizzy and there seemed to be a slight drop in revs but, sucking and blowing on pipe makes no change in engine speed. Does this indicate knackered vac unit? Is replacing the unit a sraightforward job?

Thanks
Nick

Sorry, 1.9 DG 1987
Nick

Quick answer, no, you need to strobe it rather than using subjective criteria like listening

Firstly, has it got the double vac unit, adv. & ret. ? If so which one are you sucking on

More later...

Thanks Harry
Not sure really, only has one vac pipe! Is there any way of finding out without a strobe, I 've read the other threads but am still not clear (!). According to one thread I should be able to see the back plate moving if I suck/blow without engine running but I'm not sure of procedure, I guess that's rotor and dust cap off?
Thanks again
Nick

nrxx wrote: Thanks Harry
Not sure really, only has one vac pipe!

So it's the single (later) type

nrxx wrote:According to one thread I should be able to see the back plate moving if I suck/blow without engine running but I'm not sure of procedure, I guess that's rotor and dust cap off? Thanks again - Nick

Yep, that is a basic test to see if the unit has not jammed up or has a damaged diaphragm.

As has been said though, you could do with getting a strobe on it and checking for correct vac advance timing, even if it is just to eliminate it from your trouble shooting.

From: https://club8090.co.uk/wiki/Pe ... gnition_02

Thanks, will get strobe and check.