Thread: dizzie springs

Originally Posted by bee utey

If the vacuum advance is connected to the correct port on the inlet manifold/carby it can't increase the idle speed as there's supposed to be no vacuum present. Check the port with your finger for vacuum, find the one that applies vacuum only off idle.

I'd never have thought of that .... Hmmm... I wonder if it's connected to the right port, but the idle is too high, so it's producing vacuum as it thinks it's off idle.... exacerbating the high idle. I'll take a look.

I'd never have thought there should be no vacuum at idle! (given idle is when you have the most vacuum).

seeya,
Shane L.

I had a look around the carbies on all the other cars here ........... I'll be buggered, the design of the pickup means there is no vacuum until the open the throttle off idle. I've been tinkering with cars since I assembled my first ever car when I was about 12years old (a renault 4 out of boxes of parts) and in all the years since have never noticed that.

Anyway, the vacuum advance makes a huge difference. I can let it run down to 1000rpm in 3rd gear through round-abouts now and it pulls away effortlessly with just a touch of throttle.

The advanced unit was plumbed int the inlet manifold, I found a blanked off port on the right hand carby though, that surprisingly ( ) has no vacuum at idle but lots off idle and plugged it on there. The idle plumetted from 15->1700rpm back to 700.

I wonder what the vacuum port on the manifold is for ?? Did the '85s have any ugly like pollution pumps on them that have been removed

seeya,
Shane L.