Club 80-90 Forums

937carrera wrote:Ok, just throwing some ideas out there for you

I’m grateful for any suggestions as I’m totally mystified ( not to mention P#*§ed right off!,)

I’m sure the carb is operating mechanically ok as it nearly new. It’s a Brosol replacement for the Pierburg which is a direct copy. There are only 2 general adjustment screws. The throttle stop and the CO2 idle mixture screw. As I’ve said. I’ve adjusted the idle mixture to within .5% of the VW setti...

I tried increasing the throttle stop screw on the carb and got it running ok. I took it for a run and the revs gradually built to 3000 plus with no throttle so had to pull over and back off the screw till idle speed was ok. Drove home, idled ok, switched off, re-started and back to square one!!

Probably one for Aidan here. Whilst taking a break from my temperamental idling problem and waiting for someone to have a sudden lightbulb moment on my thread, I though I would investigate another niggling fault. I had assumed that a constant and worsening ‘clicking’ from the near side rear must be ...

[quote="937carrera"]Great, so timing is 5 deg BTDC vac disconnected and 10-12 deg BTDC vac conected. Seems like timing and vac advance is working correctly. The fact that it runs fine at 1200 rpm + and the plugs are a good colour does seem to indicate a weak mixture on idle, when you raise...

Just to add. Spark plugs are light grey/beige colour and exhaust is black but not excessively sooty.

Next instalment! Checked timing with vac adv disconnected and plugged. 5 deg btdc . Reconnected and revs rise a bit and timing advances about 5-7 deg All good. (Already Removed and replaced short length of braided flexi pipe off inlet manifold for brake servo) I left ticking over for about 10-mins. ...

Sorry my mistake, I should have just referred to it as vac advance! There is only one pipe which I’ve renewed the 2 flexi sections and ‘suck’ tested for soundness and also that sucking moves the advance in the dizzy. I’ve spent so much time yesterday trying so many different options that I’m finding...

Timing should be set at 5 deg BTDC with vac disconnected (and the hose should be plugged) Reason for asking you to check the timing earlier was to see where it was set and what effect the vacuum advance component of the dizzy was having. I don't think that's all your problem, but it won't harm to g...

And yes the vac was connected when the timing was at 5deg btdc. I reset it without connected at 5deg btdc and then reconnected it and it didn’t make much difference.

Choke is working fine. If I start from cold with one press on the throttle then it’ll idle at high revs until the choke comes off and then it dies if left alone. It will idle warm with the vac disconnected if I start it and kep the revs up and then gradually decrease over about 5-mins. If I manage t...

So what happened?!!

David, the ht leads were all renewed not long ago and they all appear good.

If I start the engine with the adv/ret connected then it’ll idle if I keep the throttle pressed for a while and gradually release after 5-mins or so, the idle speed is set at about 950. If I disconnect the vac pipe it’ll die immediately. If I start without it connected it’ll run after the same proce...

Just checked, there definitely isn’t one!