Headlight strobing/flashing and overrun surge finally fixed

[davamb]

Ever since I bought the Cali, it's had this problem with strobing/flashing lights.
They don't flash off/on, just a brightness change.
I got out the oscilloscope and had a look at the voltage,
and there was about 1/2 a volt ripple on the battery line when the motor was running.
The frequency of the ripple changed in proportion to the load;
the greater the load the lower the frequency of the ripple.

Finally decided to see what I can do about this.
First thing was to check/clean all the connections between alternator and battery,
including all the earth strapping.
Did this last weekend with no improvement.
Had been thinking all week it had to be a regulator issue,
so decided to see if I could get to the regulator on the back of the alternator.
If you take off the air trunking and the plenum box,
you can get the alternator unbolted, and have enough room to swing it around to get at the regultor on the back of it (Bosch type alternator).
I removed the regultor (2 screws) and had a good look at it.
The brushes were a bit worn, but still within service limits.
Cleaned these up a little with fine emery
and checked they were free to move in their housings.
There's a small metal tang inside the alternator that makes contact
with the regulator and I noticed this was not terribly clean
(in an electrical contact sense.)
Cleaned this with emery and the mating contact in the regultor module.
Re-tensioned the arm in the alternator and (very carefully)
put the regulator module back onto the alternator.
Put alternator back on, same for plenum and intake.
Voila! Strobing / flashing gone.

Also had had some trouble with surging / kangarooing on overrun,
Periodically I clean out the 2 small hose junctions where they enter the rocker cover and throttle body,
and this seemed to give me a couple of months good running.
For some reason, I'd never bothered checking the pipes.
The previous weekend, whilst checking electrics, I'd done a clean as a matter of course, but still had some overrun surge.
Checked the pipes themselves and the larger of the 2 was really blocked with sludge.
Took quite a bit of cleaning with turps and rag to get this clear and spotless again.
Problem(s) solved, car better than ever. Driver grinning.

Hope this is of use to someone else.