Setting Points - Why is it so difficult?
 

Hi all,
Why do I find setting point so difficult in my 1968 1800S?

I have always found it really difficult to set the points gap accurately. It seems such a poor set up having to physically rotate the base of the points with a screwdriver. Must have had 4 or 5 separate attempts yesterday before giving up with a dwell reading of 56degrees (from a 0.015inch gap).

I have set Lucas style points with the eccentric screw many times and got it right first time. The Bosch system seems so unrefined.

Am I missing something and is there a better way to set the points gap correctly.

I am tempted to go down the electronic ignition set up (Accuspark) but have been put off due to issues of integration with the armored cable/coil set-up! Maybe its time to bight the bullet.

Phil

Only 4 or 5 attempts? That's jolly good :) It always takes me numerous iterations. It's not the method of moving the points that's the problem, it's the way they like to shift as you tighten the screw...

As regards powering an electronic ignition unit without disturbing the armoured cable... this circuit ought to work, though I haven't tested it.

30 is the live feed to the ignition switch.
54 is the switched live for everything except the coil itself.
50 is the starter control connection.
The relay is a boggo Halfords unit.
The capacitor is to keep the relay energised during any possible hiatus between it receiving a feed from 50 and a feed from 54 as the key rotates. The value 1000uF is a "safe guess". It may work with a smaller value; it may even work without it.
Diodes and capacitor can be obtained from Amazon or ebay probably more cheaply than the minimum order charge from one of the usual electronic component suppliers.
The fuse should be chosen to suit the needs of the electronic ignition module. 10A ought to be OK.

Phil;

If you are setting points (or trying to!), then you will also want to reset timing, and if you are resetting timing, you will need to loosen the timing clamp on Distributor base to allow it to turn, and if it is allowed to turn, then you can rotate it such that Rubbing block of Points is right on a Lobeshaft high-point (in other words, at max gap)... and that is precisely where you want to set your gap.

...and having made setting the gap simple, you may then proceed with Static Timing as described here: http://www.sw-em.com/Volvo%20Ignitio...tatic%20Timing

"...so difficult"...?...not at all IMO!

I suggest you try again, using technique above and you might not need to consider changing to and elec ign...

Good Hunting!

I just pull the distributor out of the car and set the points on the bench.

You're using a good flat screw driver in the notch to open and close the base plate, are you?

My method of doing it is to just loosen the screw enough to be able to just move the base plate, but tight enough that you can run the engine for a few seconds. That way, you can take a reading of the dwell angle and tighten it when its right.

I always set it at the lower end of the dwell angle range (59 degs). Then I periodically hook up my dwell meter to check the gap hasn't reduced giving a reading higher than 65 degs. That way, I get the full use out of a set of points and never have to re-adjust.

If memory serves correctly, there's no need at all to alter the supply, even with a ballasted system, when converting to Accuspark electronic ignition.

Nothing wrong with Pigeons circuit but almost certainly not needed - check with Accuspark that they have a module suitable for a ballasted system though in case i'm speaking out of turn.

Bosch distributors are notorious for closing the points gap despite proper and careful initial setting. Don't forget a smear of high melting point grease on the cam lobes of the shaft to prevent premature wear on the points heel and once you've set the points to where they should be, check the stroboscopic timing and adjust if necessary.

If you want an unobtrusive conversion, it should be possible to find an electronic ignition set up from a later 240/early 740 with the dizzy mounted on the block (as opposed to the rear end of the camshaft) and convert it that way.

Maybe not as cheap as the Accuspark but would be Volvo branded bits throughout. ;) :D

Dave;

"Bosch distributors are notorious for closing the points gap despite proper and careful initial setting." I can't agree...and it's the first time I've heard of that...maybe your initial setting wasn't as "proper and careful" as you thought...I got 50kMiles from one set of points as a long-term test, and I finally changed them out of guilt (and because Centrifugal Advance was frozen)!

See: http://www.sw-em.com/tuneup.htm

Cheers

I tried to swap the 240 gubbins into an Amazon distributor, without success.
A shame because it works brilliantly on the later cars.
Maybe ,if you had suitable engineering connections, it would be possible.
The Accuspark sets I've tried work well on both of our other old classics (Essex V6 and BMC C series), no doubt their Amazon one would too.
I gave up and kept it on points!
And, yes, they can be a bit fiddly, but the twiddle factor is part of running an old car.

I'm speaking from my experience Ron, same as you are but i've seen countless distributors with the points securing screws chewed in a clockwise direction by owners and/or mechanics trying to ensure the gaps didn't close.

At one point in time, the contact breaker sets were sold with replacement screws all neatly packaged with them. I've also attended a high number of breakdowns where the car has become sluggish then suddenly either died or refused to start - first question is when was it last serviced? If the answer is either very recently or quite a while ago, the first point to look at (pardon the pun) is the contact breaker gap if it has a Bosch dizzy.

With the advent of initially Hall Effect and then later Motronic triggered electronic ignition and aftermarket kits, the demise of the contact breaker and condensor was inevitable.

That's why it's barely heard of today but i'm fairly sure that had the internet been around 30-40 years ago, it would have been full of posts from not just Volvo owners but owners of Vauxhall, Ford, VW, Audi, Mercedes, BMW to name just half a dozen asking how to prevent their points closing up.

Despite being known as "The Price of Darkness", Lucas distributors and points never seemed to suffer this problem, it seemed to be a "Bosch thing".

Thanks everyone,
Clearly i am not alone having a problem setting Bosch points.

I am going to try Ron's method which sounds like a possible solution before I go down the electronic route.

Phil