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converting conventional points ignition to hall-effect in c900 - possible?

Hi everyone,

I'm looking at figuring out what's involved to replace the conventional points ignition currently in my 1983 900S (8V, n/a, auto box) with hall-effect breakerless ignition as featured in C900's imported into Australia from 1985 and later.

As far as I can tell, the main changes would be:

- replacing the distributor or rebuilding it with retrofit hall-effect sensor components,

- replacing the coil if the breakerless ignitions require a coil with a different resistance value,

- installing either the Saab OEM (or 3rd-party) electronic ignition module or a 3rd-party equivalent,

- wiring it all together.

I have not been able to find any source of parts to retrofit the existing distributor in my car to become a hall-effect breakerless version, so using one for a 1985 or later model of 8V engine might be the go. I'm also researching where hall-effect components can be sourced from in case something is available via a non-automotive supplier.

The coil issue is pretty simple - either it needs to be replaced with one that has a different resistance or it can be used as-is. Will determine that as I go.

The electronic ignition module will be interesting. Apart from the Saab (ie. Bosch) one and it's 3rd-party copies, there are other ways to go here. I've seen some commercial units that I found via some googling. Also, there are projects for breakerless ignition systems which have been featured in electronics hobby publications both here in Australia and in other countries, but the big issue with any of this still comes back to dealing with either replacing or retro-fitting the existing distributor.

I'm a die-hard electronics enthusiast so constructing an electronic ignition kit is no drama... As any example of something available locally in Australia, check out the Jaycar Electronics kit # KC-5247 at this link:

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Being in Australia and supportive of our local electronics enthusiast community, I would prefer to build one of those kits and install it in my car in preference to buying a commercial solution, unless the commercial solution comes with the parts to retro-fit the existing distributor and these part aren't easily obtainable from any other source. 8-)

Regards,

Craig.

Reply to
Craig Ian Dewick
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Do not know much about this on Saabs as all of the ones I have worked on have electronic ignition, but the big deal is getting a place to mount the hall effect sensor and shutter wheel. If you can find a Saab HE distributor that bolts up, go that way - It'll be easier. The Bosch system uses the distributor and an 'amplifier' to trigger the coil. The only question is if the system uses a resistor in line to the primary side or not. This should be well documented in a manual (Bentley or Haynes). Find one in a junkyard and get the whole system including the portions of the harness necessary.

KeithG

Craig Ian Dewick wrote:

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Reply to
KeithG

Craig - sourcing your bits give A-Twins Spares at Girraween a try. No guarantees but they have some 900 stuff & they're close. Just don't try ringing at lunchtime!

Reply to
hippo

Hey John!

I've located a used hall-effect distributor from a 1985 Saab 900 and I will use that as a starting point to work out what else I need. I'll give the company you've mentioned a call too and see what they have got available.

On Friday I purchased one of the Jaycar electronic ignition kits that I mentioned in the original posting and on reading the documentation, it can be set up to trigger from points set up, from a reluctor set up, and from a hall-effect set up, so it's quite versatile. When it's built up, the diecast metal box containing the electronics of the kit can bolt into the same place that the Bosch hall-effect ignition module is mounted in C900's which had it fitted from the factory...

I have noticed that the Siemens HKZ-101 hall-effect vane sensors used by Bosch in the 1980's hall-effect distributors is no longer available, but I've been exploring data about hall-effect vane sensors from Honeywell and there are a couple of products there which look promising so I may order some samples and experiment with the soft-iron 4-slot vane out of a used hall-effect distributor with a Siemens hall-effect sensor.

From some of the info discovered through Google searches, it seems that the most suitable Honeywell sensors operate in reverse (electrically) to the Siemens sensor, but that won't be a problem providing that the triggering points of the sensor can be kept the same. Adjusting a stock Bosch hall-effect trigger vane would be easier than making one from scratch. 8-)

Regards,

Craig.

PS. For those in the know, what are the most popular methods of replacing the seals which go between the rear light clusters and the body metalwork on a non-hatchback C900? The rear light clusters on my 1983 900S are on their last legs and are leaking significantly when it rains, letting water into the boot space. I also need to look at replacing all the door seals as they are leaking too (the left rear footwell gets very wet when it rains), and also the internal door skins on the two front doors are looking quite sad. Can a Saab dealer take care of all this on a C900? Are there any 3rd-party places (preferably in Australia!) that make seals/gaskets/etc. for light clusters, doors, windows, etc. on these cars?

Reply to
Craig's C900 Workshop

Try a skinny bead of black silastic around the mount. You'll only need to take it off again if you smash a lens, 'cos you can do all the bulbs from inside the boot.

Make sure it's not water coming in from either the left rear wheelwell or a missing boot / rear floorpan grommet before you start replacing seals. Pull everything out of the boot after some rain (like now maybe?) and check. If there's 10cm of water sloshing round in there, it can come in under braking. I know ...!

Wreckers. Check the servo on the lhs of the nasty bend coming out of Katoomba on the way to Medlow Bath. He's had 99s and 900s in there on and off forever - worth a shot. Check Parramatta Peestige as well but be prepared to pay top dollar. May be a bit old for A-Twins. Also worth speaking to Greg at Continental Cars at Punchbowl (Citroen but used to wreck/repair Saabs & may still have parts). Motor trimmer or diy with masonite & a matching fabric are your other two choices. Not cheap options.

Probably too small a volume to bother, but as a longshot, see if Savage Rubber are still in business and speak to someone there. Also worth speaking to Mildren's. They cleaned out heaps of ancient spares when they moved years back but you never know ...

Yes - if parts avail and you throw enough money at them. You joined the club a while ago didn't you? Try a classified with them. Cheers from the South Coast

Reply to
hippo

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