"123" Programmable electronic ignition

[asneddon]

17 sounds high. I'm at 10 and get runon if set >15. I have a d cam though. I guess the b20a has a c cam? I'm not sure but isn't the spec for that 4 degrees at idle?

[TomTom]

Actually an 'A' cam. Interested what others have set their static idle to.

Thanks

Tom

[Volvo Canadian]

Hi - You should be at 10 degress BTDC at idle - maybe a little less if you have your engine breathing better.

Do you have a 123 Tune, or the regular one? It sounds like you have set the static timing yourself, then the 123 is ahead of the game until the revs build-up and the advance stops advancing? I believe the 123 reaches max advance of 34 degrees at 2000 rpm. Is the engine running hot? Does that sound right? I'll be surprised if dropping the static advance doesn't fix the problem.

[Volvo Canadian]

Originally Posted by asneddon

I had a spare hour this morning. Wife and baby went shopping, so my 2 and 4 year olds 'helped' me fit it.

Took about 45 minutes, most of which was soldering and heatshrink work.

I built a standard curve with 0deg static because I'm not 100% confident in my timing torch. It all went extremely easily and fired up on the button.

As has been said before, idle is smoother. I haven't taken it for a run yet so don know anything about drivability. I also didn't get a dyno run first which is a shame.

Should. Be easy to swap back if required.

Hey, 45 minutes,that's great!! I am currently 100 miles from nowhere drilling an oil well in NW Canada. The car is going to have to wait until I get a break.

I'd love to hear how things develop - what you tried, what works/doesn't work, as we have pretty similar engines. Where did you connect your vacuum on the manifold? What did you use for your max advance? What rpm?

FYI, check your ignition wires - the 123 gives a higher-voltage spark. And your coil... how to check resistance (anybody)??

[asneddon]

Well, two days of commute, so about 60 miles on the 123 now. Still havent taken it to get dyno'd or anything, but then there is probably no point as I'm running a standard curve. I dont want to spend the time and money until I get new carbs in.

I would say the most noticable thing is the idle. It really is a lot smoother. Sometimes with the old ignition I would end up with a high idle after revving the car higher than usual. Say going up a hill in 3rd with foot flat. Idle would stay at about 1200rpm rather than my normal 900rpm. That seems to have fixed itself, which is good as I always blamed the carbs for that!

Also, the car warms up a LOT faster. I use to be at full temp about 2/3 of my way to work, now its 1/3 of the way. This suggests a fatter spark I guess.

There is also my 'test' hill where there is a very sharp corner part way up. I could just get around that in 3rd, but would pink. Now I can just get around in 3rd, but no pinking. This is a good thing.

On the downside, I stupidly got distracted and topped up my oil twice. Its now over full which is annoying. The level is now covering the word 'MAX' rather than just to the | max line. Bugger! This probably isnt good for an apples to apples comparison as I guess I'm going to be getting fouled plugs.

About fitting times. I soldered and heatshrinked on a period connector, and changed the wires so they were coloured to suit the volvo (eg, white for coil neg rather than black from the 123) so I could easily swap back my old dissy if something went wrong. That took me about 30 minutes as I had to let my wee helpers have a go. My 4 year old is a supprisingly good at soldering! I'm going to have to break out the welder and see how they go at that. If I just soldered the wires in then I would estimate 15 minutes to fit. It really is that easy.

I haven't fitted the vacuum advance yet. I do have a nipple on my #2 carb, so thats just a matter of finding a bit of tube. I want to run nice shinny small bore copper pipe with hose connections at either end, but haven't found a supply yet. I probably have an old mechanical temp guage somewhere I can butcher for that if I get the urge. Its lasted 48 years without vacuum advance, so I guess another week isnt going to hurt.

One of these days I'm going to have to bite the bullet and get a new battery for my laptop so I can have a decent play. It would be nice if there was a usb to bluetooth adapter and an iPhone app!

[Volvo Canadian]

Hi - that's sweet. Whenever you get a chance to play with the settings a bit, I'll be glad to hear about it.

Are you seriously thinking about a dyno? I'd love to compare notes on that! However, my chances of getting on a dyno anytime soon are looking slim. As a matter of fact, my chances of getting home to even touch my car are looking slim, but I'm determined to do it!

I don't know if I mentioned it, but this car is going to go across the country this fall.

[asneddon]

The dyno isn't a big deal. Costs nzd30 for a run at pretty much any non-franchise garage. That's about £15. I don't do full max rev runs. No point as I don't tend to rev over 4500-5000. It's a good way to ensure your mixture is good at all revs ranges and loads. The gas analyser does cost extra though. I think it's nzd20 from memory.

[asneddon]

Its taken a while (as I've been using the modern recently), but Ive used a full tank of petrol on the 123Tune now. I normally average about 23MPG over the last 1000miles. This tank is a new low at 18.21MPG!!!

I think somethings wrong

Anyway, its probably my carbs. I have new RN needles on order from Brookhouse, should be here in 10 days or so (along with new shocks to replace my 3 year old Koni Classics - Dont ask).

I thought I should update my experiences.

First, about the idle staying smoother. I was wrong. Its started gaining revs after a bit of spirited driving again. Idle is at about 1200rpm after a good run, up from 900-1000rpm normally. Oh well.

I have the 123 hooked up to a continous live feed on the fuseblock, not through the ignition switch because of the hastle of the armoured shield. This hasnt caused a flat battery or anything, and I went about 7 days without driving it once. Thats a record for me I think. Current draw of the 123 with the engine off is 66.5mA.

I didn't tighten up the cover screw for the USB connection tight enough, and managed to loose it after about 70 miles. That sucks because it was very nicely made. I have a rubber grommet in there now because I'm going to solder up a nice waterproof USB fly lead.

Also, I pulled the plugs today to see what was happening to my MPG. I've not seen them like this before. The photo is bad, but the base is a little sooty but there is a very distinct switch to a light grey/brown about half way up the earth leg. Are there any plug reading experts on here?

If I do the normal lift of the SUs piston, I get a slight rise in revs, then it falls back to just under a normal idle. This is normal for my tune.

I'm still on the standard curve, but Ive hooked up the vacuum advance now. Havent noticed much difference, but then I've only done about 30miles with it connected.

[Derek UK]

Although you say that your timing light might be dodgy, it would interesting/useful to know what numbers the strobe shows when the 123 is positioned for what you think are idle and max advance. I note that you said you set the 123 to 0º initially and it started OK. What is it at now?

[asneddon]

I did a little experiment in the weekend.

First, background on why Im not confident in my timing torch. Its a cheap one from Helfords (cant remember the price, but under 100), and it has a dial on the back so you can adjust the strobe. In theory this makes life easier as I just put a dab of whiteout on the TDC mark on the front pulley, then I adjust the dial on the torch so that the timing mark on the cam cover is pointing at this TDC mark. I can then read off the dial what the timing is. Well, the feel of this dial just doesnt fill me with confidence. You can wind it way past zero backwards, and there are no notches or anything to give me the feeling its a digital dial rather than an analoge one.

So this weekend I did two things.
Built a 'step' curve (ie, right angle jumps, not curved) for the 123. so 0d at 0 to 1000rpm, then 10 to 1500, then 20 to 2000, 25 to 2500rpm. No vacuume for anything

I then used my torch and reved the car and adjusted the dial to make sure it jumped in the steps I expected. This actually worked really well, and I got the 10, 10, 5 degree jumps I expected.

Next was to make sure the zero was correct. This is set by having the engine at TDC on number 1 and disconnecting the neg from the coil. You just turn the 123 clockwise until a little LED just comes on. Pretty easy.

Since my normal curve has 10degrees at idle, that means the total idle advance should be 10 degrees. Both my torch and a borrowed one (VERY old and dodgy looking) agreed within 2 degrees. I then loaded a curve with 5degees at idle, and tested again. Same thing.

so, timing is where I expect it to be, and I can probably trust my torch now.

I have put new plugs in, and replaced all the HT leads (with fancy spiral core 8mm ones). I'll check them again next time I get a chance and see if its fixed itself.

What does the colouration of my spark plugs mean though? Its like its running a little rich at the base of the plug, and a bit lean at the top. Is this to do with the heat range of the plugs? I'm using NGK BP6HS plugs with gap at .028

I've been reading this:
http://www.4secondsflat.com/Spark_plug_reading.html
and it seems to suggest I'm not far off, I've jsut never seen the distinct colour change up the earth leg before.