MCBladeRun
Club Member
Wouldn't a faulty dizzy cap cause misfire, not retarded firing?
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123 ignition for Datsun L6 on my L28
- Thread starter AliK
- Start date
Farmer42
Club Member
Yes I did. It lost the file with the curves on it when I disconnected the battery. This time it is all there but not running at all right
Hmm.
There didn't look as though anything was wrong with it but I could swap it over along with the rotor arm. I do have spares given the notoriety of the quality of them coming from 123. I'll try that first then remap the timing curve. If that doesn't work I'll swap back to the 280zx.There is a misfire. If the cap is faulty it could cause retarded timing.
I think this will be a job for the weekend. I'll try the things and report back.
Farmer42
Club Member
Had some spare time today so decided to give it a go to get it running. Changed the cap & rotor and reset the mixtures on the carbs. Again took an age to start but eventually fired up and after a couple of minutes started popping again. Took the revs up to around 2500 and it gave one huge pop then ran very erratically but without the popping.
I decided to change the spark plugs and set the gaps to 1.1mm rather than the 1mm for the old ZX dizzy. Bingo! It now runs smoothly on tickover and revs without misfire. The only thing I did notice is that the app showed the timing at 30degrees at 900 rpm when it should have been at 15 according to the point on the timing curve. Checked the timing with the light and it read 30 degrees. Why would the dizzy ignore the curve setting? The static setting was 0 degrees.
I decided to change the spark plugs and set the gaps to 1.1mm rather than the 1mm for the old ZX dizzy. Bingo! It now runs smoothly on tickover and revs without misfire. The only thing I did notice is that the app showed the timing at 30degrees at 900 rpm when it should have been at 15 according to the point on the timing curve. Checked the timing with the light and it read 30 degrees. Why would the dizzy ignore the curve setting? The static setting was 0 degrees.
Vac advance is the only culprit that comes to mind - upload your curves and let’s have a look (would prefer the timing curves rather than a selfie).
In my experience with popping after the car is started it’s nearly always (all other things being equal and untouched) unburnt fuel caused by a bad spark plug or my famously intermittently failing Magnecore 8.2mm leads. Beyond the exhaust blowing up saga, these are the only other times I had popping while on the power.
yellowz
Club Member
That's about right!
Nigel Brook
Well-Known Forum User
Seems to me, stick with a 280zx, plug and play !!Only one thing for it, get a Speeduino
You know, I went there in my head when I first had teething issues with the 123 (at the top of this thread) - now I would never go back to the old distributors!!!
The 123 is a BRILIANT bit of kit once you've got past the initial niggles. No second hand 280zx distributor will ever be as good with a 40+ years worn shaft / wobble or provide the benefits of: accurate timing, super flexibility / customisation, from inside the car tuning, rev limiter, immobiliser etc. It's a shame they can't supply a decent cap from the off and more quickly address some of the niggles. On the plus side, I've found the support and app feedback very good / quick in addressing any issues.
The 280zx dizzy has now been permanently consigned to the spare wheel well, in case of any emergencies or if I need to rescue a fellow Z car owner on the side of the road!
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Farmer42
Club Member
I agree with not going back really. There was a reason that I changed dizzys and it was because of timing problems caused by wear. I started it up again today and it ran fine even when I increased the revs. It seems as though it was the spark plugs even though the previous lot was less than 500 miles old. They don't seem to like sooting up even if you clean them. They must overheat so that it why I have increased the gaps. Should be a stronger spark and burn better. Im not going to do many miles over the winter but will keep an eye on things.You know, I went there in my head when I first had teething issues with the 123 (at the top of this thread) - now I would never go back to the old distributors!!!
The 123 is a BRILIANT bit of kit once you've got past the initial niggles. No second hand 280zx distributor will ever be as good with a 40+ years worn shaft / wobble or provide the benefits of: accurate timing, super flexibility / customisation, from inside the car tuning, rev limiter, immobiliser etc. It's a shame they can't supply a decent cap from the off and more quickly address some of the niggles. On the plus side, I've found the support and app feedback very good / quick in addressing any issues.
The 280zx dizzy has now been permanently consigned to the spare wheel well, in case of any emergencies or if I need to rescue a fellow Z car owner on the side of the road!
Robotsan
Club Member
Has anyone taken the risk on any of the Chinese electronic L6 dizzys on eBay? This guy on FB in the US has been selling them for a while and says they've been good, only a couple of failed units out of 100 last sales.
This is his eBay listing: https://www.ebay.com/itm/394684304099?hash=item5be5048ae3:g:UA0AAOSwU8Rk00JS
This is his eBay listing: https://www.ebay.com/itm/394684304099?hash=item5be5048ae3:g:UA0AAOSwU8Rk00JS