Megajolt quetsion - non-technical

[heraldcoupe]

I'm toying with the idea of going Megajolt on one of my non-Triumphs, specifically a Mk2 Golf GTi. I was hoping to built from a bare PCB, but all I can find available, at least as far as the UK is concerned, is an assembled module or a full kit.

Are PCBs or parts kits available anywhere, or has the world moved on from that option?

Cheers,
Bill.

[GT6boy]

Hi Bill- not stalking you, just logged in by chance!
Not sure- I bought mine pre-built some years ago, save me marmalising a PCB and componants in the build. as you say, the world may have moved on in the ifollowing 10 years.

[Nick Jones]

Bill,

Good question......

20 mins of googling suggests not.  Megajolt E seems to be the new baby and I see no kit version.  Probably because it's all surface mount.

There are alternatives, some of which now work perfectly well without EDIS.  If you want to build it yourself it looks like you are limited to Megasquirt (doesn't matter if you don't want to inject anything).

MS1 ver 2.2 Hardware can still be bought as a kit and when used with the MSnS Extra firmware will control EDIS in the same way as MJL.  This is cheap.

MS 1 ver 3.0 hardware can also still be bought as a kit and can control EDIS.  Add the MS 2 chip and it'll do ignition without the EDIS box (needs a distributor head though).  Add another ignition driver (single component) and it'll do wasted spark without EDIS.

Other things out there (no self build but still 3D programmable)

http://trigger-wheels.com/store/contents/en-uk/d59.html  Megajolt e, still good value.
http://nodiz.co.uk/nodizpro-shop.html - Bit dear
http://www.accuspark.co.uk/Blackbox.htm?gclid=COK81IyeiLsCFZGWtAodSy0AAQ (first time I've seen this and not a great as first appears - limited adjustment points and only 2D - not load sensing.  Full throttle racers only!)

Microsquirt
http://trigger-wheels.com/store/contents/en-uk/d31.html

One other thought.  How old is your GTI?
On earlier K-jet GTIs (up to '86 IIRC) they have a clockwork dizzy (albeit with electronic guts) and I can seem some benefit to changing that out.
However, post '86, the injection went electronic and although they still have a distributor, it only performs basic position sensing and spark distribution duty, with 3D timing control and knock sensing being performed by the engine management ECU.  On these cars the benefits are less clear cut (could even be a downgrade in some respects) unless the engine is modified to the point where ECU settings are no longer good.

Cheers

Nick

[heraldcoupe]

Thanks Nick, I was considering the Megasquirt as a possible alternative if there was no Megajolt kit.

The car is a late 1991 GTi, very simple distributor. This is failing in a similar manner to our old Passat of similar vintage, the trigger from the distributor is very vague, if I can get a scope to it I expect to see a very rounded leading edge to the trigger pulse. Result is the timing moves about all over the place. Easiest, cheapest fix is to stick in a new distributor, or sensor if i can get such a thing as a discrete part. With my son showing an interest in all things techy though, it struck me as a a good opportunity to work on a real-world project with him. He has a reasonable understanding of how ignition systems work, but going through the full 3D mapping with him would provide good educational value,

Cheers,
Bill.

[Nick Jones]

Ok.  But does the existing distributor have mechanical advance in it?  I don't think the later ones do, because the timing is controlled by a map in the ECU (though as you say the actual timing will still be affected by the triggering point).  It is possible that I'm mixing things up with the Mk3 (which has much more advanced management), but if I'm right you'll need to figure out some way of keeping the original ECU informed of engine position.

Of course you could go the whole hog and MS the whole thing using the existing hardware (wiring and tuning job).  Would be really neat if you could lay hands on a spare ECU, gut it and build the MS into the case with the original loom......  With MS 2 ver 3.0 you should be able to control all the existing features (possibly excepting knock sensing).

My eldest is showing interest in electronics at present though not so much as relating to cars....

Cheers

Nick

[heraldcoupe]

I'm reluctant to dive into the injection system, at least for the moment. The car is used as daily transport, progressive mods to introduce an alternative ignition system can largely keep the car working while the work goes on. On the other hand, once the ignition is operational and other cars come out to play next summer, I could have more opportunity to play with the injection system.

Lots of reading I think for now,

Cheers,
Bill.

[James]

Bill,


Sounds like you should start with a Megasquirt running ignition only.

Injection is then a simple step away of plumbing and injector wiring (and a wideband sensor)


James

[heraldcoupe]

jcarruthers wrote:

Sounds like you should start with a Megasquirt running ignition only.

Injection is then a simple step away of plumbing and injector wiring (and a wideband sensor)

Exactly.

Cheers,
Bill..

[Nick Jones]

No plumbing needed - already electronic injection installed.  Wiring can also be minimal if a cunning interface can be made to the original loom.

Nick