Imobilyser

Discussion on Future Megajolt hardware / software upgrades.

Moderators: JeffC, rdoherty, stieg, brentp

Post Reply
Yvan
Posts: 86
Joined: Fri Feb 08, 2008 7:58 pm
Location: Kragujevac, Serbia

Imobilyser

Post by Yvan »

Just a thought... Cold MJLJ be programed to cut ignition intermittently, to simulate broken engine. So that it can be used for car theft prevention.
'87 BMW 316 E30
1600cc M10B16
petrol + LPG, MJLJ

brentp
Site Admin
Posts: 6274
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Off the top of my head, you could enable a very low rev limit which would effectively make the vehicle un-drivable- especially if a hard rev limiter was part of the system.
Brent Picasso
CEO and Founder, Autosport Labs
Facebook | Twitter

Yvan
Posts: 86
Joined: Fri Feb 08, 2008 7:58 pm
Location: Kragujevac, Serbia

Post by Yvan »

How about a map filled with zeros and a hidden switch?

What happens if you set advance to 0? Will the engine run? I have quite high advance (compared to what I saw at ignition map library here), it goes from 18@1000 rpm up to 42@5500 rpm (that's @ 100 kPa MAP).

Or an configurable option to toggle rev limit value with an external switch?
'87 BMW 316 E30
1600cc M10B16
petrol + LPG, MJLJ

MartinM
Posts: 433
Joined: Sat Aug 27, 2005 12:08 pm

Post by MartinM »

Will it run at 0BTDC - don't know. Why don't you try it?

If you do something clever with the map or rev limit, then the simple way to defeat it is to just disconnect the MJLJ (although that might not be a particularly obvious thing to do I admit!)

Seems all a bit complicated - if you're going to have a hidden switch then you might as well make it:
- control the EDIS power supply
- interrupt the VR sensor signal
- or something similar that stops the engine starting completely, rather than jumping through hoops to make the MJLJ do something

My $0.02....

Yvan
Posts: 86
Joined: Fri Feb 08, 2008 7:58 pm
Location: Kragujevac, Serbia

Post by Yvan »

I know that I can do that. But I wanted something that would simulate bad running, cutting, stalling. I could use reed switch, and just use small magnet on a keychain to activate/deactivate this feature.

And I already do have hidden switch that prevents engine running (I had cut power to some relay, I do not remember which, I did that more than 15 years ago).
'87 BMW 316 E30
1600cc M10B16
petrol + LPG, MJLJ

brentp
Site Admin
Posts: 6274
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

I agree with Martin. A hidden fuel pump switch, for example, is an effective immobilizer. If the engine is fuel injected, it just won't start- otherwise the carb'd engines will run until the fuel is depleted from the bowl. Simple and effective.

Others have talked about a 'valet mode' where the rev limit is enabled at low RPMs. this could give the effect of a bad running engine..


... Or, I could just give you an old, buggy firmware build. :D
Brent Picasso
CEO and Founder, Autosport Labs
Facebook | Twitter

Dimbit
Posts: 39
Joined: Thu Jan 17, 2008 8:25 am
Location: Newbury, UK

Post by Dimbit »

I know a lot of people here in the UK have an MOT map with a 1500rpm limit, so they can't go having any fun with your car while you're not looking. That's very effective. Alternatively cutting power to the coil works well because it'll still crank but not fire, so any would be thief would think it's just too cold or unreliable.

Post Reply