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noob...considering megasquirt
Posted: Tue Jan 19, 2010 6:07 pm
by Locry
greetings,
noob here, i'm a diesel guy so please bear with me.
i have an 95 s280 engine that i want to convert to megasquirt, reason being the car was recently submerged and replacement modules are too dang expensive. i'm looking for alternative means of controlling fuel/ignition... i'm considering changing out the engine for a diesel, that's the easiest route i think... but why waste a perfectly good engine eh?
i have never worked with a computer controlled efi engine before, i have worked on carbed chevy small-block v8s though... so i know my way around engines however limited that may be
anyway... my main question is this, will mercedes sensors and efi stuff work with megasquirt/megajolt? can i use the oem sensors/coils/injectors etc? i think it will be cheaper to go this route. if its POSSIBLE... i'll do further research... any help will be most welcome!!!
thanks guys!
Re: noob...considering megasquirt
Posted: Wed Jan 20, 2010 5:11 am
by Locry
btw... the engine is a 2.8L M104... 6 cylinder 24 valve
Re: noob...considering megasquirt
Posted: Wed Jan 20, 2010 5:49 am
by Matt Cramer
I'm not quite as familiar with Mercedes as I am with BMW. But a lot of German cars use a 60-2 crank trigger. If you have one of these, it would work well with MegaSquirt, but not the MegaJolt. (While inspired by the MegaSquirt, the MegaJolt is a separate project altogether, and best asked about on its own support forums.)
Does this engine have a distributor? Or is it a coil pack or coil on plug ignition?
Also, does it have a drive by wire throttle? Mercedes seems to have been one of the early adapters here - they actually went to drive by wire throttle before going to EFI on some of their cars.
Re: noob...considering megasquirt
Posted: Wed Jan 20, 2010 6:17 pm
by Locry
AFAIK, it has coil packs, and someone mentioned that it has a distributor on the end of the exhaust cam... (cam position sensor?) is this adequate?
and it most probably is a drive by wire deal... how that works i still have no idea, does this mean the throttle is wired directly to a TPS? the car is a 95 S280, i'm guessing it has almost the same systems as BMW, not sure about the idle circuit tho...
seriously considering going this route...

Re: noob...considering megasquirt
Posted: Wed Jan 20, 2010 8:03 pm
by Locry
quick update:
http://www.peachparts.com/shopforum/sho ... p?t=211918
this link identifies the engine/components of what i'll be working on... hope this'll help you guys make a recommendation.
here's my actual engine...

Re: noob...considering megasquirt
Posted: Thu Jan 21, 2010 9:15 am
by Matt Cramer
You'll need to figure out the trigger arrangement on the crank wheel in order to make it run. Does it have just one coil wired to a distributor, or several coils?
A drive by wire setup would have a computer controlled throttle. With the stock electronics dead, you'd have to swap out the throttle body for a cable operated unit.
Re: noob...considering megasquirt
Posted: Tue Jan 26, 2010 6:26 am
by Locry
it has 3 coils,
i was told the ignition gets its signal from the crank sensor which has an AC voltage (sine wave)... MS requires a square wave?
ok, so with this setup, what kit should i be ordering?
package #1: assume i'll be using the stock sensors etc... just replacing the ECU
package #2: replace everything except maybe the injectors...
package #3: how would you do it if it were you, with simplicity and ease of maintenance/cost down the road.
Re: noob...considering megasquirt
Posted: Tue Jan 26, 2010 6:50 am
by Matt Cramer
You'll also need to know the tooth pattern of the crank wheel. Is it three equally spaced teeth, or a 60-2 (would be 60 teeth, but has two missing)?
V3.0 and later boards can work with a sine wave signal using the VR conditioner.
Also, what were you planning to do about the throttle?
Re: noob...considering megasquirt
Posted: Tue Jan 26, 2010 7:12 pm
by Locry
it only has 3 teeth, so resolution will suck.
i do not know yet what to do with the throttle, but i imagine it would just be an easy retrofit... what would be easiest to work with MS?
Re: noob...considering megasquirt
Posted: Wed Jan 27, 2010 6:18 am
by Matt Cramer
You'll also need a 1 tooth cam sensor - is your cam sensor a Hall effect or VR type one?