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Mass Airflow Meter

ORIGINAL: Diver944

Lot's of people have talked about fitting a MS and it is always billed as being really easy. To date I have yet to hear of one on a 944 in the UK so I hope Simon's is the first success story.
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Yes, the more you look the less real information there actually is. In theory it is quite straightforward, but in practice, virtually all of the conversions (on vehicles that used similar OEM management) are on six cylinder BMWs and they're all just different enough, to be of no real help.

I am confident that its quite easy to replace the OEM crank pick-up with a crank pulley mounted 30 or 60-odd toothed part, but finding out how to run the MS on the OEM Bosch sensors is the problem. At this rate I might actually be the first person to install a plug-compatible MegaSquirt on a 944, using the original timing wheel and sensors.....
 
To run my Autronic I had to give it speed and reference triggers it understood, an inlet temp sensor and a 0-5v throttle position switch. None of the original stuff was any use and I suspect you'll find the same. You might be able to use the original injectors (I didn't want to for other reasons), but like the TPS the 944 uses "non-standard" parts. You'll get it to trigger the original ignition if you really want to keep it. Aside from that it's incidental stuff like wiring the fuel pump relay to power the pump at the right time.

I can't see it will be any easier unless you can get it to run with the Porsche triggers, but every EMS I have looked at in any detail needs a camshaft sensor which you don't have.
 
In theory, which I seem to be saying a lot at the moment, you can use the OEM TPS and all that you need to add is an inlet temperature sensor (on pins 29 / 30, as theyre unused...). In practice, people seem to be adding crank pulley mounted trigger wheels, for EDIS wasted spark systems and all sorts.
 
The TPS was easy. I had a 306 GTI-6 engine with a run big end in the corner of the garage so I whipped one off that and my indie's father in law machined a round adapter in perspex using (I assume) a wood lathe, which we used to mount it. I bought a few Bosch connectors from the local agent and used one of them to connect the wiring to it.
 
Megasquirt will work with one 36-1 trigger wheel and you can go without TPS if you use a MAP sensor although it is compatible with the turbo TPS, (I bench tested it} the lux only has limit switches for WOT and idle.
 
It works out required fuel using manifold pressure readings and witchcraft in the software, prob better to have TPS but not vital

 
Sounds like a recipe for a mapping nightmare. It's hard enough to set up from scratch when you can teach the EMS your throttle position by sensor voltage so it knows demand, and utterly pointless extrapolating something it's s easy to measure directly.
 
ORIGINAL: Fen

Sounds like a recipe for a mapping nightmare. It's hard enough to set up from scratch when you can teach the EMS your throttle position by sensor voltage so it knows demand, and utterly pointless extrapolating something it's s easy to measure directly.
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I agree, just pointing out it is possible
 
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