Crank Sensor

Hi All, My Sisters car (Peugeot 206) only has a Crank position sensor, no cam sensor. Out of interest how does the ECM know if it's on a firing stroke or a Exhaust stroke?

Thank you

Mike

It dosen't have to know, only required with fully sequential fully efi.

It has multi point fuel injection, so it would still need to know when to inject the fuel?

It is a Waste Spark system so the coil doesn't need to know.

WhitwellMike wrote: It has multi point fuel injection, so it would still need to know when to inject the fuel?

I was thinking on first start it would guess and listen with the knock sensor.

Multipoint injection dosen't need to be fully sequential, in this case it probably semi-sequential. Semi sequential is the equivalent of a wasted spark ignition 1 & 4 inject together and 2 & 3 inject together . Only advantage of fully sequential is a small reduction in emmisions and a smaller reduction in fuel consumption.

A lot of fully sequential engines will run even if the cam sensor is not working by reverting to semi-sequential bank fired injection, a good example is the Rove K engine, disconnect the cam sensor and it takes a couple of seconds more cranking then starts and runs perfectly no with no fault warning lamp the only if you scan the fault code shows up.

I hadn't come across this before. I could understand it in mono point injection, but injecting behind a closed valve seams strange.

you asked about the crank sensor and timing...

the reluctor attached to the crank is designed and timed for that. the sensor, either 2 wire, power and ground or 3 wire (hall-effect) power, ground and signal provides the data to the PCM which it uses to set ignition and fuel timing. no cam sensor is needed as the crank sensor does it all.