the 24 tooth is crank teeth? or cam teeth?
the later S2k's 2.2L uses a 12.5 tooth crank:
and a 4.5 tooth cam:
grind off the .5 tooth on the crank wheel:
to make it into a 12x crank wheel. you'll likely have to use a voltmeter or pair of LED's to determine the polarity of the sensor (i'm assuming it's a VR/mag sensor). voltage should go negative, THEN positive. same for the cam sensor.
then you need to mod the cam wheel. it needs a single tooth, halfway between TDC of cylinder #3 and cylinder #4. you could have a custom wheel made, or grind off all but one of those teeth and make a new slot so that the wheel can be rotated to a different orientation on the camshaft.
the above is enough crank/cam info for the engine to run.it doesn't NEED the TDC signal to run, it just uses it for fast startup during cranking and to detect TDC when crank acceleration is abnormal. we'll address the TDC in a minute. now, you just need a means of distributing the spark.
enter the GM DIS module. this thing is basically an electronic distributor. it requires a crank trigger wheel with 7 notches (you can cut the notches in the crank pulley, or order up a 36-1 wheel from DIYautotune.com and remove the necessary teeth). 6 of the notches are evenly spaced. there is a 7th notch that syncs the module to the crank cycle. this notch is oriented 70* after TDC. so one notch will line up with TDC, then 60* later another evenly spaced notch, then 10* later, the sync notch.
you'll have to find a way to mount the VR sensor, but it's a fairly simple setup to implement. the VR sensor connects to the module, and from that, the module determines which cylinder pair is on compression/exhaust.
connect the shielded VR sensor wires to the ICM.
connect the 2 pin connector (pink and black wires) to respective power/ground
connect the tan/black wire bypass) to sensor 5V. if this pin is held to ground, the ICM fixes timing to 10* and ignores the ECU's spark timing input.
connect the black/red wire to ECU ground. this should be a common ground between the pair.
connect the white wire (EST) to the side of R81 in your P06/P28 that faces the ECU connector. use a 1k pullup resistor from pin A21 of the ECU connector to 12v to keep it from throwing an ICM code.
connect the purple/white wire (REF) through a 5k resistor to the base of a 2N2222 transistor. connect the emitter of that transistor to ground, and connect the collector to either pin 8 of HIC1, or pin 3 of IC10 in the P28.
the ICM outputs a 5v square wave with the falling edge corresponding with each cylinder's TDC. we needed to invert this (the transistor) and connect it to IC10, which is a schmitt trigger inverter that feeds the signal to the main processor. HIC1 has an on-board pullup resistor. the 2N2222 will pull that low when the REF signal goes high.
the GM ICM takes care of both distributing the signal in a wasted spark configuration and it also controls coil dwell. the white wire is the spark timing wire (0-5v square wave, falling edge trigger). we connect this to R81 because that is the non-inverted timing signal from IC7. Q38 inverts this signal to the honda igniter (0-12V rising edge trigger), so we're bypassing it and getting the signal straight from the processor.
there is also a tach output, but i don't know if it's a square wave or an impulse output. it's the white wire on pin C of the ICM connector. (the EST white wire is on pin B).
that will get the engine running.
there are likely other things that would need tweaking, such as the idle control method. but those are second-order importance. if the F20 uses a rotary solenoid for idle control (3-wire like OBD2 civics), it's very easy to set up, though you'll need to install a FITV from an OBD1 car.
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Topic: Running F20C with an OBD1 Ecu (Read 13926 times)