so long story short, a customer came with a 96 prelude vtec to tune his s300
the car has a hondata obd2a to obd1 hondata jumper harness, and being this particular year/model the distributor only has 1 cylinder position signal and the 2 others are delivered via the crankshaft sensor..instead of all 3 being in the distributor.
the car was fully built by another shop, top and bottom the whole nine yards but needed a tune since we're hondata dealers and one of very few in the south east with a dual eddy steady state mustang 1750 dyno (you can run the 1/4mile on it and everything it's pretty sweet).
the car was throwing a code 4 in the hondata aka crank position sensor malfunction. we hooked up the stock obd2a prelude ecu to see if the problem was the hondata'd p28 ecu. car throws a p0335 crankshaft position sensor A circuit malfunction.
we check the wiring, there is continuity from the sensor to the corresponding ecu pins so that's not it.
i do the ohm tests on the sensor, the fsm says 500-1000 ohms, any different and replace the sensor. the sensor ended up testing ~2000 ohms and the other 2 pins had 2120 ohms of resistance....a little high but i'm not ready to condemn this sensor yet...considering the car will start plugged in, but will not start with it unplugged....
long story short, we speak with the customer and come to find out the car has a balance shaft removal kit on it...not finding a problem anywhere else we remove the pulley and lower timing cover and see the issue.
this balance shaft removal kit uses a key'd disc to take the place of the balance shaft pulley on the crankshaft...which is fine for a car with all 3 sensors in the distributor....but for this 96 prelude this is not kosher, since the ckpp sensor uses the balance shaft pulley as a reference for cylinder position.
bottom line is, these kits work fine.....but when the car needs the OE balance shaft pulley there to run properly...don't use the aluminum balance shaft spacer in it's place or you will have this issue.
the symptoms are won't rev passed 3-4k
check engine light (if working)
once the code was set the timing was staying fixed even upon acceleration (which it should advance if working properly regardless of the other stuff)
anyways, hope that helps someone else out.
Dave @ Lethal Injection Motorsports
205A Tidwell Drive
Alpharetta, GA 30004
770-343-9969
