Quote:
Originally Posted by Dave Colangelo
Could be the crank sensor. You can check the internal resistance on the sensor with a multi-meter (1K Ohms maybe(?) dont quote me on that reading).
What do you mean swapped the "computer chip", the fuel map/tune chip?
I had a 924S which had the same Bosch Motronic ignition system (same ECU basically) that had the transistor on the low side of the coil go and lead to a no spark situation. you wont see this as a burnt component or anything it was just a dead transistor. Electrical components do have a cycle limit and don't last forever. You will need an oscilloscope to diagnose correctly but if memory serves you should always have +12V on the (+) side of the coil and the pulse signal will be from the (-) side allowing it to ground basically. A scope should allow you to see the square wave when cranking to see if the ECU is pulsing the coil correctly. I had the ECU rebuilt by an outfit in Florida at the time (not sure if they are still around). If you have a buddy with a similar car, swap ECU's and test.
Im older and wiser now and could likely desolder the part and match it with some equivalent from digikey but thats not for everyone. The ECU is fairly easy to open up and the boards are 80s style through hole so easy to repair if need be.
Make sure all your grounding points are corrosion free and providing good continuity. Can be a common electrical issue on these cars that causes intermittent problems, loss nuts on the screws can also cause shaky connections.
Regards
Dave |
Yes, the chip in the ECU. The one everyone swaps for a Steve Wong Chip.
Already checked the main ground- body to trans.