I'm having an pain in the ass issue with a 316i m40b16 engine
If I apply any engine load on the car, it cuts power on what it looks like it's an ignition issue. The rev counter drops to zero and then goes back to normal.
I changed all the ignition system last year. Plugs, ht leads, dizzy rotor, dizzy cover and ignition coil.
Also last year I changed the CPS and the ECT sensors.
All new stuff.
This behavior of the rpms suddenly dropping on the tach below on what should be reading when the cut happens, gives way the CPS sensor, harness or ECU.
Last year I put a brand new CPS from Valeo and fixed another issue that I was having at the time.
Assuming that the E30 are known to Eat CPS sensors, I bought a new one from Vemo but when I tried on the car the issue remains.
I check both resistence from both CPS and they are at 560ohms. I also checked conected to the harness and pin 48 to 47 from the ecu plug and got the same results. So this eliminates the harness I guess.
I open the ecu looking for shorts, first test was pin 47 to pin 2 (ground) got resistence. But pin 48 to ground got 3.3ohms. I don't know if this is by design, I've tested all the caps and resistors from the ecu and didn't find any short.
The AFM I did a test driving the car and the voltage goes smooth, when the cut happens the AFM is still giving voltage, no suddent drops.
I also tested the one year old ignition coil and got primary of 2.5 ohms and secondary 8k Ohms.
The last thing that comes to my mind is the harmonic balancer, I clean it up and it doesn't seem very rusty.
What do you guys think? It's time for a Standalone Ecu or I am missing something here
