I've noticed an anomally. When driving in closed loop, if I depress the clutch switch the ECU goes out of closed loop. Let off the switch and the ECU goes back into closed loop.

This happens on my 86 non turbo car. It does not happen on the 87 turbo cars.

Anybody have any insight into why the 86 kicks out of closed loop if the clutch switch is depressed? For a little clarity, the pedal does not have to be depressed far enough to disengage the clutch, just resting the foot on the pedal enough to *make* the switch, kicks the ECU out of closed loop.

NOT desireable for emissions testing, where the operator PROBABLY rests his foot on the clutch pedal just in case the car comes off the rollers. No closed loop MIGHT cause the car to not pass emissions testing.

 

i think that's an ecu programming thing. You could just tape the switch closed for the test and then remove once done.

ECU will just think the clutch is engaged all the time.

 

load no load condition? Maybe mazda engineers made a correction in 87 to reduce emissions

 

Load and non load. Once upon a time I had a way of seeing if my ECU was going into closed loop, and could do this sitting in the driveway. . With a LED connected to the two middle sockets of the green, six socket check connector, and the TPS disconnected, you push the clutch and put the transmission in gear. Then slowly rev to 1700 rpm and above that figure.

Around 1700, the LED will/should start flashing, showing that the ECU has gone into closed loop. This procedure is in the 1987 FSM but meant for a Mazda Monitor, and the difference is they have you disconnect the neutral switch, then the TPS and watch the Mazda Monitor while reving to 1700 rpms.

I've done this in the past, and I'd swear I've done it on this 86 non turbo. LIke I might have said, it still works on my 87 turbo's. And the 87 tubos can be driven in closed loop and the clutch pedal SWITCH depressed and they stay in closed loop.

I agree. I just need to depin the clutch switch at the ECU (it's working right by the way, inputs 12vdc when the pedal is pushed down) and just go do the emissions test. And I suppose if I really wanted to know, I'd chunk the RTEK in the bin and install a stock ECU and see if that one goes out of closed loop while driving and the clutch SWITCH (not pedal) is depressed. I've a lazy streak.