DaveK

Hi,
Since I have occasional hesitation / idle hunting I decided to check out some of the sensors on the car. However, when I tried to check the idle microswitch at the DME connector, I could not get a reading.

I used Adrians book and checked pins 52 & 24 as per page 390. However - I got open circuit even with the switch closed.

I tried the connector close to the idle switch - and this gave the correct values so the switch itself is OK.

Are the pinouts in the table correct? If so, I guess I have a wiring fault or wasn't touching the connector correctly with the probes. I measured the air temp and engine temp readings at the connector OK though so I think the probes were touching the connectors fine.

Lorenfb

The book is correct, pins 52 & 24.

warmfuzzies

Is it possible that another circuit is influenced by this? What I mean is unless the circuit to be measured is isolated, or if you know what other circuits are around, so that parallel equations can be done...you may be getting weird readings?

Kevin

DaveK

I would expect this circuit to be fairly stand-alone. The funny thing is - my idle hunting is occasional and only when the car is hesitating at constant speed (and it's not that bad anyway) so I suspect the DME does see the signal and it was probably my error.

I'm going to take another look at it at some point - and make up a test lead which makes it a bit easier to check the DME connections. I'm also going to try unplugging the idle microswitch and seeing whether that makes a noticeable difference to the idle - since that would prove the connection is OK really.

Lorenfb

Once you unplug the DME unit, there's nothing else on the idle switch circuit.