motor position sensor

[Alan]

G'day,

I have a HG galant, that has misfires or hesitates under load, normally between 2000 and 3000 rpm.

I checked for stored error codes on the ECU, and found a code 15, which I think is the 'motor position sensor'. I had to use information I found for the eclipse, as I could not find anything about HG Galant error codes.

As anyone else had a similar problem before?

I am not sure if the code reflects the underlying problem, or if it is just generated because the engine is hesitating at the time, and the sensor is returning dud data.

I believe the motor position sensor is in the distributor? I have noticed that my distributor is missing the 'packing' (part 2 on the distributor diagram), is this missing packing likely to cause problems?

Cheers,
Alan.

[Alan]

I did a bit more digging, and realised the page I used to look up the fault code had shortened the name.

It is actually a 'Idle speed control (ISC) motor position sensor fault.'

Is this likely to cause the problem I have had?

Cheers,
Alan.

[A112H]

The short answer is no. I don't know what the codes on a HG mean but I do know what a ISC does. Basicly the ISC is there to compensate for increased load on the engine whilst idling. Like if your A/C kicks in or you turn full lock on your power steering. When this happens you will here/feel the revs drop down and then recover to a standard idle, the ISC does this. I would think the problem is not registering a fault code but is causing issues with the ISC and that is causing the fault, not the ISC itself.
Sorry I couldn't answer your problem, but at least we know what it isn't.

[Alan]

Thanks for your help, Galant_GTO. I am glad that it is not the ISC.

I have had issues in the past with crud in the fuel tank, which damaged the original fuel pump. I had the tank flushed, and the injectors cleaned, as well as had a new fuel filter fitted. The fuel pump was also replaced.

I am guessing that the problem is still fuel related, I might try changing the fuel filter again, as I guess it is possible that some left over stuff has blocked the new filter.

The other possibility is the missing packing under the distributor, which I should be able to fashion quite cheaply out of gasket paper, although I think it will be a fiddly task.

I have tried all of the obvious things, EGR valve, replaced spark plugs and leads, replaced ignition coil etc. I also replaced the throttle position sensor, which was faulty. The TPS is now in spec, and my mechanic has since tested it again for me.

Cheers,
Alan.