Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing stepper problem? (plus 8 3.9 '93 cux14)

Hi there,

at the moment I am on the track of my sporadic idling problem (plus 8 '93 CUX14). Sometimes the engine runs too fast at the traffic lights. Some days everything is ok.

I checked the electrics of the speed signal (many thanks to Mike (teknome) for sending me a circuit diagram!) Then I built an adapter that allows me to access the engine control unit with rovergauge.

Everything looks good, even the stepper motor can be controlled when it is removed.

I have come to the assumption that a sporadically failing mechanism of the stepper motor could be the cause.

After cleaning the sealing surface and a few drops of WD40 on the mechanics, the first test drive was successful. But how long does it last? I would like to swap the stepper motor.

Now I've read a lot about poor quality spare parts. Has anyone had a good experience with a particular supplier?


Greetings from the Sauerland (Germany)
Günter

sorry for my bad English but school's out for many years

Gunter, I have bought other parts from this firm and they have been as advertised and these prices seem to reflect a quality product.

There are other suppliers from £22 but I wouldn't waste my time with those tbh.

Good luck.

I bought my Stepper Motor, Fuel Injectors and a few other bits from Mark Adams at: www.tornadosystems.com

I had a similar problem on a 1997 +4. The stepper motor rotated a cam which pushed a brass pin which opened the throttle, the pin would stick. After a good clean the problem was solved and didn’t reoccur, but it did take me 3 months to discover this after changing sensors, trying a different ECU ………..