Thanks Mike,

What got me thinking along these lines was some info I read in a Bosch Manual on 'Continuous Injection - Theory' where it discusses the workings of KE3-Jetronic systems (what's in my car I think) and KE-Motronic systems.

It talks about a thing called Adaptive Control but does state that this only applies to KE-Motronic systems - on reading the text though I began wondering if such Adaptive Control was not part of my car's system, as a fault in this area would almost definitely lead to my symptoms. The text says the following:

"Adaptive control means that the control unit ‘learns’ to make automatic mixture adjustment. The control-unit circuitry senses nominal warm-engine cruise values. It stores those values as the normal open-loop operation, and then uses those values as a basis for both closed-loop and open-loop actuator current. The control unit continually ‘relearns’ the compensations necessary for changes in engine condition, or even intake air leaks.

The air-fuel ratio values are stored in the control unit’s volatile memory, so they are lost any time the battery is disconnected. If the engine runs differently after a service, even if that service was as seemingly unrelated as the installation of a radio or theft alarm, be ready to drive the car normally for about 10 minutes to re-store the nominal air-fuel mixture values in the volatile memory of the KE-Motronic control unit".

Therefore if Adaptive Control was being used in my car (even though the Manual doesn’t mention it as part of the KE3-Jetronic system), and there is a fault somewhere between my battery and the control unit’s volatile memory (that only shows itself after ‘x’ days of inactivity), I’d feel I might be getting somewhere towards nailing my problem.

Any Bosch ‘Continuous Injection’ gurus out there?

Regards,
Neil