Cis

[JhwShark]

I thought this link might be helpful for those with CIS. Good technical information.
Jon

Auto-Solve Diagnostic Assistance

[DPW928]

This appears to be a good source except for the definition/explanation for the warm up regulator.

"15.1.10 The Warm-up-Regulator
This simple device is responsible for controlling the amount of fuel delivered to the engine during it's warm-up period. The pressure acting upon the top of the control plunger varies depending on the engine temperature and provides an effective method of enrichment."

The first sentence leads some readers to believe it only functions during warm up which is incorrect. The official name of the WUR is "control pressure regulator" which performs a vital function in both cold and warm operations. A better definition is that the wur/control pressure regulator is a devise that provides counter pressure to the system pressure in the fuel distributor. During cold operations, control pressure is reduced to allow a richer mixture. As the engine temperature rises, the control pressure is increased to lean the mixture.

This isn't the first article I've seen with this omission.

Off my soap box now.

[SolReaver]

Thanks JHWShark, A good overview of the CIS system, With a little input as to model specific troubleshooting, diagnostics and component testing procedures this could be very useful to OB 928 owners as well as 924 owners.

DPW928: Excellent clarification, WUR is indeed used in regulating throughout the operational temperature ranges of the system. Your attention to accuracy is noted and appreciated. I suspect the nomenclature Warm Up Regulator was a "best fit" Acronym for the original German acronym for the component. The original (imperfect) description / translation has been duplicated and repeated with little regard for, and / or knowledge of the component. Jump on that soap box any old time.