1983 sc lambda/CIS fused removed for unknown reason
 

I bought this car a year ago , haven't driven much been restoring , anyway was getting a/c working today and dome lights (fuse missing ) and now know this is also lambda fuse too. Basically when fuse is in car runs like crap surges runs rich but in the morning first start run awesome . Have to remove fuse after engine is warm for it to run right. At first it felt like it had more power when the fuse was installed. Any ideas thanks

doc,

It means that the PO, or his hack mechanic, did not have the knowledge, experience or money to fix a running problem with the engine, so they disabled the ECU and bodged the mixture screw to compensate. If you do not know how the lambda CIS system on your car works, read the BOSCH manual online or Probst or Bentley and the "CIS lambda" posts on this website. You will never get near factory drivability without the FV pulsing at the default value. The K basic part of lambda CIS is calibrated way too lean for the engine and the FV pulses bring it into range, then the O2 sensor part of the system is able to trim the mixture around stoich by altering the FV pulse. You can figure out what is going on with an analog dwell meter in a few minutes of testing. One guess would be you have vacuum leaks from the injectors, boots, hoses, cracked airbox and the PO disabled the system and cranked up the mixture with the adjustment screw in an attempt to mask the problem.

Thanks. I figured po hacked it!