Starting issues

[Trebble1999 0]

Wondering if anyone can help.

Been restoring my 1987 pug 205 1.9gti jetronic.. car will not start but when I unplugged the coolant temp sensor it starts up and runs at about 100revs and when warmed up runs about 800 revs and can run for as long as I want, once I stop the car I can not start it back up unless I plug coolant temp sensor back in start it and remove sensor with in seconds or it will cut out again... I have replaced coolant sensor, ecu and airflow meter has been fully reconditioned. Any thoughts?

[welshpug 1,661]

did you replace the blue sensor like for like with an oem Bosch item?

[DamirGTI 342]

Possibly mixed up CTS and SAD wiring plug ..

 

They're both 2pin connectors and could be easily mixed up (especially if any of the connectors have been replaced thus it's not OE color anymore .. CTS should be blue connector , SAD heater black as per OE when new) .

 

CTS wiring/connector is direct to the ECU input

SAD wiring/connector is switched +12V (or near battery voltage) supply to the SAD heater element

 

D