Honda Repair: 1987 CRX HF 1.5, coolant temperature, temp gauge

Question
Bill,

I have a problem with my 1987 CRX HF (Carb'd). When I start it cold it runs good for a few seconds and promptly stalls. Seems like the vaccumn operated high idle switch is pulling the idle down prematurely. Other times it will idle at 2000 rpm plus for a long time then shut down. The ECU is saying that it is the coolant sensor or open circuit for the coolant sensor (Code 6). The temp gauge on the dash works fine. When the car warms up, it runs fine. Any suggestions? Thanks.

Answer
Don:
You need to check the coolant temperature sending unit located in the under side of the intake manifold. Test the circuit by grounding the sending unit wire while the ignition is on (not started), if the gauge goes deflects full scale, replace the sending unit. My guess is that the sending unit is bad.
Good luck.
Bill