Here is a new problem, my temp gauge goes completely to zero imediately ever time and for as long as my engine goes over 6,000 rpm. No other guages affected. Its not engine load related accelerating or decellerating. and its only the temp guage. this is bugging the hell out of me, has anyone ever experienced this. It just started a few days ago. Car runs perfect outside of this. I have the LX cluster in a 1989 Civic DX hatchback. With a ZC enginge and tranny, with the JDM ZC ECU. My own custom made wiring harness. It does the=is steady state driving, accelerating or decelerating. slowly build rpms at 6,000 abd bang all at once the guage drops, or accelerating it doesn't matter. Anyone have ideas? I'm stumped.

 

check grounds

 

or temp guage sensor connector on head is lose/not connected properly.

every time i shifted the temp guage would go down. re crimped connector. put back on. problem solved

 

my friends b16 was like that
whenever he rev'd it out, poof temp gadge just went to zero
kinda funny actually, never caused any problems tho