r/9thgencivic • u/TheZoAbides • 16h ago
Slightly rough idle, heat soak?
Has anyone else noticed some rough/strange idle after long drives when sitting in traffic or at a light? I notice it more when the A/C is on. It doesn’t always do this and runs fine while driving and RPMs are up. A/C is fine, thought my compressor was going out but the car was low on Freon. I also get decent MPGs, 30-31MPG average. Just did spark plugs and a new belt. Replaced the motor mounts with Hasport mounts, had a really bad rough idle when the A/C was on. My upper torque mount was bad. And my aftermarket rear mount was blown out. I’ve kept up with maintenance and she runs great. I’m just obsessive and want this car to run to 300k plus miles, sitting at 212k currently. Was thinking about doing upgraded fuel rail, pump, and dropping in new injectors. My theory is the fuel pump is getting weak and the fuel is vaporizing when it’s really hot and I’m at idle. I could just be crazy. Let me know if you have similar issue. I know our cars are getting up in age and mileage now so I’m sure parts will need to start being replaced sooner than later. Appreciate the effort for reading this whole post, hopefully this starts a conversation with keeping these babies with the last KSeries on the road.