According to the Haynes manual I potentially have a faulty Idle Mixer Adjustment sensor? Yet, I cannot find any talk of this sensor nor any parts/prices. I replaced the primary O2 sensor but symptoms didn't change.

Symptoms:

Even with a new battery the car has a hard time starting when it gets say -10 degrees celsius. Cold front moving in and I suspect it won't start as it is going to be frigid cold. No block heater installed either

Also, during warm up, idle stays at 2k rpm until it is warm then it gradually goes down after about 2 mins...is that a normal idle?

If put in neutral during warm up the idle bounces up and down several times. (sometimes)

I can be driving along steadily and at some point as soon as I take my foot of the gas, the CEL will come on...code 11. On a few occasions I tried to accelerate, no response, took my foot off the gas...reapplied and acceleration was normal, no repeat until another day. Hasn't happened in about a week+. The car accelerates very well on average though.

The other oddity I have noticed for 2+ years is the car doesn't seem to shift properly, it will (hit and miss) hang at around 3k rpm but if I take my foot off the gas a bit it will change gear. No CEL has ever come on for that to indicate a possible speed sensor issue? Transmission fluid is fine, the car doesn't burn any fluids, it's fantastic.

Otherwise car runs well...22 year old stove was likely built better than new Hondas!

 

Are you sure it was 11. I guess i should ask where you live, but code 11 is very rare. What your symptoms sound like to me is a intake air temperature sensor. And idling upwards of 1500/2000 is normal in really cold conditions.

 

Thanks Dio, I live in Alberta, lived in both Calgary and Edmonton.

I was surprised about the code 11 as well. I never see it on lists of known codes.

So the intake air temperature would prompt these symptoms even during summer? The car has run the same way in hot or cold conditions.

I don't want to replace anything I don't have to.

 

Most likely not. You can test the sensor with a multi-meter. Not sure what it should read but im sure someone knows. Or the haynes manual might say.

 

Multi-meter, hey? Ok, thanks. Hope I don't have to get a dealership to test it, just saying hello to them costs money!

Certainly not complaining whatever it turns out to be, can't expect more from an aging car and yet the engine and tranny are in great shape.

 

It's probably just an intermittent open in the wiring to the intake air sensor circuit.

When the car is fully warmed up and the intake manifold is hot it should read 200-400 ohms between the sensor terminals.