Mazda Forum - Mazda Enthusiast Forums - B2200 Intermitent Smoking: HELP PLEASE

I got my 200,000 mile '885sp B2200 running great with one exception. It is all stock except for gutted cats. After the engine warms up, and the high idle comes down it runs great and clear. Then (randomly) after fully warming up and coming back down to idleit is slightly high, and the engine is smoking.I checked the choke flap and it is not sticking, but somehowitis idling 100-300 RPM high intermitently and when it does it is really rich.

Is there some sort of fuel enrichment from a thermo sensor or anything of that nature that could be causing this? I read an earlier post about a temp sensor that can put the truck into a limp mode that would make it run rich. Also the only thing that doesn't work on the truck is the water temp gauge, however I don't think this is related. The engine does come up to temp and maintain just fine.

If anyone has experience with this it would be a great help. I really like the truck, it is much nicer to commute in than my Dodge Cummins 1 ton dually, but I really need to figure out this problem.

Thanks in advance-
Scott