Hello, i have some high idle problem, when warm my engine still runs at 850-900rpm. (What the ultragauge show)
I have cleaned the MAF, IAC and TB, but it didnt change anything, and i think i actually have noticed some MPG loss on my ultragauge since. And i have no check engine.

What should i look at?

I have a ranger 4.0L OHV 2000.

Thanks

 

If you have not fixed this yet, take a look at your thermostat, if it is sticking open, it will try and compensate by keeping the rpm up. and since you have an ultraguage, check your engine temp, this is how I discovered mine was sticking, my scanguage showed my engine only getting up to about 150 degrees and my rpm was right around 850-900 warm also.

 

My engine temps is more around 200-220F, so i think the thermostat is OK.