1990 240SX fluctuating idle problem

[jerryk]

I own two 1990 240sx. Both are on the road. I have a fluctuating idle problem with one of them with 177K on the engine. It is scheduled to be my final car. I know what the idle is supposed to be a bit above 730 because my other one with 220K has a perfect idle. The fluctuating idle goes between 800 and 950 when warmed up or at a stop. Sometime it fluctuates worse then others but it never goes below 800 and is always moving. I just made a trip to PA and the road mileage is, I swear 31MPG, but in the city, it ranges between 21 and 23, which is costly these days. The other car gets 25MPG in the city and 30MPG on highway. I have both cars at a mechanic and he has been swapping parts.

Air regulatorAICVMAF meterEGR valve

I would appreciate any ideas.

Air regulatorAICVMAF meterEGR valve

I would appreciate any ideas.

[S14-NEO]

might wanna try a tps sensor.

[rogoman]

Here are some possibilities:- sticking EGR valve- bad O2 sensor- major vacuum leak- bad spark plugs

[s13bassboat]

AICV is what i think it is. imports in general are notorious for this. try it out

[M374llic4]

I take it that must stand for air intake control valve? If so, what other valve is in the intake besides the throttle??

Alot of people say "Check your AICV, your ERG, your IAA" or what ever else the acronyms are, I have no idea unfortunately what and where they are, is there any write up or pics, or at least explanation of what and where they are? They just need a basic cleaning?

I am having a idle problem my self on a 95 KA24DE, so I would sure appreciate the help : )

[b_rad]

zerothread/253879