So, when stopped and idling, my car will shudder on occasion. I have a feeling it's more related to the ac compressor, but I had the thought and wondered if it was misfiring... so, what's it like if your car is misfiring?

 

It's like coughing , car wobbles when idles , shaky as well

 

Generally 'lumpy', although the more cylinders there are, the more masked it can be.

I generally pull one plug lead at a time, to see if there is a difference from one cylinder.

Mind you keep your hands on the insulation and do not otherwise touch the car, otherwise you'll end up with Bart Simpson's hair style.

 

Richard, NO plug leads on an X300 AJ16.

If it sort of stumbles as the a/c comp goes on and off, it MAY be the "idle control unit" that is gummed up and sticking, so cannot keep up with demand fluctuations.

Your market has exhaust gas recirculation stuff, and we dont, and I have read here on many occassions that this EGR system gets all gummed up and reeks havoc with idle control ????.

 

My bad, didn't notice year.

Thanks Grant.

 

So, where is the idle control unit? I'd love to give that a look since there is one of those, and 6 cylinders to check. That, and I'm a bit low on tools being at college. I haven't got a good extension for my spanners to take the spark plugs out. Of course, I'd have to get that and a gap setter (or whatever it's called) for the plugs.

 

So, how about that idle control unit?

 

Idle control unit is on top the throttle body to the side of it below the throttle linkage. Be very carefull when removing the idle control valve because the two little bolts just love to break off inside the thottle body. I can add a picture and instructions how to replace if you would like.

 

Yeah, if you could post a nice picture, that'd be great. I had a look at it, and it seems near impossible to undo the second bolt without removing something else. Is this a big job? because it seems pretty simple.