shadowdawn

While I was outside smoking a cigerette and pondering my cause of my CEL codes 71-74 I was wondering... How does the car idle when its getting no air? It needs air and fuel to combust to crank right? Well at idle when the throttle is closed how is the engine running without air?

Stupid question I know, but hey you live and learn.

Also I noticed getting in my car today the CEL was lit up (as usual) first time since restarting it yesterday, suprisingly it wasn't the usual code 13 but started straight off with the misfire codes, but this time only 71 and 72.... not all four like usual.

I know one of the possible causes is "not enough fuel delivery" Which also makes me wonder, is it possible I'm throwing the codes because at idle I'm not getting enough fuel perhaps? Reason I say this is because I don't remember the CEL coming on while driving before I noticed when I started her up.... perhaps while she was idleing and warming up it threw the codes then?

Just a thought...

Also what A/F mixture are you turbo guys running at idle?

inspyral

There's a hole that lets a certain amount of air thru to keep the car idling. When you adjust the idle adjuster screw, it adjusts the amount of air that gets thru with the throttle plate in the closed position. The IACV also lets air bypass the throttle plate and enter the IM. How much air the IACV lets in is regulated according to coolant temp, which is why the tb and IACV have coolant lines running to them. If take off your charge piping and look into the TB, there's a round hole on the firewall side that leads to the IACV, and there's a groove towad the top that you can't see, that's where the idle adjuster screw lets air thru.