99BlackMaxMS

iTrader: (85)

I know this has been brought up in the past many times, but after having no luck with the 5th gen IACV, I had Kevin install the 4th gen one on the car. No real problems other than the first 15 seconds the car is on, I have to feather the gas pedal. He adjusted the TPS a little bit to accommodate, and I think the 5th gen IACV he was using was bad.

I know the 5th gen IACV will work with some minor fabrication, but will that solve my cold start issue or is it expected to have a crappy idle?

Thanks in advance,
Matt

MOHFpro90

iTrader: (11)

Im running 5th gen IACV, with the modded plug. Other than a vacuum leak causing fluctuations in RPM, my idle is fine.

I dont have any cold start issues, but it doesnt get 'cold' here, only low 30s at most.

99BlackMaxMS

iTrader: (85)

I am 99% sure it is because I am using the 4th gen IACV w/ everything else 5th gen. Anyone have an extra laying around?

MOHFpro90

iTrader: (11)

I am going to a junkyard in the next week or so to get a new A33 UIM, you want me to see if they have the IACV too? Should be cheap, as they are charging me half of what the competitors around here are, only $100 for the UIM.

99BlackMaxMS

iTrader: (85)

Most definitely...I put up WTB threads in the 4th and 5th gen classifieds, but if you can get one for me I would really appreciate it. Thanks dude.

MOHFpro90

iTrader: (11)

Ill check for yah.

mowgli29

iTrader: (21)

I'm having same prob with mine, running 4th gen IACV also.
I chose not to use the 5th gen IACV...mostly because it doesn't fit above the vacuum lines.

Our cold start problem makes sense in a way...if you think about it, we removed the wax element, since it was in the 4th gen TB. What is supposed to happen is: the wax element is hard and holds the TB open a tiny bit when cold. Once the wax is heated up (via hot coolant) is melts and the TB returns to its closed position and air used for idling then comes only from the IACV. Since we have no wax element to hold the TB open, we must use our foot as a replacement!

As far as I could tell, the 5th gen TB does not have a wax element...but where the coolant runs thru the 5th gen IACV, there is a piece of coiled aluminum, which I assume, performs the same task.

I'd say the two ways to resolve the cold start issue are to get an adapter fabbed up and use the 4th gen TB, or use the 5th gen IACV. Personally, I'd like to use the 4th gen TB, but getting an adapter fabbed might be too expensive.

I have another idea..I'm pretty darn sure I need a much bigger nipple and hose running to the manifold (from the 4th gen IACV). doesn't matter whether the IACV is turned down, or cranked up, it idles the same. I have to adjust the idle with the throttle body set screw. I'm hoping now that maybe, just maybe, if I get the 4th gen IACV to flow as much air as possible, it might be enough to keep it running on cold start. If not, I'll be needing an adapter to go back to the 4th gen TB.