Ok so I have a 420a turboed and when i drive the car cold (meaning before the car completely warms up)...it doesnt idle down properly...it idles down very lower.

Ok when the car warms up it idles down really fast....Ive been trying to figure this out for awhile now with no luck...Ive replaced IAC, TPS, and Ive deleted the egr system which didnt change a thing as far as my idle issue....this has been kickin my @*#!

When you say it "idles down lower, and idles down really fast", are you saying on a cold start your idle is to low, and when its at operating temperature it idles too high?

Typo.....I meant it idles down very slow...sorry....But no it doesnt idle up too high or too low....When it gets to running temp it idles down really quick...This is all happening when i shift by the way.

Hmmmm, what are you using to tune?, do you have a logger or scan tool? If so see what the IAC and TPS are doing between shifts when cold and again when its warmed up. Make sure the tps is set right.

What are the rpm numbers? Too low and really low aren't specific. Also a mod list would help.

Well im not using anything to tune...I have a scan tool at work but no logger...Ive put the scan tool on the ECU and it a EGR code P0403...I deleted the EGR system since then tho although it still throws the code...im running lean btw if that means anything...Also I didnt know you could set the TPS although ive have replaced both the IAC and TPS and nothing changed..

Shake, it really doesnt matter what rpm im at when its cold it just idles down extremely slow when i shift gears but once it warms up it it idles down really quick (faster than it normally should)...But just so there is no confusion the car idles down to the rite rpm it just takes forever to get there...i honestly dont thiink its a vaccum leak but i could be wrong...

Mods list not much : T3/T4 turbo kit, revised lifters, narrowband air/fuel autometer gauge...and im about to install my FMU and wally 255 pump

When you shift in a 5speed it usually drops down 2000 rpms in between shifts and his is either doing that to slow or to fast. You know running lean is really bad right? You can melt your pistons and many other things. You need to tune your car or get bigger injectors before you damage your motor. I'm not sure about your rpm issue mine did that before but it went away.

yea I know im correcting that problem as we speak....IM starting to wonder if my idle issue has something to do with my ECU tho

it also could be your map sensor or egr making the idle not react proper between shifts.

Very ture, but wouldn't that throw a code?

SUpracliPse86 said:

Very ture, but wouldn't that throw a code?

Click to expand...

Not always. I would do a smoke test to see if you have any vac leaks first. The reason I say this is that you are having similar symptoms to when I would blow the filter out of my Missing Link. At first it would take forever to idle down, then once it warmed up, it would almost die during shifts.