OK i am pretty sure is a failing Idle Are Control valve but i want to double check with you guys.

Basically i start the car and the engine idle falls and dies or it doesnt die and revs up and falls on its face and keeps doing that for a minute until it almost goes away. Throttle will still bounce a few 100 RPM while idling.

It was real hard to get it home because every time i put it in neutral from over 2000rpm or higher to come to a stop light the engine would fall in die, or get close to dying and doing that bouncing thing from 200 rpm tot 1500rpm and keep bouncing struggling to stay alive.

 

sounds like a vaccuum/boost leak. you should check all connections. do the cheapest checks first.

 

Do you have a vta bov with the maf?

 

^or that. If you are not tuned for VTA, that will definately happen.

 

AT idle i am getting about 20-22 inch of merc. so i dont think that is a vac leak.

sorry i dont know what VTA means.
I have a tial BOV and running AEM EMS.

 

Does your BOV Vent To Atmosphere to is it reciculated back into the intake pipe?

 

Atmo, it was tuned this way. car has been fine for a year. it just started doing this idle bounce yesterday.

 

i think i would re-tune it for re-circ. get rid of VTA imo.

 

This was tuned by Lucas English of English racing, its not the tune.
how would a tune change 6 months later one morning and cause this problem? and no mods have been changed since the tune

 

Are you on speed density? Has the weather changed a lot from the weather the vehicle was tuned in?

 

of course the weather has changed from 6 months ago. but its been colder then it is now, so if that had anything to do with it, it would of showed its head a while ago and the car would run fine in my garage (which it doesnt) since it always the same temp.

I removed the IAC and there was a bit of water in it. If its anything like my last car the IAC should be able to be moved by hand but this one is is not. looking into getting another one.