New here - 1990 Talon TSI AWD -- Idle problems

[Fubar231]

So i just picked up a 1990 talon tsi awd 5 speed car two weekends ago, (almost 161k on it, P.O. got it at 157k in 2005 and drove it 3k in 8 years). Most of the mods on the car were on it when he got it i believe, but he did just put a new big 16g and other stuff on it.

Heres where the fun begins

The car has a funny idle issue, when you cold start the car it revs like 1500-1800 while its cold as it should, but once it fully warms up it will still idle at 1500-1800. Sometimes if the idle drops below 1500 the IAC/ECU will try to get it down to regular idle, at which it will go from 800-1200-800-1200-800-1200 and surge alot. There is also some times it will just idle at like 1200 i think, but not 100% sure as ive only driven the car maybe 70 miles. Would this be the IAC motor shitting out or could it be caused by other things? One of my buddys whos a big 4g guy said IAC and that was that, but then another guy i know said it could be the coolant temp sensor. What do you guys think it is?

Also the car has following mods from what i know, might have more but

Intake
Big 16G
Full 3" Turbo Back
Balance Shaft Delete
MHG w/ ARP Studs
AFPR
Unknown Injectors (They look factory and have a light blue top)
Fuel Pump (Can hear it just unsure of what it is)
And other random body/suspension stuff but i believe thats the most of the motor work, i could ask the P.O. tomorrow at work (A tech at the dealership i work at)


But please DSMTuners, can you guys give me some help and tell me where I should start!


Thanks,
Fubar231

 

[clipto]

Check out these things,There good for issues with ruff idles. http://www.dsmtuners.com/forums/articles-engine-fuel/191137-how-fix-your-idle-surge-problem.html
http://www.dsm.org/how-tos/tttt/tttt3.html

 

[Fubar231]

Check out these things,There good for issues with ruff idles. http://www.dsmtuners.com/forums/articles-engine-fuel/191137-how-fix-your-idle-surge-problem.html
Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

Alright, ill look through there some. Did it sound like the IAC to you?

The car does run strong it seems, although itll break up past 6k sometimes, could be boost leak or needing plugs, im not sure as i just got the car and havnt driven it much or really looked into it yet.

 

[clipto]

Whats your afpr set to? How much boost are you running. Do you have a boost gauge and a wideband? Get spark plugs ngk bpr7es gap to .028 and use ngk blue spark plug wires. Always good to change fuel filter and check for boost leaks. Can you post a pic of your engine bay too?