Multiple Issues *Assistance Please*

[snow3d]

My vehicle is a recently purchased 1992 Talon Tsi AWD.

The balance shafts have been removed.
All vacuum ports on the intake have been capped(I assume that the emissions devices have been removed).
Aftermarket exhaust(3" Turbo back I believe) I haven't had it in the air to be certain.
All of this was done by the previous owner.
Probably the free mods as well.

Here are my issues and my suspicions regarding the symptoms.
1) Overboosting (seems to be only in 3rd and 4th gear) I have the wastegate hooked directly to the turbo compressor(no MBC or BCS). The wastegate seems to work fine in 1st and 2nd but not under WOT at high revs.
Is the exhaust too big?

2) Poor idle (idles @ 2000 when first started cold then surges from 500 to 1000 in gear)(smooths out @ operating temp).
Faulty ISC? O2 sensor? MAF?

3) Oil on the underside of my hood.
Clogged PCV valve? Weak seal on the oil cap? Sending unit related?

From what I gather all of these problems are common to DSMs, it just seems that no one has a definite answer.

Sorry if this post is:
Lengthy
Needy
Unnecessary

If you want to scold me and banish me from your forums I understand.

 

[Lofty]

I can only help you a little.
For the oil on the hood, is there a little filter on your valve cover breather? This causes oil spray on the hood.

As for idle, this is somewhat normal. SOMEWHAT.
It sounds like your ISC is faulty.
The reason your idle surges like this, in simple terms is basically your ecu is noticing that your idle is too high, so it cuts fuel, as soon as it realizes the idle is low enough, it adds fuel, and then it repeats the circuit.
Heres what I did to fix my problems.
First, loosen your throttle cable and re adjust it, sometimes it can stick the throttle open.
Then, you should set your Base Idle, you can look at how to do this here
1G BISS Adjustment

If none of this helps you, it could be a few different things.
Read this guide to fix it completely, it IS once of these problems, guaranteed.
Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

Best of luck! I know it's frustrating, but don't give up.

By the way, surging isn't harmful, so don't fret it. It's just an annoyance.

--Scott

 

[anteversion]

you will have to cure your boost creep by porting your wastegate.
your isc motor is bad and thats why you got erratic idle.
oil might come from your dipstick. When too much pressure is applied to the crank case, oil might comes out by somewhere, so the dipstick pop out and oil is sprayed!

 

[snow3d]

Thanks for the help, I appreciate it.
The idle and oil issues I can manage. More of a nuisance really.

However it's the overboosting that scares me.
Are these cars prone to overboost even with the stock exhaust?
Could I not just put a more reasonable exhaust on it to stop the boost creep as opposed to porting the wasegate(which seems much more involved)? I just want stock boost levels.

 

[Dsmj89]

A free-flowing exhaust, for example a full 3" will raise the chances of boost creep happening. I know it has happened to a few 14b's and lots of 16g's, but as funyn as this may sound, i believe it is happening to my t25, yes my t25 !! Anywho not to get off-topic, either port your turbo's wastegate outlet or run an externally dumped o2 housing.

 

[2gawdtsi]

As far as i know, boost creep isn't a problem stock.

 

[Dsmj89]

As far as i know, boost creep isn't a problem stock.

But however it does start playing part in very rare cases once the exhaust system has been altered to a high flowing system.

 

[anteversion]

As far as i know, boost creep isn't a problem stock.

he said he's got a 3inch turbo back

 

[anteversion]

the fact is that with a large turbo back exhaust like that, the exhaust gases are evacuated much more freely and fast so it have this same impact on the turbine. Turbine rotation speed will raise too much and the wastegate port will be to small to evacuate enough exhaust gases to control the boost amount properly. Wich will result into boost creep.
with a ported turbine housing and wastegate, and o2 housing, you cure this effect.

 

[Defiant]

Don't try to ask compound questions in one post. It doesn't work. And, use descriptive thread titles when you post.