bad idle, slow acceleration, rattling noise when starting... help!

[clipse0001]

OK... i got a 97 gs-t at a used car dealership. it was fine for the first couple of days but now it is all messed up. The idle is really bad when i stop at a light. the car will go from about 600 to 200 rpm back and fourth acting like its about to die. when i rev the engine up to about 1500 it will drop back down to 200 or so and start bouncing off of that. this kinda goes away when the AC is on so thats what i do now... KEEP THE AC ON ALL THE TIME. the other thing is when i accelerate in first gear it goes fine to about 2300 but then it slows down till 3500 or so. the car also makes a rattling noise when i start it. i think thats because the starter is sticking but im not sure. can anyone help me out on this one. i have a small hole in the exhaust pipe right next to the rear axle. the car has a 3 inch exhaust.
thanks
anton

 

[RedRain]

Check your Mass Airflow Sensor.

 

[clipse0001]

Check your Mass Airflow Sensor.

I cleaned that today with some no residue throttle body cleaner and it only got worse for a couple of hours and that continued with the same crap as before

 

[RedRain]

Cleaning it might not do anything to it. Try to find some specs and test it for Resistance or if you know anyone who has a car like yours, you can just swap them and see if it is it.

 

[utkanf]

Did you check all the intake air piping for leaks. Or ignition coil pack. Hope it helps.

 

[hiimt0ny]

does you car kill when you take left turns? if so then you might have crankwalk.

 

[ddavisaf]

Crankwalk this crankwalk that BAH!

First, check for boost leaks.
Second check for boost leaks.
Third fix the boost leaks. Yes, you have boost leaks.
If by chance you don't have a boost leak....
Check your TPS, then your ISC.

Your MAF is like 3 or 4 steps down the road from here.... don't even worry about it yet.
Here's how to check for boost leaks
How to check your TPS
There is a bit of info in that one. So read for a bit...

 

[clipse0001]

so i was looking around my engine bay today and i realized that my BOV is broke. that little tube that comes out the top is broken off and missing and there is no hose there for it. does anyone know where that thing USED to go to. i am talking about the 8mm little tube that is supposed to come out the top side of the valve. anyone know where it goes?
thanks

 

[ddavisaf]

Man I'm good... what kind of BOV?
You really need to update your profile with your car's information. Even if it's stock. That way I could of just answered your question instead of having to wait on a reply to see if it's stock or not.

 

[clipse0001]

i jsut updated my profile. as you can see it is all stock except for the 3 inch catback

 

[ddavisaf]

http://members.shaw.ca/dsm.1000q/Engineprimer/

 

[halligoo]

Folks that are Crankwalk happy should drive pickup trucks.

 

[oldman]

so i was looking around my engine bay today and i realized that my BOV is broke. that little tube that comes out the top is broken off and missing and there is no hose there for it. does anyone know where that thing USED to go to. i am talking about the 8mm little tube that is supposed to come out the top side of the valve. anyone know where it goes?
thanks

That hose goes to the intake manifold and it must be connected. I hope that you have not been boosting around with it not connected.

1. The BOV will not blow off without the vacuum hose hooked up causing compressor surge, hopefully your turbo is still ok. Do you hear anything weird when you let off after boosting?

2. Depending on whether the nipple on the intake manifold is caped off, this can very well be the cause of you idle surge not to mention a huge boost leak.

3. Make sure the BOV isn't vented.