Wierd Idle problem...BOUNCES

[Coder24]

When I start my car when the motor is cold it will idle at 2k. Then when the car is alittle warmer it bounces from 2k to 1500 then when the car is at the ideal temp(needle directly up) it idles about 800. My 1g mas is hacked and I dont have any emmisions...all has been removed. I'm also running a little rich...could that be because the mas is hacked? Thanks for the help.

 

[Dream On]

Sounds about normal to me, besides the bouncing. Check the ISC coils' resistance. It's really easy and is a common problem related to idle surge.

Running rich is probably the MAS. I really don't think hacking it does any good. It made my car run like crap until it was replaced with a stock 2g mas.

 

[chanley talon]

Hey did you change the basic idle set screw since you hacked your maf? Because you have gained more airflow the computer is more than likley riching it up due to the air flow.

Your computer has 2 maps in it . 1 basically below operating temps and 2 normal temp ranges . 195 degrees is where your temp should be when setting you idle and your timing . However this sounds like biss screw need adjusted and or your isc is dead.

 

[Coder24]

Hey did you change the basic idle set screw since you hacked your maf? Because you have gained more airflow the computer is more than likley riching it up due to the air flow.

Your computer has 2 maps in it . 1 basically below operating temps and 2 normal temp ranges . 195 degrees is where your temp should be when setting you idle and your timing . However this sounds like biss screw need adjusted and or your isc is dead.

is the ISC the same as the IAC? Do you know how much they are? can you get them at autozone? is it easy to change? what about the BISS? can i get that there too? how much?

 

[Coder24]

also im getting a 1g mas unhacked for free in the next few days so ill be as far as the air fuel stuff. and on a side note do i HAVE to run premium?

 

[Dream On]

Yes. Either run premium, or use the shitty gas, get shitty performance, and have shitloads of knock (detonation).

 

[Coder24]

Yes. Either run premium, or use the shitty gas, get shitty performance, and have shitloads of knock (detonation).

thanks appreciate the help

 

[chanley talon]

You already have a biss screw right . Its located right on the throttle body sometimes covered by a black rubber plug or cap . As far as the iac or isc they are the same . Yes it is easy to change . Yes it will cost a truck load new. However you may need to just adjust the basic idle set screw. als known as biss. Their is a faq around on how to do this.

 

[chanley talon]

Heres the link to set the basic idle . http://www.vfaq.com/index-main.html

 

[Whammydill]

I used to have bad idle surge like that, it turned out to be my ECU. You might wanna pull yours and check for any capacitor leakage/damage

 

[Coder24]

well... I havent changed the biss yet. but when screw it all the way down the car doesnt die which is really weird. How do I get that screw out? I tried pulling it today and it wont come out. I screwed it all the way out and had a magnet on itand nothing.

 

[edenTSI]

my 91 used to do that until i altered the BISS screw. actually i paid 30$ for a computer diagnostics because i couldnt find the problem. they were too stubborn to tell me the exact problem (hoping i would come back again, because it started doing it again). but i bought a haynes manual, altered the screw and PRESTO! no more idle surge! and no more idling at 2K. i used to also in cold weather. now it runs at around 1500rpm in cold weather and stays at 800rpm when warmed up. sometimes that BISS screw works its way out. just play with it again and you should fix your problem.

 

[meliketoball]

I took off my recirculation hose connecting to my intake piping to my BOV. When I took it off, my idle bounced and I ran rich for a bit. So if you took that off plug it back up?

 

[97redEclipse001]

my 97 gs did that for a while. I put some injector cleaner in just before fueling up, cured my idle bounce.

 

[Coder24]

my 91 used to do that until i altered the BISS screw. actually i paid 30$ for a computer diagnostics because i couldnt find the problem. they were too stubborn to tell me the exact problem (hoping i would come back again, because it started doing it again). but i bought a haynes manual, altered the screw and PRESTO! no more idle surge! and no more idling at 2K. i used to also in cold weather. now it runs at around 1500rpm in cold weather and stays at 800rpm when warmed up. sometimes that BISS screw works its way out. just play with it again and you should fix your problem.

FIXED! Thanks! once i get time and money im pulling the TB off and cleaning it. But the biss was the culprit. the o ring was kinda like off track it seems

 

[chanley talon]

You know a good way to remove the biss screw to change the seal is to loosen it all the way up and with the car running in neutral with emergency brake on . Rev it up and keep your hand over the screw cause it will blow out. Ive done it.