idle screw

[galantlvr34]

does anyone know where the idle screw is located?i am trying to help tgc member P'NOYcaL.does anyone have a picture of the location of the idle screw?thanks.

[4g63lover]

its on top of the TB. Though, I would advice not to mess with it. The ECU does enough calibrations to let the car idle properly. Adjusting the BISS screw will only mess up the fuel trims and will only hide the true problem.

[galantlvr34]

its on top of the TB. Though, I would advice not to mess with it. The ECU does enough calibrations to let the car idle properly. Adjusting the BISS screw will only mess up the fuel trims and will only hide the true problem.

he told me he adjusted it before and he adjusted it and it turned the check engine light off,and now he hears a hissing sound like air is leaking.

[4g63lover]

he told me he adjusted it before and he adjusted it and it turned the check engine light off,and now he hears a hissing sound like air is leaking.

yeah because the screw is probably too far out creating a fixed orifice. close the BISS screw all the way and clear the code and let the car learn how to idle.

Opening the biss screw is like pouring water down someones throat who is already under water. You are diluting the mixture with unmetered air now.

[galantlvr34]

yeah because the screw is probably too far out creating a fixed orifice. close the BISS screw all the way and clear the code and let the car learn how to idle.

Opening the biss screw is like pouring water down someones throat who is already under water. You are diluting the mixture with unmetered air now.

alright i will let him know what you said.

[showtime]

sorry for the thread jack but whats the proper idle RPM? I seem to be idling extremely low (nearly around 500) and I feel like my car is going to die at idle

[galantlvr34]

sorry for the thread jack but whats the proper idle RPM? I seem to be idling extremely low (nearly around 500) and I feel like my car is going to die at idle

its alright i posted it to help someone else out.i have been told 800 is a good idle.did you ever put a new alternator in your car?i know these cars are known to have these kind of problems when the alternator or battery are going bad.

[showtime]

alternator is about 6 months old

[galantlvr34]

alternator is about 6 months old

what about the battery?do you have a multi meter to measure your volts?if you do it should read 14 volts while running.did you ever clean your throttle body out?

[Stavy6]

If i screw the BISS screw all the way down disconnect the battery will the car idle fine? i had a problem a few months back and car had to get fixed at my school by votech. The kid said they played with that screw to try and figure out the problem. I idle at 1000rpm. But am also hearing that hiss sound too.

[mko]

yeah because the screw is probably too far out creating a fixed orifice. close the BISS screw all the way and clear the code and let the car learn how to idle.

Opening the biss screw is like pouring water down someones throat who is already under water. You are diluting the mixture with unmetered air now.

This is not correct!

The BISS screw has an o-ring that seals the the TB from unmetered air entering in the IM. The BISS operates by letting air in the IM though internal TB passages which sets the Base Idle. A base Idle means the revolutions of the engine w/o the help of the idle control valve (ISC). The base idle is usually set by using a logging tool whick monitors the low fuel trims.

What you're telling him, to screw in the BISS screw all the way and let the ECU relearn is not how it is done and it only masks the problem instead of fixing it. The symptoms will reoccur since there's an actual problem.



Simplest way to do it w/o logging tool.

Disconnect battery terminal and the ISC plug
Get a new BISS screw o-ring seal and a cap and replace them. Screw in the BISS all the way and reverse it a full turn. Connect battery terminal and start the car with the ISC unplugged (it may throw a code for that). If the car doesnt start the unscrew another turn, if it starts and it idles too high then screw it in some more. The point is to get the car idling steady at around 900 rpms. Shut the car off, plug the ISC connector. Start the car, if it idles the same good, if it doesnt then adjust to 900 rpms again. Unplug the battery, wait 5 min, connect it again, the idle should be still 900. Go for a drive with lots of traffic lights for at least 20 min. Make a stop, put it in Neutral and check idle, adjust if needed.

These are the part numbers for DSM. The 8g guys who have played with it should chime in and say if these are the correct part numbers

Biss Screw Cap MD614150
Biss Screw MD614948
Biss Screw O-ring MD608806

[P'NOYcaL]

before we start throwing something on this thread i just wanna make sure we're on the right track here guys and i appreciate all your help. So here's the screw i'm talking about in a circle.
i apologize for poor picture.

[P'NOYcaL]

This is not correct!

The BISS screw has an o-ring that seals the the TB from unmetered air entering in the IM. The BISS operates by letting air in the IM though internal TB passages which sets the Base Idle. A base Idle means the revolutions of the engine w/o the help of the idle control valve (ISC). The base idle is usually set by using a logging tool whick monitors the low fuel trims.

What you're telling him, to screw in the BISS screw all the way and let the ECU relearn is not how it is done and it only masks the problem instead of fixing it. The symptoms will reoccur since there's an actual problem.



Simplest way to do it w/o logging tool.

Disconnect battery terminal and the ISC plug
Get a new BISS screw o-ring seal and a cap and replace them. Screw in the BISS all the way and reverse it a full turn. Connect battery terminal and start the car with the ISC unplugged (it may throw a code for that). If the car doesnt start the unscrew another turn, if it starts and it idles too high then screw it in some more. The point is to get the car idling steady at around 900 rpms. Shut the car off, plug the ISC connector. Start the car, if it idles the same good, if it doesnt then adjust to 900 rpms again. Unplug the battery, wait 5 min, connect it again, the idle should be still 900. Go for a drive with lots of traffic lights for at least 20 min. Make a stop, put it in Neutral and check idle, adjust if needed.

These are the part numbers for DSM. The 8g guys who have played with it should chime in and say if these are the correct part numbers

Biss Screw Cap MD614150
Biss Screw MD614948
Biss Screw O-ring MD608806

very nice detailed info there mko! can someone just verify those parts before i start ordering them please. thanks

when you say ISC (idle control valve), are you talking about the IAC(Idle Air Control) valve? just wanna make sure were in this same area.
here's a picture of what im talking about pulled it out of jigz thread:

[mko]

yeah its the same. iac=isc

[galantlvr34]

yeah its the same. iac=isc

is that the right screw that P'NOYcaL has circled in the picture?

[mko]

it looks like, i cant really zoom in to see better

you can go to your local hardware or parts store with the BISS screw and get a o-ring, the closest size they have, of course, while you're waiting for the parts to come. There should be no hissing anywhere on the TB.

Also the threads in the BISS hole should be cleaned up prior to installing the new o-ring. There will be a lot of gunk from the EGR valve deposited on the BISS, and that gunk can damage the new seal while you're installing it. Try using the BISS screw itself (w/o the o-ring) as a tap and run it a couple of times thru the threads, use some parts cleaner and compressed air to dry the cleaner before it gets to the ISC

[galantlvr34]

it looks like, i cant really zoom in to see better

you can go to your local hardware or parts store with the BISS screw and get a o-ring, the closest size they have, of course, while you're waiting for the parts to come. There should be no hissing anywhere on the TB.

Also the threads in the BISS hole should be cleaned up prior to installing the new o-ring. There will be a lot of gunk from the EGR valve deposited on the BISS, and that gunk can damage the new seal while you're installing it. Try using the BISS screw itself (w/o the o-ring) as a tap and run it a couple of times thru the threads, use some parts cleaner and compressed air to dry the cleaner before it gets to the ISC

ok so he adjusted the right screw then?if you right click the picture and save it then you can go to paint and zoom in on the screw.