2G BISS boost leak?

[idlehand04]

Hey guys,
Im new to the dsm world and need your help. I have read multiple forum and search for day for a answer so here i am.

My 99 Eclipse Gst with fmic, upper ic, and k&n cone filter has some weird idling problem. Most of the time it idles between 750 to 900, times it lower at 400 - 600 and sometimes higher at 1200 - 1500. When I turn on the heater my rpm will raise and sit at about 400 more then the current idle.

I just done a boost leak test and found a big leak coming from the biss screw. I already have a new o ring, screw and cap. I understand all the different way to get the screw out to replace the o ring.

My questions are,
Should all other leak be fix before moving to the biss screw?
How to adjust the biss after I replace it without a scan tool?
Will I need to go to the dealers to have the adjustment done? (if the only way is with a scan tool)
Should I leave it as is and just rtv the hole (if that really works)

Please help me.
Thanks

 

[92AWDHX40]

first i would do a blt, and fix those first.

 

[idlehand04]

Ok will do. Any suggestion on the biss?

 

[92AWDHX40]

Replace the oring and the screw itself, make sure you take care of any other ones, i use link to help with idle, never used anything else. Dealer can do it too, but you can spend some money there, i avoid dealerships i try everything myself first, usually it just takes time to figure out some problems.

 

[1995silvergst]

When turning the biss out count the revolutions and repeat the new one back in. You may also be hearing some air from the throttle shaft seals as they are very close to the biss.

 

[idlehand04]

I use the soap water and found only the biss leaking from the tb area. I will be fixing all other leak before the biss screw. Does the counting the turn really work? have you or anyone done it that way?

 

[Afizzle]

You needed to plug the BISS opening with your finger and continue testing. Air takes path of least resistance meaning biss was your worst leak but not your only leak. You don't need a dealer o ring either. Take the old o ring to a parts store and they'll match it for 25c. Replace o ring and retest. From now on dont stop with the first leak. Plug it with your hand or finger and listen/spray any other leaks to get em all in one run.

I use the soap water and found only the biss leaking from the tb area. I will be fixing all other leak before the biss screw. Does the counting the turn really work? have you or anyone done it that way?

It's not that serious. Get as close as you can and adjust after starting the car and getting to operating temp. Get it close to 750 as you can. Your ecu will actually correct the idle and bring it back down to factory settings over time regardless. Don't make readings of your rpm at idle unless your car is at operating temp. At that point anytime you turn on an accessory, like your heater, it shouldn't effect your rpm as much as if the car was cold.

As for the counting, I just count how many turns until its all the way IN. Then when I reinstall, I screw it all the way in and back it out however many turns recorded.

Oh and btw you own a dsm, GL getting a perfect idle w/o engine management.
My 2 cents

 

[1995silvergst]

^^ exactly the ECU will adust with the IAC you just need to be close, also the biss screws are manufactured to the same length/thread count so counting in or out theoretically should be the same.

 

[idlehand04]

I wasn't looking to get the perfect idle. Just nothing to high or to low Awesome! that is the type of answer i was looking for. Thank Afizzle. I will retest tomorrow that way and see what comes up.

 

[Spanky_DSM]

I use the soap water and found only the biss leaking from the tb area. I will be fixing all other leak before the biss screw. Does the counting the turn really work? have you or anyone done it that way?

I cover the biss screw with some RTV and no more worrying about the orings inside the screw

 

[snowborder714]

If you ever need/want to have your throttle body rebuilt, I'd highly advise not just filling in the BISS hole with RTV. It doesn't make the rebuilder happy to have to dig all of that out. A new o-ring will solve the issue

 

[Spanky_DSM]

its not as bad as you make it seem. You just take a heated knife and it comes right off like butter.

But I see your concern after reading your signature haha.

 

[idlehand04]

Sorry for the late update guys.
I replace the o ring and screw and car is running much better. +1 on counting the turns before replace the biss screw.

Thank you for all the help.