Setting BISS

[Rice80]

So my BISS, o-ring and cap arrived in the mail today from RTM, I am going to go install it and properly set it following the vFAQ.

Question is though, I have a 6 bolt motor, but a 2G ECU. Do I follow the 1G or 2G procedure for setting the BISS? The BISS must correlate with the ECU I would think?
Only thing is I don't have the scan tool they talk about for setting the 2G.

 

[blazindominic@n]

i suggest screwing it down all the way and loosening as needed that's the way i did it when i bought a new one for my 6 bolt swap into my 2g. you can tell from the idle if it needs to be tightened or loosened.

hope that helps

 

[gusu]

i suggest screwing it down all the way and loosening as needed that's the way i did it when i bought a new one for my 6 bolt swap into my 2g. you can tell from the idle if it needs to be tightened or loosened.

hope that helps

Uhh no... If you go too far you will bottom out your BISS which will either be a bi*** to get out or it will break the o-ring when trying to remove it. I suggest putting it in a quarter of the way and going from there to have plenty of room to play.

Follow the 2g guide.

 

[Rice80]

Uhh no... If you go too far you will bottom out your BISS which will either be a bi*** to get out or it will break the o-ring when trying to remove it. I suggest putting it in a quarter of the way and going from there to have plenty of room to play.

Follow the 2g guide.

The only thing is I don't have the scan tool they talk about..

 

[spawn87]

## best bet is to take to a shop so they can hook it up to a scan tool and check the isc position (which is 30 at idle) its the fastes and less stressful way to do it... if not find a buddy with ecm link who is willing to lend it to you

 

[DSM1G90]

You have to set the ISC unit first before fiddling with the BISS screw. VFAQ Site - Visual Frequently Answered Questions has tips on setting the ISC first ..

 

[LiquidX]

Spawn87 and dsm1g90 are correct, your BISS placement of is actually setting the proper travel for the ISC so you have the specified travel distance for maintaining property idlevof 750 rpm on a stock ECU.

 

[Rice80]

I cannot seem to find anything on setting the ISC..

 

[LiquidX]

In a nut shell, the diagnostic pin at the obd2 plug needs grounded out to stop the movement of the IAC by the ECU and you'll slowly adjustable the BISS to achieve 750 RPM. You want to make sure you have an air-leak free system though.

VFAQ Site - Visual Frequently Answered Questions look into it.
2G BISS Adjustment

 

[bsbllfit7]

Is there a way of grounding the diagnostic pin without using a scan tool? Like connecting a wire to a certain pin and grounding that out? Just trying to see if I can do this without a tool. Also would the scan tools from autozone work for this purpose?

 

[DSM1G90]

(Why do people go to Autozone?)

Easy ... take a length of 18g to 22g wire (about two feet) and solder an alligator clip on each end. That way you can use this jumper to do the base timing or set the ISC when you clip one end to what needs to be clipped on and the other end to a good ground.

Making a jumper like this is the best friend for the automotive/electronics tekkie.

DSM

 

[bsbllfit7]

On obd2 though its not the diagnostic pin in the engine bay i believe, so what im wondering is if there is a way to ground out the pin at the diagnostic plug (aka under the dash).

 

[Dr DSM]

screw it in all the way (but not too hard) then do 2 full turns back. then slightly adjust it from there

 

[bsbllfit7]

^^ Thats not the proper procedure, thanks anyway.

 

[romeen]

Well, you already know the correct way to adjust the BISS. Having said that (and as you are aware), not all of us have access to the scan tool and are left with the trial and error method. If you decide to go this route then the one piece of advice I have is to drive the car for a little while after adjusting the BISS. Even though the idle speed changes immediately when you turn it I've noticed that it may change even more after some driving. On my car the rpm drops down about 200-300 after some driving.

Is there a way of grounding the diagnostic pin without using a scan tool? Like connecting a wire to a certain pin and grounding that out? Just trying to see if I can do this without a tool. Also would the scan tools from autozone work for this purpose?

The scan tool at my local Autozone did not have this feature. I don't know if they all use the same tool though. At the ECU I believe that pins 4, 5, 17 and 18 are all involved in controlling the ISC but I have no idea what it will do if grounding one or all of these. I don't know what pin is involved at the OBD2 diagnostic port. If you're able to do this please let us know.