Installing/Setting new BISS

[BrandonDouglas]

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.

[KevinBuckham]

Yes, you want to match the procedure to the ECU.  I don't know of a way to do the BISS test *properly* on the 2G w/o the scan tool or ECMLink.  (I don't believe you can just ground anything like you can with a 1G.) Personally I'd get the car to full operating temperature and try to find the two limits (too far in, and too far out).  Assuming the ISC is perfectly functional, it will take some time for the ECU to fully compensate for a BISS change, and one direction has a faster compensation than the other (I forget which).  Once you find those limits, I'd set it a bit closer to the "too far out" since the ECU normally won't need less air to idle under most conditions but will need more air when performing warm up, and activation or power steering and A/C.

Oh yeah if you're ISC isn't functioning properly (perhaps 1 dead coil), you'll be chasing your tail.

[John Hartman]

not sure on the exact procedure for a 2g, but assuming everything else is functioning correctly, too far out will cause idle surge, so turn it in a bit till it doesn't do that?

[BrandonDouglas]

Yes, you want to match the procedure to the ECU.  I don't know of a way to do the BISS test *properly* on the 2G w/o the scan tool or ECMLink.  (I don't believe you can just ground anything like you can with a 1G.) Personally I'd get the car to full operating temperature and try to find the two limits (too far in, and too far out).  Assuming the ISC is perfectly functional, it will take some time for the ECU to fully compensate for a BISS change, and one direction has a faster compensation than the other (I forget which).  Once you find those limits, I'd set it a bit closer to the "too far out" since the ECU normally won't need less air to idle under most conditions but will need more air when performing warm up, and activation or power steering and A/C.

Oh yeah if you're ISC isn't functioning properly (perhaps 1 dead coil), you'll be chasing your tail.

Gross!
I've been chasing an intermittment idle surge for a while now.