strange idle problem

[nuclearpenguin]

Ok, my idle once started getting higher and higher and has gotten worse and worse. So I decided instead of fiddling around with all the crap (and the butterfly screws i stripped), I would just buy a used TB. I got it in and the day I go to install it, my oil filter housing stud comes loose, forcing me to wait 5 days before getting to test it out. I finally got to fire it up today; I had the jumpers grounded for the BISS adjustment since the TB hadnt been adjusted and I had put in my new biss/o-ring (like 3 weeks old) out of my old TB. I had screwed it all the way in (but not bottomed it out hard) and then backed it out 2 rotations, most people said thats the place to start. I started the car and it idled at like 2000rpm, but even worse; it started climbing! I shut the car down and tried again with the same results. My TPS should be set about right (showing 11.7% on the logger). I tried taking off the BISS jumpers then starting it and it went up to 2000rpm, but then started hesistating, almost like surging.

What could it be? I double checked all my connections and it all looked good...

 

[RossY]

11% throttle at idle? That doesn't sound right. I don't know if its different between 1g and 2g but I strive to keep my tps at 0%. Otherwise your idle switch is never going to kick on. I would play with your tps to get it to 0%. See if that helps.

If that doesn't help then you may want to test your ISC motor. That has been the culprit of high idle and idle surge to me and a few of my friends as well. Instructions on testing the isc can be found at this site http://dmtalon.v8eaters.com/ISC.html

 

[yokotabrat]

RossY, 1gs and 2gs are actually different for TPS values. Logger values on 1gs should show 10%. 11% is close, but it sounds like the throttle stop (idle switch) has been messed with at some point. Things to check: make sure you don't have a leak (pressure test), check the slack on the throttle cable, check the ISC coils with a multimeter.

The more difficult things it could be: FIAV, driver chips that control the ISC in the ecu, incorrectly setup tps and idle switch (there's a procedure in the FSM for how to set this).

 

[nuclearpenguin]

For future reference; I put the old TB back on but fiddled with the BISS. Now my idle is 100% perfect Thanks guys.