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  • 11/7/2012
Originally posted by talonIV
Oh now that is a good link! I need to save that to my DSM repair file on my computer. Although my idle never surges more then 300rpm and always stays below 900rpm at idle. It's like the ISC cant open enough or is clogged.
Hmmm, in that case and my limited experience, I would check the functionality of it via the test coils, give it a quick clean and without link assume that it is reaching 0 or 100 percent and is maxed out, meaning you need to play with your BISS a bit. At idle from memory, I believe the ISC should be about 30-40. Not sure if you can track that without something like link though...
  • 11/7/2012
Yeah i would need Link and I am scared of the BIss hahaha!
If you talk the talk, you better crankwalk the walk.
  • 11/7/2012
Originally posted by talonIV
Yeah i would need Link and I am scared of the BIss hahaha!
Haha, its just one simple screw! The ISC is trying to keep your car idling at what, 750RPM stock? A reason you could be just slightly surging is the ISC is right near its limit so turning the screw one way may put the ISC back into its middle range so it can properly adjust to keep the idle strong.
  • 11/7/2012
I am just weary of the issues that can happen when playing with the BISS. Creating a worse condition then there already is. Yeah idle is supposed to be something like 700-800rpm. Ok one thing that has confused me about Mitsubishi is, when we know how to control idle via ISC/IAC, why the need for a BISS?
If you talk the talk, you better crankwalk the walk.
  • 11/8/2012
Originally posted by talonIV
I am just weary of the issues that can happen when playing with the BISS. Creating a worse condition then there already is. Yeah idle is supposed to be something like 700-800rpm. Ok one thing that has confused me about Mitsubishi is, when we know how to control idle via ISC/IAC, why the need for a BISS?
The way I see it there are 3 purposeful air leaks around the throttle body at idle. The IAC is a stepper motor controlled by the ECU to regulate the idle speed and will try its hardest to maintain what the ECU wants to see, but has a limit in how much/how little air it can bypass. The FIAV acts kind of like a choke when the engine is cold and lets more air bypass the throttle until it warms up and closes that bypass off. Then there is the BISS, my thinking the BISS was Mistu's way of being able to do a quick adjustment to fine tune things as the throttle plate and IAC start to get dirty and don't operate quite the way they were designed when clean. So instead of taking everything apart, risking breaking some parts, the mechanic can just turn the screw a bit to even the idle out and still charge a full hour of labor for it! winkYeah, if the BISS isn't the culprit then adjusting it will create more problems for sure! Unless you are talking about cracking the gasket or screw itself and the BISS is the actual issue, it shouldn't be a scary thing to adjust!
  • 11/9/2012
Actually I was talking to my buddy that sold us the 95 Talon and we both agreed that adjusting the BISS for now to smooth things out would be fine. It's almost like the BISS is supposed to be the forbiden fruit on the car haha! Yeah I can see why mitsu would have all that to regulate idle. Never ceases to amaze me how one company will keep it simple with just measuring intake temp and the isc and others, well, like mitsu have the few gadgets to go along with it. So I am gonna adjust the BISS for now till a proper diag of the ISC can be done and parts replaced if need be. We also both agreed with the MDP codes it is just time to go with a 1G intake manifold with a blocked EGR.
If you talk the talk, you better crankwalk the walk.
  • 11/9/2012
Originally posted by talonIV
Actually I was talking to my buddy that sold us the 95 Talon and we both agreed that adjusting the BISS for now to smooth things out would be fine. It's almost like the BISS is supposed to be the forbiden fruit on the car haha! Yeah I can see why mitsu would have all that to regulate idle. Never ceases to amaze me how one company will keep it simple with just measuring intake temp and the isc and others, well, like mitsu have the few gadgets to go along with it. So I am gonna adjust the BISS for now till a proper diag of the ISC can be done and parts replaced if need be. We also both agreed with the MDP codes it is just time to go with a 1G intake manifold with a blocked EGR.
Haha... cats being skinned... multiple ways I guess.
  • 11/10/2012
Originally posted by drxlcarfreak
Haha... cats being skinned... multiple ways I guess.
Haha pretty much! Well yesterday I adjusted the BISS out 3/4 of a turn and she seems to idle fairly smooth at 600is rpm. I will be happy with that until I get the actual problem resolved.
If you talk the talk, you better crankwalk the walk.
  • 11/11/2012
Well I had a chance to fully read that diagnosis link you posted drxl. That is a DSM must have article haha! Only question I have in his diagnosis is, he mentions unplugging the idle stop switch... Well on a 1G that can be done. But on a 2G throttlebody the Idle Stop Switch is integrated in the Throttle Position Sensor. Also He talks about using an ohm meter over the 4 pins in the ISC. Doesnt the 2G have 6 pins? So if this was meant for more of a 1G, would most testing procedures be the same for the 2G?
If you talk the talk, you better crankwalk the walk.
  • 11/20/2012
Sorry for the late reply! Hmm, that is correct I guess. My 2G has a 6 bolt in it so it lines up perfectly for me haha. I wonder if there is a 2G version. Yeah other than the pins and the Idle switch being integrated with the TPS everything would be the same. If the 2G has 6 pins, there should be a way to ohm it out to make sure that it is in working order as well. When I get home tonight I will look through my Chilton and see what it says...

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