hey guys,I have the "old school" stage IIa in my car and my idle fluctuates a couple hundred rpm when it gets up to operating temp.when it's dead cold it idles perfect.I don't have an idle motor as of yet,but is this something I can tune out :?
what is your mixture like at idle? Are there any drastic changes in the fuel map or tps map around the idle point?
I never had a problem getting a nice steady idle with the first system, and it's rock solid still with IIb, and I have yet to hook up an idle controller. It idles rather low when cold w/o the idle valve, but I haven't had a problem with it yet once the engine get some heat into it.
well,there doesn't seem to be any major differences in the fueling,the two matrix boxes that the values are in are almost identical,but the air/fuel mixture does kinda fluctuate though,rich-lean rich-lean on the lambda.when it is cold it does idle about 800-900rpm,which is where I'd like it to be when it is hot.I also have a blua 272 cam if that makes the difference.
Derek, have you messed with the Closed Loop parameters, maybe you need to slow down the O2 correction speed, try changing the EGO loop rate and gain parameters, I bet that smooths it out. Also, ensure that you're not trying to put in too much EGO correction, if its over 1.05 or under .95 then your base settings are off and you need to keep the EGO working in a narrower range.
It sounds like at idle you're going rich-lean-rich-lean which sounds like the EGO settings.
On my 4000 turbo with the old school fuel only computer my idle stays pretty smooth. As nate mentioned, sometimes it will idle a bit low when cold but it comes up about right once things warm up. I also added a CIS warmup valve to my car to help add a dynamic amount of air (they use a heater element to allow more air when cold and less when warm). I have since disconnected the connector on it and just use it as a one-way-valve protected source of idle air (my idle screw didn't seem to add enough air past the throttle body).
ok,I did a little tuning today,and what I found is....( suspence) not much.the correction is within .95-.105 unless i have a really light foot,then it goes a little bonkers( up to 1.13 or so) and when I tried to correct,it doesn't really do anything,and I made sure the 02 correction was off.i did mess a little with the ego correction rate and speed or whatever it is and it didn't do anything either.as long as I don't go in to the really high vacuum,it's fine.and i think I also got the idle fixed,it doesn't seem to be fluctuating any more.,and javad,remember the surge I was telling you about? it did it again,but this time I was hooked up and could see what it was doing and because I never revved it out before,I still had all the values set at 1.00 above 5500rpm,instead of 1.25-1.30 like the rest,so oops :tard: I was runnin it lean.but it's all fixed now and the 02 is reading .95 under all hard acceleration, .93 under cruising,the map correction is is about .98 most of the time and the ego correction almost never moves from 1.0.I also was looking at my intake temps,under WOT 2nd -4th, it never reached 70 degrees celcius,mostly about 65 degrees.so not too bad for no intercooler,eh.but,i know the temps will rise as soon as the boost goes up,so I will have to intercool it.it's runnin' real sweet right now and i didn't realize it but the rev limiter was set to 7k and I was revving it pretty close to the limit,so the blua 272 cam works good,it pulls from the bottom til' the cut out