Cool intro story: friend gave me his bone-stock 99NB (10th anniversary) for an MS2enhanced and WBO2 install.

Install went perfectly fine after we figured the DB15 pinout. Wideband gauge (AEM failsafe 30-4900) and tunerstudio agree to the decimal on AFR, so must've done something right

Started up on the first try, needed some small VE adjustments for a decent idle. Had idle control switched off for now since I'm lazy and wanted a decent baseline first. The very second I enable PWM CL idle control it's all over the place: revs to ~3k back to ~1.1k before I get fed up and shut it down. No amount of messing with idle settings clear this up. Had to manually edit the frequency modifier to 16 to get close to the 500Mhz the NB idle valve wants.

Before I take it out for a drive and look like a fuckbag at every trafficlight, what else is there to change? I can't sit in front of my house making noise all the time so I can't really spend hours messing around with just idle settings.


More info:

bone-stock 1999 NB 10th anniversary model, no AC, just PS, OEM 240cc/min injectors, aftermarket muffler and cone filter on 90 degree elbow of the TB with the IAT sensor wired in.

Logs and current tune attached. (one in zipfile due to size)

x0x0

 

Wait... he gave you the car after you installed an MS2E and WBO2? Like for keepsies?

 

I wish. I'm just installing/tuning it for him.

 

Read Braineys "quick and dirty closed loop idle tuning" post. Actually do it. And yes that involves sitting outside the house and messing with it, no way around that. You wanna calibrate all sensors/thermistors, you wanna do the idle valve test and plug in those values, then you wanna follow his quick instructions on dialing in PID.

Until you have a good solid idle and startup there's almost no point in tuning further. Tuning the ve table and setting up the spark table is cake, and the least of anyone's worries. Takes me like an hour or two to do that, but the REAL tuning on a street/daily driven car is all the trims and settings, enrichments, etc. That's where you'll spend a week if you want the car to run better than OEM and perfectly

 

All Enhanced MS2s require a multiplier of 1, as there is a hardware multiplier inside the ECU that ups the frequency to 488Hz (your unit) or 493Hz (newer units).

 

Thanks Vlad, found he post. Will try this tomorrow. It's not the tuning that's bothering me, but it feels like being a dick to my neighbors when I'm just outside revving and ******* with it for hours at a time.

Dimitris: will alter that first thing tomorrow. Did the 16 multiplier **** up anything? Idle valve wasn't particularly hot after 15 minutes or so.

 

if its bone stock I can't imagine it would bother anyone. our cars are pretty quiet

 

Stock except for the look-at-me-double-exit-muffler

 

Find a parking lot :-)

 

Which brings me back to needing at least some driveability and idle

 

No, increasing the multiplier doesn't mess up anything (permanently) but it can produce the symptom you described.

But from what I can see, its all just settings. The idle valve is opening up too much based on the target RPM error.

 

Good good. Will have another go at it in the morning. Thanks.

 

Not sure if you've seen it already, but there's another active thread about someone with idle issues... I was having idle issues as well, and was able to fix it with all the info/links contained here: Link

 

I had another go today, went waaaay better. I babied through warm up, tried the idle valve test. Opened the bleed screw on the throttle body half a turn and had a go at it.

under 26% PWM, idle stays the same at ~880 rpm, adding up to 38% lets it gradually climb to ~1500 rpm. (Do I need to go higher here actually or will this give enough resolution?)

Idles around 1100 rpm now with ~32% idle PWM. Tip-in is a little lean but comes back nicely to stoich. Catches idle pretty decent when blipping the throttle and letting it come down, same for opening/closing the windows. Feels like such a big step to have gotten this far at least.


Current tune and log attached, comments?

 

Don't have the time to open the tune/log, but the values you mention sound absolutely the norm to me.

 

Good, thanks. Have a look at the tune when you get a chance. Do I absolutely need to get the idle PWM up to 100% to what RPMs I get or is this sufficient? I'd like to see ~1500rpm cold idle, tapering off to ~950 hot.

 

There is no need to hit any particular duty cycle for the idle valve. Going to 100% is part of the testing procedure so that you can fill in the closed loop idle parameters, but it shouldn't hit 100% unless you warm rpm is set very high (ex: over 2000 rpm)

 

Small update after a spring install delayed me a bit. Cold start is decent, starts on first crank and doesn't die on me so that's good.

Now, whatever I do I can't seem to enter CL idle. Regardless of settings the idle valve puts out 34% PWM and hovers around 1100rpm hot. I've read braineys quick 'n dirty guide and also hornetballs explanation on entering CL idle. My settings look reasonable (to me at least) but no dice.

When I enter the idle valve test mode it reacts to PWM changes (more PWM increases RPM). Changing I term in PID from 50 all the way to 150 has zero effect (P and D are 0 for now). What am I missing here?

I seem to have some TPS jitter (-1 - 1%) so I raised the TPSdot to 3.5 or something.

Took a short drive, bucking all over the place due to lean conditions so there's lot of VE tuning to do, but I feel like I should get this idle sorted out first.

Any input?

As always, current .msq and logfile attached.

 

Another update, seems to enter closed loop idle now. Slowly increasing I-term decreases RPM closer to target while lowering idle PWM so I'm getting there.
Screenshot shows while highbeams, rear window defrost and heater (setting 2) are on. This is the first time I've noticed the CL Idle indicator light up in green.

Only issue I'm running into here is coming to a stop still stalls the car. Do I need more I-term here or are my dashpot settings off? I still need to find out how to tune while also driving

Took a small drive, was still bucking like I've never driven stick before because it was lean all over the place. Pulled over and added fuel across the board (~20 points in cruise areas, fattened accel enrichments). The second I commence VEAL again it starts pulling fuel again until the bucking comes back. Why is it fighting me?

As always, tune and log (zipped due to size) attached.

Halp and push me in the right direction

 

You want to open the idle screw on your throttle body so that the engine is getting enough air to idle even if the IAC was completely closed. That will prevent the engine from stalling.

ps. never post a file called "CurrentTune.msq". Many of us don't want to OverwriteMyCurrentTune.msq ..

EDIT: As you already noticed, there is something very wrong with your VE table. No wonder it's bucking..