Brain MS3X Idle 'Issues' (Idles at 3k)
 

Hey guys!

Brain and stefanst have been super helpful in helping get this sorted, but I figured it wouldn't hurt to ask the community at large. I put issues in quotes because I'm guessing that most of this is operator error (i.e. me being a noob), but I wasn't expecting to have this much issue with a basemap. Wishful thinking, right?

I just got the MS3X installed and everything running. Car starts...most of the time. It idles at 3k and it doesn't drop down once fully warmed up (coolant at 180+). My next step is going to be to work on the idle valve test, but I tried it this morning and dropping from 45 to 44 make it go from 2300 to a stall. So I'm a bit at a loss.

The car is basically on a basemap. I'm attaching the map as well as a log here. I forgot to hit space bar during the log, but it shows the car warming up and then my attempt to start testing the idle valve. Then it stalls. I try starting a few times with no luck. Once it starts up, I give it gas to try to get it to idle, but nothing really happens if I floor it. Blipping the throttle does help a little bit, but it keeps coming back down and just sputters out and dies.

I've been reading the manual and looking up threads for folks working on idle like this one: https://www.miataturbo.net/megasquir...it-miss-84668/
But I feel like I'm not even close to being there yet.

Attaching a log and tune for input. Thanks a ton in advance.

Edit: Whoops forgot something important.
Car is a 2000 with a stock 1.8 motor. Only notable modification is a racing beat exhaust manifold.

I'm at work can't take a look at the files, but perhaps
1) your iacv settings are inverted, or wrong frequency being used
2) you're too far outside the range. start high and work your way down

find the actual working value of your idle valve. did you not drop the min pwm % value back down?


the car stalled from going lean, it had nothing to do with the idle valve. the rpms are idling high, cause the valve can't close enough as currently setup. look at the idle pwm % in teh log, it's pegged as low as it can go despite a 850rpm target.

I mean 3 grand, kinda sounds like a vacuum leak to me???

sounds like he needs to do what we tell 99% of the n00bs in here to do:
actually learn what each table/menu does and start actually intelligently tuning the car vs randomly pecking at settings? lol

:rofl:
Yes, you need to understand the MS in order to use it properly. And run 12's :naughty:

if it was behind the throttle plate and the idle valve was actually fully closed, sure.

Haha 18psi, I wouldn't say that you're wrong. I'm workin' on it!

Sonofthehill, I suppose that's possible and I'll double check when the car is running. It does certainly seem noisier than usual, but I don't usually have the car running at 3k in a garage with the ass sitting out the door so I don't kill myself! The only place I can think of that wouldn't be sealed is where I put the IAT sensor in and I just put that in the stock location after drilling out the rubber washer there. I can put some silicone around there. I don't think that location was all that important for vac though. Other than that, I only added a T for the MAP sensor near the FPR as per brain's instructions and the back of the head for a boost gauge. Vac reading is about 22 from what I recall.

Brain, I'll do that tonight. My AFR's are hitting 18 as the car is idling once warm, which is pretty lean to begin with.

But what if i want to run 13's and understand nothing? Tradesies!
Totally kidding haha. I'm looking up old threads and doing things along with them. There was apparently a good document for idle tuning here: http://www.msextra.com/doc/ms3/Idle_Control.html but it now just reverts to a list of all the manuals instead of that document.

it would have the be behind the TB on the IM.



if youre lean, richen it up :P

SHADDUP AND TAKE MY MONEYYY!!! :rofl:

I tee'd the vacc gauge off there, but it's reading somewhere in 20-22 range, which I've read is normal for these engines.

Side note: I have no idea how folks that install FI and the MS all at the same time with no experience get anything done. There's so much going on and FI really increases the chance of things going boom. I'd be friggin terrified right now if I had my truboz installed....

Are you in Open Loop idle mode? For some reason I was in Open loop idle, and had the same exact problem. I may have changed it, maybe not.. But after I switched to Closed Loop idle, my idle dropped to 850-1000 from the 2500+ it was at before.

Yup, but to be fair startup/idle/cruise areas really aren't affected much and you can always just set boost cut low and/or lower the rev limiter for those n00b moments when you wanna floor it on a base map

I should turn on the coolant temp based rev limiter and watch my car freak the fuck out even more as it tries to start and idle.

Let's go back to basics with your setup. There are too many advanced things going on and possibly fighting each other to diagnose (at least for me). So, please:

- Change to Open-Loop idle (Please Brain- don't yell at me for that!)
- Set your "Idle warmup duty steps" to 45 across the board. It'll be revving real high, but that's the price you have to pay.
- Turn off idle VE, let's just try and tune your idle cells in the main VE table first

Increase your injector dead-time to 1.3ms. That's roughly correct for my NB2 injectors and I'd guess NB1s are similar. 1.0ms for stock injectors seems optimistic.
This will have the effect of your Lambda going richer now. This is desired, since you were running lean-ish anyway, so adding some fuel won't kill you. Idling at a lambda of 11 or even lower won't kill your engine, if you don't do it for hours and hours and dump a lot of unburnt fuel into the oil-pan.

Then check what your engine does. can you drop idle any lower in the test-mode now that you're running richer?

seriously awful advice.

Are you even looking at his logs? You're having a noob change random shit, to what end result?


all he needs to do is 2 things:

1. find the operating duty of his idle valve to bring idle down.
2. increase the fueling the prevent stalling.


Get over your hard-on with open loop idle. You're adding in unnecessary changes for no reason.

look at his log: for 100 seconds he was injecting based of a 57% VE solid (his idle valve is also pegged at 50% pwm that entire time). If you're lean on a basemap, add fuel. Not through the deadtime. Just add freaking fuel to the freaking fuel map.

open the VE Idle table, highlight the damn thing, click the +, and add in an arbitrary value until you idle around 14.0:1.



I made a change to his idle valve settings that resulted in his high idle (moved the min duty from 30 to 50%)...something none of you open loop warriors know about because RTC likes to get random, unhelpful answers, instead of continuing communicating with the person who built his MS and setup his basemap, via email...

Has there been a resurgence in open loop idle usage ? I hope not

Open a menu/table.
Ask yourself: what does this do and why do I need it?
Find the answer.
Rinse and repeat for the rest of them.

Then ask yourself: what does my car need to idle? it needs controlled airflow and controlled fuel and spark. the spark is simple and already set in the base map, you can learn that part last. Learn the other 2. Apply this knowledge to the above questions/answers.

This is what's called: TUNING


or


Ignore this post and keep changing random crap in random order and get nowhere.

:bowrofl: it's only funny because of how true it is.

too lean? richen it up
idling too high? find out iacv settings by doing the iacv test and plug those in, that already should help bring it down. if it doesn't, then start messing with CL iacv settings.

Hi, I'm RTC and I have a confession to make: I forgot to make the change brain requested I changed the min idle valve duty to 1% (the max is at 100%).

I do not like getting random unhelpful answers. I just figured I'd annoy everyone instead of just making you feel special. Can't we all just get along? :ughug:

I sent you an email brain, but I have good news! Car idles at like 800 now! It was starting to lean out so I started adding fuel in the idle VE table.

The second I touch the throttle, the car leans out and dies. I tried adding a bunch of fuel to the other extended VE table, but it didn't help. The car runs a lot quieter now so I'm hoping to be able to do some ish tonight without worrying about waking up the neighbors.

Logs and tune attached. The shorter logs are from where the car wouldn't quite start up again after it died. Time to play with accel enrichment I think!

Edit:
On file 31.00: Things start happening after record 4300. Things start going lean. Looking at logviewer with the VE table present, it looks like it goes lean between 500-800 rpm all the way to the left of the VE table. This is followed by a failed start.

On 46.38: Failed starts followed by a start at record 1200ish. AFR oscillation at 2500ish start since I think I'm changing VE here. Then at 3300, I give it a tiny bit of gas and it dies. (or I try to give it gas to save it and it still dies). That's the limit of my current understanding, but I think it may have to do with table switching.

https://cimg5.ibsrv.net/gimg/www.mia...f5f4c27b77.jpg

https://cimg8.ibsrv.net/gimg/www.mia...99d10c747a.jpg