MegaSquirt2 Tune Review (running crazy rich)

[LiquidCMR]

Hi All,

 

Recently installed MS2 in my stock '82 280ZX turbo (car happens to be '76 280Z 2+2).

 

Hope some of you experts can take a look at the attached project/tune/log and let me know where I'm going wrong.   I have not driven the car...just trying to get the basics down.    In addition the stock stuff it has a GM IAT and Innovate Wideband 

 

In short, the car runs VERY rich (9-10.5 AFR) across the board and won't idle.    I have not touched the VE tables (I assume I can run the analysis and then import the new settings) but I wonder if I'm way too early be playing with tables...and something else "big" is not setup correctly that I'm missing.

 

General MS question:   With the wideband sensor working fine, why wouldn't MS automatically change fuel to achieve the 14.7 AFR set in Required Fuel?

 

Thanks for your help,

 

- Chuck

 

 

 

MyCar5_LiquidCMR.zip

[motomanmike]

Just first off, your KPA ranges on your map only go to 100 which is full throttle on an NA car.  Anything over 100kpa is boost and your car doesn't have that area of the map to work with so be careful.  Go into the FAQ's and find a map to copy the ranges from.  Cygnus has some really good maps in the FAQ, his spark map works great.  Also, MS doesn't auto adjust its fueling unless you program it to do so then it only will do it to the extent of your VE table and your AFR target table.  If the GEGO correction doesn't have enough authority to pull it into what target AFR your AFR map is becasue the VE is that far off it can only supplement the fueling not get it exact.  Tune the car with all auto enrichments off, then use them to fine tune areas of throttle lift or depression. 

Edited August 25, 2014 by motomanmike

[dexter72]

Ok, With just a quick check your VE Tables are all over the place. Both the VE Table 2's look way off. It may help also if you list the injector CC's your using and so on. Your timing maps are off too in the higher rpm sections but that won't cause a rich run. 36 degrees advace at 5,000rpm is to high.

 

Look in the map sharing sticky section, find a map that comes close to what parts you have in your engine. Look at the timing and fuel sections and you will see what i am talking about.  

[LiquidCMR]

Thanks for the assistance guys.    My injectors are stock (265 cc).   Looking at other tunes, I notice most have lower "required fuel" values than my 11.8....which, in turn cause their VE tables to be rich for my set up (right?).      Questions:  Does my required fuel calculation look correct (seems pretty straight forward)?      Anyone have a stock turbo VE Table with the same required fuel as me that I can try?  Am I close to being on the right path with this???      Thanks!   Chuck

[dexter72]

I did see someone has a required fuel of 11.2, turbo with stock turbo injectors, 2.4l engine though. You can adjust required fuel up/down some and see how the engine runs. I would still fix your VE tables, some of them are all over the place.

 

I would remove your Wideband until you can figure out the rich run issue, Sensor may get ruined with the extra fuel.

 

If your tuning to get the engine to idle/run better, have you set Megasquirt so it doesn't make adjustments while your tuning??.

[Metro]

The required fuel is the amount of fuel needed for a perfect burn. It will go up or down depending on the size of your injectors. You should set it to the correct amount for your injector size. Most people are running larger injectors, thus the number is lower. The req_fuel value is used as the base for all your fuel calculations. so you need to set it correctly now and then start tuning. Looking at screenshots of my old MS settings for a stock motor, you should have a required around 12.

 

Anyway, you just need to read and learn how to use MS. Then try and apply your knowledge and then come back here when you have difficulties. It sounds like you just fired it up without any knowledge of what you were doing.

 

http://www.msextra.com/doc/index.html

[LiquidCMR]

Once again, thanks all for the information and input.  

 

I've been reading up on MS for a while but it is a little different actually "doing it".

 

I started with a tune I downloaded from here and then modified for my setup.    I was amazed the car started the first time I tried it last week.  Tonight I will be changing my VE table (per the recommendations I received on this thread) and see where that takes me.  Looking forward to learning more and getting this baby running like a top.      

 

Thanks!

 

- Chuck

[motomanmike]

Good luck. It might be a good investment for you to buy the registered version of tunerstudio so you can take advantage of the realtime VE tuning. It really helps you get things in the ballpark. No tune from someone else is going to make your car run perfect.  MS is funny like that.  I've got a few ecu's laying around.  If I were to swap one in my car and flash the same tune its been running on for the past year, it wouldn't be right.  It would be kind of close but wouldn't run like it does currently.  Odd, its just how it is.

[skirkland1980]

This may sound like a stupid question but is the map sensor getting a good vacuum signal from the engine?

[LiquidCMR]

That is a GREAT Question...and one I've been investigating since last night.   Something must be wrong with my internal MAP sensor and/or a setting in my config is way off.   

 

More information:  My MAP/kPa readings are over 100 ALL the time and the car has no load (just revving the engine in neutral).    Please see attached log which shows the high kPa /Load / Boost.    Note:  I have a vacuum/boost gauge which shows plenty of "vacuum" while at idle.    

 

What should kPa be at idle?  Like 35?

 

I've searched and can't find a setting that would explain the extra 80+ in KPA

 

Any ideas what I messed up?   HELP!!!

 

 

Also, I took Mike's suggestion and purchased the registered version of tunerstudio.    Before I run the auto WUE or VEAL, I need to make sure this MAP issue is sorted out.

 

Thanks,

 

Chuck 

[NewZed]

The A in MAP is for Absolute.  That includes atmospheric.  Copied the sentence below from one of numerous web sites.

 

"The standard atmosphere (symbol: atm) is a unit of pressure and is defined as being equal to 101,325 Pa or 101.325 kPa.^[1][2]"

 

^{Source (I have no connection,it just looks authoritative) - https://www.princeton.edu/~achaney/tmve/wiki100k/docs/Atmospheric_pressure.html}

[AkRev]

Where did you run the vacuum line from the ms box? As in, where does it connect on the engine? 

It is odd that it has pressure, it makes me think you have it connected upstream from the throttle body. You would need it downstream from the throttle body, or in other words, connect to the intake manifold. 

Edited August 27, 2014 by AkRev

[NewZed]

Sorry, I misunderstood what you were saying.  Looks like you're only reading atmospheric.  No connection to intake vacuum.  good luck.

[LiquidCMR]

AkRev,

 

My recollection is that I did not give much thought as to which vac line to put a "T" in.  I must have used a TB line which as pressure....what fool I am!!   I will confirm this evening.

 

Thanks!

[Metro]

You have the wrong map sensor set. You should be using the MPX4250 and it's set to MPXH6400 - a 4 bar sensor. I suggest you reload the default MSQ for your version of MS2 and then change each setting by hand by comparing it to other tunes.

Edited August 27, 2014 by Metro

[LiquidCMR]

Metro,    Thanks for looking up what I had for the MAP Sensor....great catch!  

 

I will correct both MAP and Bar to be MPX4250 this evening and change Barometric Correction at Total Vacuum % and Rate% to "0" and then update my barometric correction curve to 100% across the board (per Tuner Studio instructions)  

 

I'll also double check the vac line, and take a closer look at all settings while comparing to other tunes I've downloaded over the last week.    

 

This is quite the learning curve.  Appreciate everyone patience.

 

- Chuck 

[motomanmike]

You'll get it, keep at it.