EGADS, tuning my megasquirt fi system, is driving me nervous.

If anybody has and would wiling to share tune files with me, I would be very appreciative. As that would allow me to compare it with mine

Thank you in advance

Using someone else MSQ file could potentially be a bigger headache than just setting yours up from scratch. The tune file contains more than just the fuel and timing maps but also contain all your base configuration information in addition to also specific to the ECU firmware of which there are very many variants.

You can load someone elses MSQ but unless every bit of your FI and engine hardware is identical it wont work properly out of the box.

I want to review them, primarily ve setting so I can make some sense out of mine

James is right, of course. Here's my .msq (attached), if you want to look at it for informational purposes. Major caveats:

1. I'm still fiddling with the tune quite a bit. My main remaining issue is cold start / cold idle. Still working on that.

2. This is for my build. It's a 2270, speed density, custom-injectors, etc.

3. Also, this is a Microsquirt file. Hope you can use it.

You may want to post specific questions if you're trying to learn how to make sense of VE tables and tuning. Tell us about your build, too.

Click to view attachment

I agree with James. Others have asked for mine but I'm not comfortable doing that; I'd feel really bad blowing up someone else's setup (or causing them even more troubleshooting grief).

However, I'm more than willing to converse with someone on my tuning procedures, and assisting in troubleshooting issues with theirs.

Here's my tune on my 1.7. It has a longer duration cam, CB independent throttle bodies, Triad exhaust, trigger wheel, and waisted spark. So it is just a reference but will probably not do you too much good. However the Base tune that was on the microsquirt when Mario sent it out to me had the car running and idling out of the box. Mario (The Dub Shop) was able to log in to my computer remotely and finalize the tune on the dyno for us. Great guy

Thanks for the tune file. I am running the dub shop setup with CB Performance ITB's and a MSDS header on a stock 1.8, building 2056 motor is next task on my list.

The base tune from mario, got me running, but it still has a long way to go.

I am puzzled about the ITB's and the Kpa, I seem to be idling at about 50kpa, does that sound right, per your experience.

Did you or Mario set the req fuel value to match your displacement?

Assuming Mario loaded some sort of base config on there and its not just the stock Megasquirt config, stick with the msq Mario had on there as he knows what he is doing as far as setting up all the base settings. He may even have a more accurate fuel and timing map for a stock 1.8 if you ask him.

Provided the req_fuel value was set properly the only part of the tune you should be tweaking at this point is the fuel map and possibly the timing map (depending on how Mario set those)

Importing timing and fuel maps is a safer way to go as they are independent of your specific hardware and the full MSQ file and good timing maps for type 4s are going to roughly all be similar.

Post your current timing and fuel maps and I could give you a rough idea if something is obviously out of whack. Other than that, if you have it started and idling you should be using your wideband sensor and autotune or datalogs to dial your fuel map in.

Do you have the mega log viewer? I just recently started looking into it and I think I'm going to buy it as it seems hugely helpful to fine tuning once you have a base tune in place.

What problems are you having? Learning to tune your system is sort of a prerequisite for having custom EFI.

Full registered versions of both Turner Studio and Megalog viewer are more than worth the price and absolutely invaluable for tuning the car yourself.

I'd instead call it a "benefit".

Poor choice of words. It is a prerequisite for having a well tuned car, however.

Yes, I am using the base map that Mario created.
She starts right up maybe 2 seconds of cranking, and I have gotten her to idle smoothly, albeit a little high, and have gotten the ITB's balanced, as far as air is concerned at idle.

To lower the idle, do I change the ve table, in the range that map is displaying, or do i change the fuel table. That is a little confusing.

I purchased the upgrade to TunerStudio and mega log viewer, but still getting used to reading exactly what is going on.

She seems to be running ok, but the throttle response is not what I expected, it eventually gets there, but it takes a while. Maybe I am thinking of it the same as my bike that was dyno tuned with a dynojet computer, the throttle response, is crisp, all you have to is twist the throttle slightly and it is off to the races.

Maybe I am thinking about it in the wrong way.

Also, I am planning on creating a log to send to Mario, so he can look at it.
What should I do, do I find a place where I can go thru the gears to redline (almost),

Tell us about your setup (maybe you've posted this elsewhere).
You say ITB's - which ones? How are you getting a vacuum signal?
Are you running alpha-N?

Check timing, because timing affects idle speed.

Once timing is set, if idle speed is not correct you need to adjust the air getting into the motor. How you do this depends on your setup. First, make sure air isn't getting into the system through leaks, warmup valves, etc. Then, set the ITBs. There might be air bleed screws - close those slightly. Or, you might need to adjust the stops for the butterflies. It depends on your setup.
Make sure the ITB's are balanced - this may require adjustments to the linkages, and you may need to readjust as you adjust the stops. You'll need a tuned ear or a synchrometer to make sure the ITBs are well balanced.

Once you have set air, check mixture - look at your wideband O2 gauge, either in your tuning software or maybe you have a physical gauge that you've added to the dash. Adjust fuel until you get the best idle. I'm used to working with the VE table because I have a MAP based system, but if you are running alpha-N it might be different.

You may need to go back and forth between air and fuel and advance a few times to sort of "walk" the motor into a good place in terms of idle speed and AFR. Target AFR depends on cam, ignition timing, etc so there isn't a specific target value, it is whatever the motor likes, but should probably be in the range of 12-14.7:1.

Fuel, air, spark - you have control over all of these things and it's a matter of finding what the motor likes at idle, gives best performance vs. load and is safe for the motor (not too rich, too lean, or too advanced).

I highly recommend an AFR gauge for the dash so you can keep an eye on things while you drive. It will tell you if you get into an unsafe/untuned area. You don't want to be driving around at full throttle and 18:1 AFR all the time.

Good info from Jeff. From what I've heard alpha-N may be the way to go with ITB's. I actually ran Alpha-N on mine for a while (it's a stock 2.0 throttle body/manifold), and it ran pretty well. I just didn't seem to be getting a strong enough vacuum at idle to make idle fine-tuning possible. This is related to my second comment...

...don't put TOO much stock in type 4 AFR readings at idle. You MAY get something useful, or you may not, depending on a number of factors. I was crazy rich when my AFR showed crazy lean, and that had me chasing my tail with VE values and other settings for a long time. My point is use other inputs besides AFR at idle to determine the best tune. I should have trusted my instincts earlier.

Yeah, tell us more about your setup.

Know what I use for tuning idle? The ole D-Jet idle hunt.

D-Jet fans will remember that the engine loves to hunt idle when it's to lean. It'll waiver between +/- 100-200 RPM when you get it too lean. That's when you reached over to dial the knob on the ECU a click or so to get it to stop hunting. Same thing happened when the CHT was telling the engine that it was warmed up when it actually wasn't warm enough: it would hunt idle for a bit until everything actually got nice a toasty.

So that's what I do for tuning. I'll continue to lean it out at various temps until it wants to hunt, then I'll richen it. Do that through the whole range and the car warms up and idles nicely. Usually results in the AFRs showing around 15 when fully warmed up.

Of course, mine is a stone-dead-stock engine. I have no idea what kind of action that'll result in when I rebuild it with more compression and a non-D-Jet cam. Do they still do hunt when modded?

Greg

This is true, if you have a cam with a lot of overlap your vacuum and AFR below a certain RPM will be unpredictable. I had a motor once with a hot cam that had very little vacuum below 2000 or 2500 RPM. It was difficult to get a good idle if I tuned by the numbers. The numbers might look "wrong" but if the motor idles and is otherwise happy you don't need to worry too much about it. It's just a matter of getting the motor to keep a steady idle, not bog down, not foul plugs. If the motor has a big cam it may never idle very well. My solution to this in the past has been to raise the idle speed and add advance at idle. Your motor might behave differently.

If you have ITB's and you are running alpha-N then you can safely throw vacuum out the window...

Fancy running into you over here as well as Facebook. (Guy with the converted Squarback needing seemingly different tunes for hwy and around town) I am fairly well baffled by cams, do you (or anyone else for that matter) think this would work with a Scat C25 in an otherwise stock 1.7l?