hello boys!
So, i've installed a shiny ms3pro on my 91 1.6 na miata (N/A) only to LEARN about tuning cause i'm obsessed with it but for now my learning process is blocked by a huge problem...
here's what's up:
- installed the kit (LC-2 AFR, IAT, ECU).
- Loaded a base tune from megasquirtpnp website.
- dialed in the timing with a timing light
- tuned a basic cold start (using open-loop) cause here in italy its cold af
- tuned a primitive (rich) AFR and fuel VE table
- tuned the accel. enrich to use the map instead of the TPS (cause my miata got the old tps wich is just on-off and not variable)

BUT THE ENGINE RUNS LIKE SH*T!!!

the engine shakes, A LOT! It almost seems like it doesn't burn well and it sounds terrible!
Doing even just a quick trip around the neighborhood has become impossible, the car jerks, wobbles and is much less powerful.
i have the basemap ignition timing advance and from all the videos i've seen online, this map is a great starting point but not at all for me! (or at least i think so, if that's the problem)
i also thought about the fact that my pulley had slipped a few degrees but it seems difficult to me... also because my model has the longnose crank pulley...

I really don't know what causes this problem and i'm ranning out of ideas...


basemap ignition table

 

Post a log...

Tune + Log is the minimum you need to provide.

 

sorry, here's the Log.
Please consider that in this log i lowered the ignition timing at idle to 12° just for experimenting but it has the same problem no matter what changes i actually do. So after i did this log i reset the idle ignition to base map value.

 

I would also chime in and say that if you want to learn tuning, this is the best time to start. It's hard at first, but doing your own research and watching/reading everything you can is going to be the best way to learn. Other people can tell you what's wrong, but figuring it out on your own will teach you more (my opinion at least).

 

yes! you are absolutely right! I've tried a lot of things but i've reached a point where my knowledge can't figure how to fix this particular problem...
that's why i wrote here, to get some tips to improve the car and improve myself.

 

So you installed a VTPS and tps mount; and calibrated the sensor?

 

Nope, i still have the stock TPS wich is basically useless so i set up the accel. enrichment to use only the MAP

 

Since you don't mention it, I assume it ran well prior to installing the MS?

IOW, the MS installation is the problem, not something else on the engine/car?

 

yeah… with the stock ECU the car was running perfectly! As soon as i’ve put the MS, the engine started running like crap.
I’m also sure that i’ve installed everything correctly so i think it’s a tune problem

 

I'll try to take a look at this later today and see if I can find anything.

 

Thank you so much!

 

What do you consider to be a good AFR for cruising? Are you watching your gauge or reviewing your logs?
You said you tuned your fuel table. What was your process for tuning it?

 

Like i said, i've only tuned a primitive afr table (basically i took the basemap table and got some spots a little more rich), i didn't even got my car to do a proper cruise test cause the engine is running very bad even at idle (also if i try to rev it i can feel everything shake as hell).
When i did the quick neighbour lap i realised that it's impossible to drive in this actual state so for not harming the engine i've decided to sort this problem first.

BTW today i checked again my timing and it's on point. I also checked the timing mark (just to make sure that the pulley didn't fail) on the pulley finding the TDC with a stick on piston 1 and the mark is perfectly alligned with the T.

 

I realize that. You said you tuned a fuel table. Does the fuel table make your car run at the desired AFR?

 

Yeah, kinda... at least for the idle i can get the afr that i desire, if i try to rev it up tho the car goes pretty lean. I've also noticed that i had to put pretty high numbers even to the idle area of the ve table to get it on point... the injector size and required fuel value looks legit to me tho (stock 1.6 inj are 230cc and the req fuel is bout 11.7).

 

So you tuned your fuel at idle it sounds like. Have you tuned it anywhere else in the map?
Based on your log you're driving around at 17-22 AFR, so I'm not surprised your car is struggling to run.

 

no i've just raised the table overall but that still gives me lean afr when i blip the trottle.
Do you thing it's "right" to have like 65 on the idle? is it a little bit to high number just to get 15 afr (at idle)?

 

You need to tune your fuel table. If you're as eager to learn as your initial post suggests then that should be easy.

I'm not trying to be a jerk, hopefully it doesn't come across that way, but you said your ability to learn tuning was being blocked by this issue. This IS tuning. Your fuel table is one of the first things to dial in. There's a lot to learn. If you can get something like HPAs intro to tuning course it will be a great help. It's regularly on sale for $1 and would give you a good starting point.

 

Thank you a lot for the advice! I will check that for sure!

 

I loaded up your tune, and could not find anything in the Calibrate AFR Gauge pull down item.
You need to have values entered there for the readings from the wide band AFR gauge to have any effect on your ECU operation. Maybe they just don't load when I load up your tune?

The VE table looks lean, in the sense that you have a fairly high set of values around idle, but then they drop off a lot as you go to higher rpm and under load, except at the highest values of both.
You need to confirm your gauge readings on AFR and the data the ECU gives on AFR are in agreement.
Then if you had to bump VE table so much for idle, you should do that for the rest of NA region of the table too.

There are so many other things that could be checked, or could be out of whack it is hard to say what else to look at, but I would try those two things above first. And make sure anything you do is after it comes up to operating temp so none of the warm up functions are still on.
For example, with the adjustments you had to make for the TPS, maybe the accelerator enrichment function is not set well, so the engine stumbles and bumbles when you step on the throttle. And other options for trouble.