JimBob

Just switched from stock ecu to MSPNP2, before switching had no issues other than occasional misfire or two on below freezing cold starts, so I switched out the plugs to hopefully eliminate any potential problems when tuning. Since started tuning the car won’t start on MSM base map, only trubokitty base map with a good amount of throttle modulation. Since getting the car started it has been choppy almost like its cammed and sounds like a lawn mower when giving it some throttle. When we switched plugs again trying to diagnose the choppy idle we found that cylinder 1 and 3 were black while 2 and 4 looked healthy. I hope someone can help diagnose the problem.

Really hoping with not a hardware problem with the ecu because of it visually being apparent that the previous owner has had to open it up in the past.

I understand the tuning has a steep learning curve but every forum search and youtube video seems to make backward progress for my situation.

91 1.6 Miata naturally aspirated with MSM 2, AEM wide band, and air flow meter delete

Z_WAAAAAZ

Post your tune and a log of the engine cranking and starting if you can.

Pic of the plugs wouldn’t hurt either.

Welcome to the forum!

SimBa

Did you mean MS2 and not MSM? If you are indeed using a MazdaSpeed Miata (MSM) map then that would be an issue.

Like Z said, people can guess all day that you need more fuel, less fuel, more air, less air, timing, etc... but a datalog and the tune file are going to show what's actually going on.

JimBob

I have attached the current tune we are messing around with. I haven't taken a log yet but I will asap and attach here.
I did mean the MS2 and not the MSM.

JimBob

Here is the warmup log and the map that was used. This is basically an untouched trubokitty map, pretty much only calibrated the sensors for what I have. Id appreciate any advice, thank you.

SimBa

To cover the basics, did you check your base timing with a timing light?

You might try to add fuel to calm down the idle oscillations. I don't have experience with the 1.6, but I assume that without an Idle Air Control Valve (IACV) you're going to have a harder time tuning your idle.
The base map you pulled is for your year of car right?

Sorry for the basic questions, just wanted to check for the simple things.
I've had my car on a standalone for a year and am still learning new things to this day. It's a long road, but the initial things are the hardest.

JimBob

Yes timing was checked with a light. At first I thought the wideband was configured wrong in the software but it does match the readout on the gauge. I also have set the voltage ranges manually in the software. The car does have an idle control valve and it’s a 2 wire one. I didn’t think it had one but after visually confirming it and the idle control valve test function changing the RPMs when playing with it, it definitely has one. The base map is correct for this year.

Don’t apologize for basic questions I understand it is a first step in trouble shooting.

Thank you.

SimBa

I might not have loaded your tune into Tuner Studio (TS) properly, but it doesn't look like you have any idle control setup. If you do have an IACV installed, I would enable idle control and start adjusting the maps for warmup and cranking.
As you adjust that, you'll need to adjust the fuel in your VE table to compensate for the additional/removed air.

If you know the min/max values for the valve it will help a lot. I'm sure you could get some ballpark figures if you search around on here.

I have no idea why your plugs would foul that way though, and that's probably something that would be good to investigate. Does the injector wiring harness look like it has been modified at all? Just realized that's a dumb question. I would guess the ECU wouldn't need any modification to run sequential fuel injection, but the wiring harness in the engine bay would. Do you have photos of the ECU board and modifications you saw?

curly

iTrader: (25)

He does, just open loop, but for whatever reason it doesn't seem to be following the table. Jimbob, your EGO is trying to add 15% fuel, and still running a bit lean. I added 20% in the idle region. Try it and see if it helps.

Keep in mind 1.6s have 2 idle valves, an electronic one and coolant based one. Honestly the coolant based one works good enough to barely need the electronic one. I thought I was an idle tuning god until I realized the coolant one was doing 90% of my idle taper for me, that and the mechanical dash pot. Get rid of those two and you'll have more or less a 1.8 idle setup.

SimBa

Not to thread jack, but Curly, when you view someone elses tune do you setup a new project in tuner studio using the specific board layout that the tune is built for? Is there a quicker way to view a tune?
I think I selected a slightly wrong version of MS2 when opening the tune, which caused some of the data to get messed up.

Didn't know about the different idle valves on the 1.6. TIL

curly

iTrader: (25)

When you open the tune, click “temporary project”, seems to work for me.

curly

iTrader: (25)

Re-read OP’s original post, and looks like the idle problems are secondary to the plug problem. Definitely confirm it’s set up and wired for batch for your 1.6, unless you’ve modified your harness for sequential, or if the car was originally auto.

SimBa

Well I learned something today. I figured there was a more convenient way to do this. I just tried it and that works great. Thanks

JimBob

Thank you for helping me out with the provided map. But you are correct the primary issue is still the misfire on 1 and 3. I have number of coils set to "wasted spark", replaced HTs, plugs and ignition pack. Also re-seated injectors and wiring for injectors. None of that made any change with the misfiring. I checked the plugs after like a 30second cold start and the plugs on 1 and 3 were black again but 2 and 4 are healthy. Tried swapping the factory ECU back in and the car ran great with the same setup. So either there is some funky mod or something way over my head that I am missing. As far as I can tell the harness looks factory on ECU side and ignition pack side. How would the car previously being automatic change ignition? I did not swap it and previous owner said nothing about it being manual swapped.

My MSPNP2 was bought used, so to eliminate another variable I ordered another one new to test with. In the mean time is there anything else I can try or test for to see why 1 and 3 are misfiring? My buddies and I cannot think of anything else to try.

Also here is that 30sec log with your map that you provided. Not sure if you would be able to see anything but I figured I should attach anyway.

Thanks again.

curly

iTrader: (25)

Sequential refers to injectors, not ignition. Try the attached tune, it should fire wasted injection, it'll either run like a rich dream, or do the same thing, let me know.

SimBa

You said it looked like the ECU had been opened up by the PO, but did you open it up? Do you have any photos of anything that looks modified?

JimBob

Ran it and it seemed mostly the same. Nothing inside the ecu looks messed with.

JimBob

Same issue with new ecu, both of your maps and trubokitty map.

JimBob

FIXED IT!!1!11!1

Pins 2V and 2Y needed to be swapped, idle issue was AC idle up was stuck on.

thak