Matt Cramer had a peek at my tune and didn't scream in horror or laugh so I guess it's OK enough. VEAL keeps putting a weird "bump" in between 53 and 100kPa around 1000RPM that is causing an off-idle stumble but I can smooth that out manually. So, other than my sissy injectors, I think I'm good.

I should have the 650's in by mid-week next week and that should give me enough time to make things right - we'll see...

Installed the 650's today, reset REQ_FUEL and ran VEAL to pock in the changes. I still have a problem with stumbles at WOT even after fooling with the accel enrichment settings.

After a bit of reading here I've come to the conclusion that; a) I need to re-gap the plugs in case the're being blown out, and b) I have to check my overboost protection settings. I'll do that tomorrow and see if there's any difference.

Ain't tuning fun!

Plug gap?

If it's overboost, you'll know it. Trust me, it's like hitting a wall.

I'm not absolutely sure but I think my plugs are gapped to .040 or .035 - they're NGK plugs but I don't remember what heat range they are. Me thinks that might be a bit too large a gap and the spark is being blown out in high-boost situations. What it feels like is as if one or more cylinders isn't firing. The exhaust note goes flatulent (as in it sounds like a fart) and all forward progress stops until I back out of the throttle.

Isn't 11.5psi (or something like that) the default boost cut for the newer MegaSquirts? I feel like we have had more than one person get bit by that here on the forum. They end up chasing what they think is an ignition issue only to discover its overboost protection.

I wasn't blowing out spark until 16+psi @ .040. FWIW....

Well, well, well...it's a good thing that I checked my spark gaps because 3 out of four of my plugs had badly corroded ground electrodes! Yikes!! Seeing them, I wonder how the car started and ran at all.

Anyway, I put in some brand new plugs and gapped them to .030 (just in case). I also changed the overboost protection up to 12.5 psi (for now) with a hysteresis of 0.5 psi. I'm embarassed that I didn't check that earlier. So I'm back to VEAL-ing to get a better handle on the tune. Now it's time to figure out why the plugs got so weird in the first place.

Eroded electrodes are a common sign of detonation.

Beware.

I know...I'm scared...

I was using a VooDoo box before the MS and I'm sure that was a contributing factor. I knew I was treading on thin ice with that setup, but I went there anyway. Now that I see the error of my ways, I will tread carefully.

PS - the engine is coming apart in about 2 months. If it holds together until then I'll see just how much abuse I have heaped on it.

OK...time to put on my flame suit...

I've been searching all over and haven't found anything definitive about using the stock '99 knock sensor with a MSPNP2. This thread is as close as I've gotten, but the answer is tantalizingly out of reach.

Matt (if you're listening) says, "Make sure your project is set up for the Microsquirt Module", in order to get the Knock Sensor Setting dropdown to present a selection for "ADC2" as the input for the stock sensor and then...nothing! And I can't find another reference to the same thing anywhere.

Thoughts anyone?

Yeah, I don't use it and don't trust it.

Tune by ear with det cans if you want to tune it for safety. Short of that just use a base tune spark map and ensure your base timing is accurate.

"Today's adventure" is to tune the spark map.

So, I'm using the audio port on the PNP and listening to "Dem Sweet, Sweet Engine Sounds", trying to decipher what's coming through. (I think) I'm hearing detonation on high-ish load situations, so I've already backed down the timing on some affected cells. I need to get to a det-free condition, 'cause I'm going to the Evolution School this weekend and I don't want my engine fried while I'm there.

Oh joy...

Maybe I missed this but what is the temp range on your plugs? Are you located in Michigan? I don't have a ton of time but if you need a hand tuning (when the weather allows) I'll hop in the car with you.

I don't recommend using your knock sensor for tuning just yet. In fact the only time I really recommend using a knock sensor is to first make sure you have an absolutely knock free map and do a baseline reading through multiple gears, multiple loads. Then make sure you set up your knock sensor offsets accordingly. Even then, I still wouldn't use them to tune - just as a failsafe.

Just remember you'll see a loss in power gains before it will produce recognizable knock. And although I'm sure you've done this - Make sure you set your base timing. It sounds like you're learning quickly, just make sure you don't read something on the internet and then immediately start making changes to your tune. Things will get sloppy quickly :)

FAB - Thanks for the input. It's a steep learning curve but I think I'm making headway. It's like crossing the Rockies, you see a mountain that seems insurmountable and hunt around until you find a pass that'll get you through. Bu just when you think you've cleared the last hurdle...there's another insurmountable peak.

What I'm leaning mostly is that only the strong survive - and I intend to survive.

About the knock sensor...I'm not so much TUNING via the sensor, as I am trying to get to that knock-free spark map. I did an A-B comparison in the sounds between the default map and a more conservative one, and I can tell the differences! Now I'm trying to ferret out places where I don't have "happy sounds" and adjust accordingly.

One question to the "Einstein's" here on the board. In my searching for information here, I've seen MegaLog Viewer screen shots that show knock from individual cylinders. I'm running Viewer version 3.4.04 and I'm seeing no such thing. Maybe I'm just dense, but how can I get a display of the (stock) knock sensor signal? Or am I just SOL?

Forget the knock for now. I've got to get the accel enrich done. There's a bad stumble when I jump on the throttle and it's driving me crazy. I've been making changes to the AE settings, but have not made much progress. Now it's time to get more scientific with my approach.

I've read a bunch of threads but, between different versions of Tuner Studio and different setups. I've mostly managed to confuse myself. I need to understand what things change with the different settings then I can be more methodical.

Things are getting interesting!

I found this article on msextra.com that gave me some understanding of what the parameters in the AE window are doing. So I decided to turn off AE (by setting the TPSdot threshold very high) and turn VEAL back on so that I could have it do it's magic around the area of the table where I'm having so much trouble.

What I noticed was; a) VEAL wasn't making many significant changes to the table, and b) the drivability around idle tip-in and at moderate TPSdot values (200-250%/s) was significantly improved! I was hoping that "a" would be true (as I spent days running VEAL at as many conditions as I could manage so I was fairly confident with what it produced), but "b" was a real shock!

So tonight's adventure will be to re-introduce AE with some small Added ms values and see what happens. My approach will be to start with a horizontal line on the TPS-based AE graph, using small values and then slowly increase the Added ms (while trying to keep a constant TPSdot) until I get a stumble. Then increase the TPSdot and repeat.

Sound reasonable?

Step 1 - no more than a TPSdot of 100%/s (pretty moderate in my book), with a threshold of 50%/s and all Added ms set to 2.0 I get no stumble. Changing the Added ms to 3.0 and...ta-da, there's the stumble. So I set the first point to a TPSdot of 50 with an Added ms value of 2.0.

Step 2 (tomorrow) - gonna try a second point of 250 TPSdot and an Added ms of 3.0...methodical progression until I can get the TPS-based AE working like I want.

Hooray!!

I've got the TPSdot AE (seemingly) dialed in. The car is running great, and responds to the throttle - everything from light accels, all the way up to 900%/s WOT accels - and I'm a happy camper!

EXCEPT, that my next challenge is to solve a nagging hot-start problem. When the car warms up and is shut off, after a heat soak of about 10-15 minutes it will start - with a bit of coaxing from the throttle, and extended cranking - then the RPM's will go way low and if I don't catch it with the throttle it will die. I have to catch it and idle at 1500 RPM (or thereabouts) for a minute or two before it will keep a 900 RPM idle.

A bit of searching (both on the site, and in TS) led me to the MAT air density correction table. Based on what I saw in the threads I encountered, the "stock" settings in TS are a bit too extreme for a Miata. So, I'm going to play with this table until I can get a good hot-start.

After I get that solved...on to using "Incorporate AFRTarget"!

Nice work, I may be referencing here once I finally get around to installing my MS2

Agreed, props for working through the documentation and providing feedback. Not all of us are tuners and its great to be able to reference others experiences as well :bigtu: