Car doesn't start unless Idle Control is set to "None"
 

1990 1.6, 5-spd
Stock engine
Begi turbo kit, 10psi EWG
MSPNP2

Previous owner installed everything. I went over the whole car referencing the manuals for MSPNP and the Begi Kit, and everything is installed correctly. I've owned 4 other Miatas and a Mazdaspeed3, and this is my 1st turbo Miata. I familiarized myself with turbo systems as I started modifying my Speed3. I updated the firmware on the MS and flashed a base map then set up all the basic settings for sensors, engine size, req fuel etc. Tunerstudio is also updated and everything seems to be working in the program. The car is runs and drives in its current state. Idle is an issue.

Car starts with some light throttle and then stays running and idling when Idle Control is set to "None", but not when PWM is enabled. It also does not rev higher as it should during warm-up, it starts and idles down to ~950 immediately, which is where I set the idle screw on the throttle body, otherwise it would be revving around 1300. ISCV is plugged in and plumbed correctly. I've read through the idle settings in the MS manual but I seem to be missing something.

I have an idea.

Tell us what "car" this is, how long it has been running on MSPNP, post tune and log, go to Meet and Greet and introduce yourself and said car. Tell us what kind of experience you have, and what you have done so far to this car. Tell us if you have read any of the MS or TS manuals.

Actually, that's a lot of ideas.

Sit down and think about how little information has been given for people to use to help you. Then formulate a specific question, with some background information.

Sorry. I've updated the first post and will get to the meet and greet. I'll get the tune and log uploaded shortly. Thanks for the feedback.

Updated first post with msq.

Welcome. I'll be honest and tell you that I personally don't know much about MS2, or NA Miatas, with what is different EDIT: from MS3 and NB's.

I know that it is typical on early models to add a variable TPS to replace the On / Off one that came with the motor.

Much better information. I suspect you will get some assistance shortly.

Regarding Base Maps. I would suggest you get the correct one from trubokitty, as Brain has one for your Miata / MS2 combination. I'm not sure is his parenthetical is saying that he pins out the same as DIYAutotune, or the opposite.

Unfortunately the previous owner has stopped responding to email so I can't ask him. I know that the unit itself looks like the MSPNP2 without the stickers on top, so I'm assuming that's what it is and is using whatever pinout is standard.

I took pics of the unit and attached them. In TS it sees "MS2/Extra 3.4.2" and also says "PNP" at the end of that info line.

OK. I looked over your tune. Brain's tune is better in almost every way. There are so many errant items in your tune that I would not start with it.

Do you have an AFR meter? EDIT: I see you do from the M&G thread
Is it connected to your MS? If not, you cannot tune this car.
Do you have a variable TPS?

I would load Brain's tune. Then resize your ReqFuel (injector size) back to yours.
Since you will need to re-tune fuel, I would also switch to Incorporate AFR
Then you will need to extrapolate the VE table into boost. Use the X-Y arrow in the lower left of the VE table and re-do the MAP to go from 15 to 200 in reasonable steps. TS will then stretch your table.

Turn on Overboost Protection

Then you will still have to fine tune everything.

Start with verifying and setting base timing. Instructions are included in the Setting Up Manual available from MSEXTRA.

Take it slow. Do not blow your engine because you are not satisfied with idle.

EDIT2: By "Brain", I am referring to Trubokitty.com.

Also, if you want to see the differences between your tune and that tune, download it and do a File / "Compare Tune" in TS and point to it. TS will show you 13 pages of differences including inj behavior, MAT Corr, AFR targets, Barro Corr , and on and on.

Yes the wideband is connected to the MS.

I believe it has a variable TPS? It looks like it has a Bosch sensor from various BMW models hooked up. And I can see all values of throttle position in TS just fine.

What about the pinout issue that Brain mentioned on his page? How do I know if it is configured correctly? Thanks for the help btw.

I can't look right now, but I think the pin assignments can be checked in tuner studio. Load one tune, look, I think under Advanced Engine for the assignments. Write them down. Then load the other (you can do so not in your project) and compare.

I cannot get to my computer right now. Might be Sun night before I can.

If the above does not get you satisfaction, I will page Braineack for you. Also, you could make a note of all the differences, and then adjust your tune accordingly.

Again, still realize you still end up with a base tune, which should get you running, but will not be job done.

I just went through both tunes side by side on different computers and updated my current tune to match all of Brain's settings minus the menus that I don't have access to. I will upload the new tune and see how the car behaves tomorrow.

One further word of caution. I'm only addressing likely tuning issues. If your MS build is bad, or wiring or physical build is incorrect, I'm not aware. I trust you that the build is right.
It sounds like you went over that pretty well.

I also assume that wiring splices are properly crimped or soldered.

Hope it goes well. Report back.

Ok so I uploaded all the changes, car started and struggled to keep running. Really shaky and super low RPMs. Also tried multiple different idle control settings, I think it only kept running when set to On/Off valve. I took a log of this that is attached.
I bought a digital timing light but was unable to get a good reading due to the RPMs jumping around. I took out the #1 plug and verified that TDC was marked correctly on the crank pulley by using the long screwdriver method to find TDC, lined up perfectly.
Car also ran pretty well when I bought it and I never touched the CAS. It still lines up with the POs markings.
Plugs were black so I replaced them with a new set of NGK I had bought for a Miata I owned previously. I have not attempted to start the car again after doing those 2 things.<

EDIT:
I just went back to the car but this time I reverted my ignition options and ignition table back to what they were when the car was running well. Car started and ran pretty smooth with an idle of about 1300. While running this way I managed to use the timing light and the marking on the crank pulley was landing exactly on "T" with the timing light set to 8 degrees. However maybe 1 minute into running the car then stumbled back down to the shaky low RPM idle that I captured in the logs.

Do you understand that the procedure to set timing is to go to Fixed Advance @ 10 degrees, and then use the Wizzard to adjust the MS offset until the physical timing matches the fixed 10*?

Yup. So I made some progress today. I got the car started with fixed timing at 10 degrees. Then with the timing light set to 10 degrees, a trigger value of -20.00 got my timing mark landing right on the 10 degree indicator on the timing cover. Burned that new angle and set the timing back to Map based.

Started the car back up after it was warm and found it was nearly stalling. Very rich. I started subtracting fuel from the cells it was idling in and improved greatly. The only issue right now is that to achieve the AFRs that I want at Idle, the RPMs end up being too high.

Not sure how to proceed. My idle screw is all the way in. Idle control still set to On/Off valve. I've attached the most recent log I have.

I'm no expert on fancy timing lights, but that does not make sense to me.

Set MS to 10*. Set timing light to 0* offset. Adjust MS offset until light on pulley shows 10*. Now MS and car are equal. That is the goal.

OR, set MS and light both to 10*. Adjust offset until light shows 0* on pulley. That is how I understand a set-able timing light works.

Seems to me that you are at 20* when MS is calling for 10*.

That may be why idle is so fast.

Also, why On/Off on idle valve.
What you should do is set timing. Then leave it fixed at you nominal idle advance, somewhere between 10 and 15*. Then used fixed idle control to find your max and min %. Those values are then part of the Closed Loop control.

You were right about the timing light. I fixed it. I'm now showing exactly 10* on the pulley with MS set to 10* fixed and the timing light at 0*.

While the car was running at fixed timing I used the idle valve test and found my min/max duty %. Plugged those into all the OL and CL fields where needed and the car idled well, hit all my targets.

However between cranking and closed loop kicking in, the engine struggles a tad, almost like the valve isn't opening fast enough or maybe there is another issue?

Also when letting off the throttle it doesn't settle back into that CL idle target in a smooth fashion, it dips a little. Same applies in between shifts. My latest msq is attached. I appreciate the help thus far.

So you can go back to CL Idle, I would imagine.

Now you have to tune things like CL target table, ASE, such things as that. You will also need to run VEAL Megalog tuning to get your VE table right.

Start at low kPa and work your way up. If, say, when you are 100 kPa and have to add a lot of fuel, be proactive and add fuel up through your 180kPa so that VEAL is removing fuel, not adding it.

Also, before you go to a dyno and fine tune the ignition table (if you choose to), set latency as needed (which you probably don't need).

Try to understand what each thing does.

A few, like setting idle valve min / max, Base timing is you telling MS what the engine wants. VE table and Ig table is MS telling the engine what to do. Other things, like EAE is a combination of finding what your engine is actually doing, and accommodating that in the MS tune.

Understanding which is which will help you treat it correctly.

Play (work) a while and when you cannot solve a particular issue, post back a tune, log, and a specific question. Otherwise, you seem headed in the right direction and now the fine tuning is set-up specific.

I went back to work on the car today. Still having issues with starts. Almost like its choking for a few seconds, then oscillation, then a somewhat stable idle. I was reading that it would be best to get open loop working properly before I can get closed loop working well so I went back to that.

I can't look at stuff until tomorrow. However, there are tests you can run to make sure inj are operating (while fuel pump is turned off) as well as if plugs are firing. Look in the test section. Fuel pump you should be able to hear if it is coming on.