1992 Turbo 1.6 won't start after upgrading from MSPNP to MSPNP2
 

FWIW I've tried to provide all the information possible which has resulted in lots of words, but hopefully less flaming from critical omissions. I really appreciate any help I can get with this and would like to thank everybody in advance. Here it goes...

I purchased a 1992 turbocharged miata a while back that barely ran. After fiddling with it for quite some time, I took it to RPPerformance at Summit Point where they looked it over, said the engine seemed tired with low compression on one of the cylinders, but mechanically decent. They put it on the dyno and got it running through tuning, but didn't have time to dial it in. The car had a hard time starting when cold and had terrible off-idle acceleration and bucked on gear changes.

I looked around a bit to see if it was something I could fix, but ultimately decided to speak with the remote tuner who helped with my other MS3 car. He suggested we upgrade the MSPNP with an MS2 chip for better cold start settings and fuel resolution. I sent him the ECU and he upgraded the chip/firmware and sent back. I reinstalled the ECU in the car and now we can't get it running. It cranks and cranks, but doesn't fire. I feel like it must be a tune issue since it ran with the MSPNP just needed to be dialed in. I haven't mechanically touched the car so everything (timing/etc..) should be the same. I'm far from proficient at tuning and hoping somebody can take a quick look and see if anything is obviously wrong. My remote tuner did a great job on the MS3/VVT swap car and I'm sure he can dial in the tune once the car is running, but I need to get it started.

I've tried Miata 99-00 and 4G63 spark settings. I've attached the tune for each along with a data log of the car cranking for each.

Vehicle specs, relevant and not...
-1992 Miata 1.6L
-5spd manual so no variable TPS
-MSPNP2 (MSPNP upgraded to MSPNP2)
-BEGi-S turbo kit with GT2554
-LC-1 kit from BEGi
-stainless lines from BEGi
-ebay intercooler kit, it's cheap and needs to be upgraded...
-FM Clutch/Flywheel Happy Meal Level 1
-not sure what size injectors, whatever came with the turbo kit I imagine, but will check if somebody can tell me what to look for
-original CAS and coil pack on back of head aka not COP
-new NGK wires and spark plugs
-oversized aluminum radiator
-full Tokico adjustable setup
-Torsion full swap, not sure which one
-double diagonal bar with welded in harness bar
-frog door bars
-2002 Sport brake complete conversion
-TR Motorsport C1 wheels with 205 tires
-gutted interior, previous owner went a little too far and took out dash...

If I've left anything out please ask. I've tried to include relevant details about the situation and car, but may have missed something. I've also posted on m.net in case somebody sees the same thing over there. Thanks in advance!!

you just pugged a MS2 daughterboard into a MSPNP1?

Not sure since I shipped it off for the update, but he indicated it would be a chip upgrade. I sent a picture of the opened MSPNP1 to ensure there would be enough space for the new chip then I sent it to him. He installed the new chip and updated the firmware then sent it back and I reinstalled it in the car.

there are other board modications once must perform going from MS1 to MS2.

I can remove the ECU, take the case off, and upload a picture if that would help? The person I worked with builds MS units and seemed pretty confident/comfortable with it and said he had done it before, but I don't know enough to say what he did or if it was the right thing. Let me know if taking a picture of anything would help identify what was done and I can definitely do that.

do that.

the main crank trigger input needed it's polarty reveresed, and then the spark outputs have to be swapped and A to B (this you might have to do at your coilpack).


I'm assuming you're no longer seeing RPMs at all in Tuner Studio during cranking?

Yep you're dead on, no RPMs at all in Tuner Studio during cranking. I'll pull the ECU, take pics, and post them shortly. Thanks for the help with this!

Here are the pics. Let me know if there's something in particular you want to see that I missed.

Also weirdly, it was originally set to Basic Trigger and we were seeing RPM, but all other settings since don't show RPMs.

I need to see under that ribbon at D1 and D2.

so here's what i think you have going on now (you would have to confirm):

https://www.miataturbo.net/attachmen...ine=1461780845


You need to reverse the polarity of this input. So when I upgrade a MS1 to MS2, I do this:


https://www.miataturbo.net/attachmen...ine=1461780845




So I'm thinking: Remove the 2-3 Jumper at J1 and Remove the D2 Jumper. The pull-up should still be in place; but you'd have to confirm how it's done on your board.

That should be it. You should get tach signal back using the 4G63 trigger wheel in your settings.


Spark A and Spark B are now reversed from before, so you'll wanna swap your coil pairs around on the coilpack:

https://www.miataturbo.net/attachmen...ine=1461780845


@Matt Cramer or @Ben should be able to confirm this.

I removed the ribbon cable and took more photos. Here is what I see at J1, JP1, D1, and D2. I don't see the 2-3 jumper at J1, but I see it at JP1 which is I think what you meant. Is that what I should remove or am I confusing this? For the coil pair swap, do I just remove the coil pack and physically swap the two coil pairs or do I need to rewire anything?

you can physically swap the wires from the one pack to the other.


Yeah I meant JP1 but I'd see if Ben or Matt chime in to confirm stuff. looks like X1 and X2 are jumped and D1 and D2 still in place, so I'd have to see what they recommend as I dont know exactly how they've done the input circuit.

Sounds good, I sent each of them a PM so hopefully they have a chance to chime in. Thanks again for all the help with this and hopefully we can get it running soon.

I see the jumpers at J1 and JP1, which need to be changed, were not.

There are additional jumpers under the PCB that need to be changed and I can't tell if that has been done. If you don't want to pull out the whole PCB, carefully pull out the MS2 daughter card and get a picture of what is under that; there are often some clear giveaways about how the jumpers have been done there.

Here are top/bottom pictures of the daughterboard.

Here are bottom pictures of the PCB.

Sure enough, he just dropped in an MS2 daughtercard and didn't change the jumpers. Here is a spreadsheet of what jumpers should be changed.

Awesome, thanks Matt! Just to be clear, do I remove the stuff that's currently there? For instance, you put JP1 1-2 and I have JP1 2-3 right now, so I remove the 2-3?

Also, you listed JP 5-6, I need to check the board again, but I don't remember seeing JP. Did you mean J1 5-6 and if so, do I remove the J1 1-2?

Thanks a ton for the help with this!!

Correct, remove the other jumpers if they conflict with this.
That should be J1 from 5-6, sorry. J1's 1-2 jumper is removed.

i ALMOST suggested to just use the VR input circuit. I'm not well versed in how you guys did the MSPNP1 input (been SOOOOOOOOOOO long since I've touched one) I'm glad I had him reach out. Thanks matt.