Help me plan my VVT swap steps into a 90' miata

So I've been through this thread (https://www.miataturbo.net/engine-performance-56/definitive-vvt-swap-into-90-97-chassis-megathread-80469/) 3 million times, but now that the TIME HAS COME. Here's the low down. I purchased a VVT motor that was in a 1990 car already (he's going to race in GLTC, so a k series was swapped in), VVT-controller, mspnp2, flyin' miata throttle cable bracket, fuel pressure regulator with return, and proper alternator. His setup diverged from the miataturbo guide in that he uses the na6 coils instead of the COP that come with the VVT motor. 

So my thought process is:
1) Swap the engine in with the stock ECU and see if I can get it idling? I know the TPS won't work on it, etc, but I think that it should work?
2) After getting it idling (probably badly) I'll then go through the MSPNP2  up.
3) I'll then get the VVT controller hooked up.

What's the fly in the ointment ? I'm skipping steps 1a-1z, etc - but I'm trying to have a car that starts and idles between each step to verify is my preferred approach. 

Here's some pictures because everyone loves pictures.

If you want to get it running on the stock ECU (not sure how well that is going to work), I'd probably try to add the VVTuner before adding the MSPNP. Fewer goalposts moved in that order, as you're not potentially chasing MSPNP2 and VVTuner issues at the same time.

In reply to BoxheadTim (Forum Supporter) :

The basis for trying to get it simply idling on the stock ECU is:

https://www.flyinmiata.com/support/instructions/misc/1.8swap.pdf

I **think** it should be able to at least idle if I hook up the majority of the sensors that will go the same way and get the injectors wired the correct way? The major one on the stock ECU is the TPS, and I figure I can just leave it plugged into the 1.6 TB short term? Though I suppose there's the issue of the MAF...

I've considered getting the ECU working on the 1.6 car alone, but I have major concerns about messing with the tune or setup when it has already been dyno tuned and matched......

In reply to accordionfolder :

I may have missed this then - the VVTuner and MSPNP2 came out of the car the engine came from?

In that case I definitely wouldn't try to get the MSPNP working with the current 1.6 and may even skip the part about trying to get it to idle on the original ECU, and keep that ECU around as a fall back.

In reply to BoxheadTim (Forum Supporter) :

Yeah - the full set of parts came from a very well running '90. It was a screaming deal. 

I debated this with my swap, and decided to go straight to running the VVT engine on MS.  In the long run, it's actually less work, though it may take you longer to get to the initial startup.  

Getting it up and running on the stock ECU just means you're going to do a lot of work twice.

Using the MS up front will allow you to check a lot of the sensor functions and test coils/injectors to confirm your wiring is working as expected before startup.  You can't really do this with the stock ECU.

Leave the VVT tuner until you have it running.

Your pics leave me a little confused... did you get a complete harness from MS to engine, or has it been cut (looks cut?)?  Was he using the MAF?  If so, I'd ditch that and run it SD.

In reply to Rodan :

This is where I'm thinking of landing.... maybe. 

The previous owner of the engine cut off large portions of the wiring harness to try and help me out I believe. The only "odd" thing I think I'm seeing is the fact that he's using na style coils instead of the VVT COP. His intake has a temperature sensor in it I believe. 

I see the IAT sensor in the intake, I was wondering what the taped up mess up towards the filter end was....?

A bit odd looking true, I'm pretty sure it's an "adapter" (i.e. the old plug) from the MAF to extract the wiring for the air temp sensor without splicing. I'll probably create smaller plug. 

I did something similar on my exocet before completely removing the plug from the system.

I modified/simplified the stock VVT engine harness into what I needed to connect to the MS and designed that to connect at the firewall.  MS sits inside passenger compartment, with matching harness through the firewall to that connection.

Engine side:

It took a little work to get the wiring done up front, but made things much easier from there on out.  You're going to want to check the run of every wire you're using and make sure you know exactly what wire is hooked to what...

In reply to Rodan :

Roger - that's what I was thinking of doing. I have a spare full NB and full NA wire harness and was hoping to make a fairly seemless patch harness. 

Are VVT engine's wired for sequential injection factory? That was another thing I did on the exocet that helped fuel usage. 

I honestly don't remember if they are sequential from the factory, but I know I wired mine up as sequential on the MS.

All 1.8 Miatas have sequential injection. Oddly, the 1993 CA cars do too.

If you want to break this down into steps, I'd probably start with the MSPNP. Get the car running with the 1.6, then swap out the engine. No extra work to speak of and it separates your ECU from your engine install. Then you bolt on the VVT tuner.

No worries about messing with the tune, just save a copy before you make any changes.

No advice. I'm just here to learn. 

Do carry on.

In reply to wheelsmithy (Joe-with-an-L) (Forum Supporter) :

Sweet, I'll do a full write-up in my build thread when I get it going. I hope to remember EXACTLY what I did this time. I've done so many complicated things on my exocet and can't even begin to remember how, what, or why I did things. 

In reply to Keith Tanner :

Got it! Thanks for the info.

I've totally messed up which tune went onto an ECU by misunderstanding the kind of cryptic messages from TunerStudio before. 

I'm waffling between "just do it all" and the ecu first option....

I know you can run a 1.8 tps on a 1.6 ecu by only hooking up the idle switch. I ran mine like that while messing with piggybacks and never noticed any difference from the missing wot switch. 

Keeping a notebook can really help.  I prefer pen/paper for jotting things down while working, and cheap 'composition books' from walmart work pretty well.

mmcvay said:

I know you can run a 1.8 tps on a 1.6 ecu by only hooking up the idle switch. I ran mine like that while messing with piggybacks and never noticed any difference from the missing wot switch. 

Note that the later (NB?) 1.8 throttle bodies didn't have an idle switch, they're a full pot IIRC. I believe the 1.6 WOT is only used to cut out the AC when the captain requests full steam ahead.

Still, you can run a car well enough to confirm full function without the 1.6 TPS hooked up. It'll only be weird at idle or closed throttle decel.

I'm in a somewhat similar situation.  I'm currently working on jamming a 2005 motor in a 1993 chassis.  MS3 and a turbo setup for good measure.   I figure I'll have it running by 2022z

In reply to KyAllroad (Jeremy) (Forum Supporter) :

Does the 93 run now? It's actually fairly easy to do the ecu install on the chassis motor. Learning the MS and tuner studio stuff is a bit of a task. 

Then you can deal with the motor swap stuff.

I.e. what I "want" to do, but I'm a bit scared of mucking with the settings since the ECU was set up for this engine.

Why not jump in with both feet? First step of swapping, removing the old lump.

 

In reply to accordionfolder :

It was running on the stock ECU when the motor let go.   So I pulled that and have been collecting parts and assembling the new motor before stuffing it back in the car.

In reply to KyAllroad (Jeremy) (Forum Supporter) :

Ah, bummer, then you're more or less in the same boat as me. Still not too bad last time I did it - and that included rebuilding part of the wiring harness. Let's hope this time goes that smoothly.