I have a 1990 Miata with MP62 and 1.8 swap upcomming. I'm considering ditching the CARB legal powercard for a Megasquirt. I mainly just want that CARB legal sticker!
I need to dial in a couple details about how to do the engine swap and get EFI working. And know what minor wiring changes I need to make to the factory harness.
My car will be a stock 1990 getting a 1995 1.8 engine and MP62 Supercharger. I have a couple of options to run the engine. I have both 1.6 and 1.8 Computer Engine Control Diagrams, and I've been studying them.
1.6 Coils or 1.8 Coils
I could go either way here. Running 1.8 coils saves me from having to adapt 1.6 coils to the 1.8 head, but if the ignitor bypass is complicated, or there is a major difference in ECU or MS wiring, I can go either way.
(with 1.6 ISV and 1.6 TPS) or 1.8 TB
(with 1.8 ISV and 1.8 TPS)
I wold prefer to run the 1.8 TB with ISV and TPS because it saves me money and hassle of installing adapter plates to make the 1.6 TB to the 1.8 Intake Manifold.
The 1.8 CAS is on the exhaust side of the head so I'm using the 1.8 CAS with my 1.6 wiring extended.
The Stock ECU has no problem with this, so I imagine MS would not care either.
My 1990 obviously does not have sequential FI. But I can can add it.
No EGR to deal with.
The 1.8 Diagram does show an EGR function sensor. I dont think I care about it.
There are other differences between the 1.6 and 1.8 EFI systems, but I dont think I care.
Oh! The coolant temp sensor and fans. Yeah, I have to deal with that. Hopefully I can do it with just ONE sensor to make a coolant reroute easier.
I would appreciate any suggestions, tips, advice any of you have. So if there is anything that I'm not thinking of, such as "use XXX coils" or "do XYZ", I'm open to it. I do have to keep this as stock looking as possible because of CARB and SMOG police, but I don't mind making minor changes every couple of years.