Just a quick question, maybe for joe or brain.

If I want to run parallel on an NA miata, particularly the 89-93 with a 1.6L, so the stock ECU can take care of everything else, would I just need to remove the 5V pull up from the circuits?

 

you'd build it exactly as shown. but why parallel? the stock ecu only will control idle and the MS-II can control it better.

 

Thanks for the quick reply. Guess it isn't like the other circuits.

I got someone wanting to install MSII on his car but he doesnt want to deal with tuning idle because he has A/C and an original TPS. Going to try to convince him that it's not so bad and to get a working VTPS.

 

the PID idle code can handle the a/c activation fairly well. there will be an initial dip when its turned on, but it will recover and idle smooth.

I always found in parallel the oem ECU did weird things at certain AIT and CLT temps when idling.

 

Does this apply to both MSI and MSII?

 

i never tried ms1 standalone, but when ive run some MSPNP units on my car it was fine.