MS3 Cutoff With no Gas
 

Good morning guys! I recently bought a MS3 from a friend that was fully configured. I have the MAP hose going to the intake, taking the spot of the Cruise control hose. I have not applied the turbo yet to my car, as I want to get the Megasquirt in and tune to get a feel for it... however, upon switching out the stock ECU for the MS3, it initially turned on but would cut off if I stopped giving it gas. It seems like it didn't have enough fuel going in unless cranking the gas. I did it a few more times but it kept cutting off (and killed the battery so I had to jump it). My buddy said that it was configured for a car that had much bigger injectors, and since my car had stock injectors, since it wasn't having enough fuel it was cutting off... so I thought "okay that makes sense" so I bought bigger injectors that will be here today.. since I need them anyway and what could it hurt.

I tried the MS3 again last weekend to try and get a log, but the car wouldn't start and the MS didn't turn on... I hope the fact that the car died 3-4 times when starting it didn't cause the ECU to bust... I'm new to all of this.

I am going to install the injectors Saturday and see if the car will turn on. Any input would be greatly appreciated :)

By the way, I have a 1990 Miata with a 1.6 engine. Only drivetrain mods has been a RacingBeat Cold Air intake.

change the req_fuel to 13.

start tuning.

You need to tune your ECU.

This.
If it's not tuned on YOUR car, it's not tuned. Period.

Wow thanks for all of the input and so quickly! I can tune the ECU without the car being on, correct? I had the ECU hooked up to a laptop but wasn't getting any readings from it.. which is why I though I may have blew it up.. although from a computer standpoint, that isn't really logical.

I should be able to hook up TunerStudio, put the car in Acc, and start tuning... I would assume? When I tried that before, no lights came on on the ECU unit.

https://www.miataturbo.net/attachmen...ine=1430409699

https://boswelling.files.wordpress.c...-out.gif?w=584

I am sorry if that was a stupid question... I would think that the car on Acc or On, would draw power from the batter thus turning it on allowing tuning to be possible. Since when the ECU did turn on, it only had the power lights on when the car was started, I didn't think it was to out there of a question to make sure it would or wouldn't turn on when the rest of the car drawls power.

You need to properly set up your ECU to match your car (hint: injectors) before you can start tuning.

Basically before we can even help you, you need to learn at least the very VERY basic knowledge about ecu's, tuning them, etc. We try to help as much as possible, but when you're so clueless that you're asking the questions that you are, it's kinda hard.

It's like someone telling you: fix your car by changing the oil.

And you respond with: "what is a car? and what is oil?"

Good luck