Long story short, I blew the engine in my turbo RX-8, after a lot of consideration, evaluation, etc, I decided to revert back to N/A. I bought my car with the turbo kit on it, and it included a Mazsport Int-X.

I get everything put back together, new engine, etc in it, and it will start, but it won't stay started. I wasn't completely sure how the Int-X work, so I figured I would get the PCM reflashed by Mazda. They reported that after hooking up the PCM, they are unable to communicate with it and cannot help me out.

Does anybody know what's going on? Were modifications neccesary in order to add an Int-X (and are there any special steps neccesary to remove it)? I don't see any reason why I should need a new PCM, but that's what Mazda is telling me. I certainly don't want to shell out close to a grand for a new PCM

 

Removing the INT-x is as simple as unhooking the power and ground and then removing the factory ECU wires fromt the INT-X and plugging them back into the stock ECU. WHALA!!! INT-x removed and running of the stock PCM

 

Did you go back to the stock injectors? You likely had different ones...and if you had low impedance ones in any position..... that isn't good for your stock ECU

If everything is back to stock..you should be able to start..run and have no problems after removing the INTx

Also check your MAF...it hasn't been used for anything important for a bit...if it is crapped up the car won't run without it

 

If the ECU was "bad" the car wouldn't run properly with the INTx either

The INTx uses the stock DBW throttle..that means the ECU needs to be functional

I doubt that Mazsport had anything directly to do with it?? Idaho is a long way from Florida

There are lots of reasons for the problem...you are going to have to find someone that knows whats up to fix it. After bricking an ECU...the dealer tends to be the last place that can figure it out

You could buy a used ECU..as long as its the same as yours....you can have it rebuilt with "as built" data..and have your keys re-programmed...cost me about $300 and a couple of hours getting the tech to follow the directions properly so it would work

There are a few places that might be able to have a look at the ECU and re-write the ROM if that is the only problem Cobb is one of them.....Might want to give Them a call

 

Ok, clueless commentary deleted ....

 

Dannobre - I went back to a stock injector setup; my high flow injectors (not sure if they're low impedance... I didn't install) are NOT on the car. I'm going to check for vacuum leaks; after some other advice I'm suspicious that the vacuum line that goes to the spot on bottom of the intake manifold, just behind the throttle body never had anything plugged into it after the work I've done recently. That could kill the car pretty quickly; no air going through the MAF, but there IS air going into the intake manifold from that spot. MAF reads no air, so it cuts fuel... car dies.

Say what you will about how poor Microtech may be to work with - and I admit it had its problems - but it was an incredibly powerful tool, with so much to modify unlike a lot of other systems I've seen some people use on other cars. I was forced to learn a lot, and when I was tuning I felt more in control - good or bad. From that aspect, I'll definitely miss the system.

*Edit: And yes, this was a Mazsport tuned car. Semi-similar to their stage 3 top mount turbo kit, but with a lot of other stuff that the previous owner already had installed. I bought it from the east coast and had it shipped out here to Idaho.

 

Your MAF should read something even with a huge vac leak...so figure out why it isn't working

Check the sensor..and the wiring

I think that once you are getting MA|F values your ECU will be a lot happier

I don't have beefs with the INTx...it was a great unit when it came out. At that time there were no other options that worked well. It is a little granular..and very low powered compared to new EFI systems...or with the flashed stock ECU...but it does work if you live in an area that has small changes in ambient conditions..or you don't mind pissing with the tune