Replaced Supra ecu. Now emits dense white smoke?Mass Airflow? ECU reprogram req?
 

He’s baaaaaack, hopefully one last time; because so close and yet so far. I am posting this 3:00 pm. Friday Central Time, in the hope someone can get back to me while I continue to research online. After 3 months have finally found a replacement ECU to fit my ’93 Supra (nonturbo, auto trans., fed emissions) that restored operation of fuel pump and fuel pump relay. Original and first salvaged replacement we tried -- from a ’93 Lexus sc300 that is, by all accounts, interchangeable for Supra (although Lexus not Supra part #) had that same irrepairable/non-rebuildable fuel pump problem.

This current ( 2nd) replacement, identical to the prior Lexus sc300 replacement, works the fuel pump fine. However, vehicle now emits a dense white smoke (that burns your eyes) indicative of a fuel mixture problem, and that mass airflow sensor is not providing enough air to the mix. (Could it be that, with no working fuel pump, the first replacement just never got to a point where it would emit the smoke?)

Am I correct assuming the problem is not with the airflow sensor itself and we don’t just have to find a ’93 Lexus mass airflow sensor – but, more likely, that the new Lexus ecu has to be reprogrammed (“flashed?) to provide the correct info. to the air flow sensor for proper mix? Is it possible that the exchange from Lexus to Supra means that other variable calibrations on the ecu, like intake air temp. etc., would also have to be reprogrammed for the Supra? (This replacement module is likely direct from salvage and has never been reprogrammed).

If it is a reprogramming problem, I know there is software to take calibrations that will be entered into a tuner, but that also requires a certain expertise. If that is the case, should I be able to find someplace locally that can reprogram the ecu at lower cost than shipping the whole thing off to a rebuild and return place? If there is, would I need to find a way to get the car to that shop to take the initial calibrations, or could they take the calibrations directly off of the original Supra ecu that I still also have?
Thanks for any advice you can offer.

Roger Burke, Dallas Tel. (972) 980-2522 reb1000@sbcglobal.net

The white smoke could also be a damaged piston...I'd suggest a compression check? You'd think oil would burn blue, but I've seen this too many times, unfortunately...the bad smoke is very white.

If you want to pursue the overly-rich angle, you could obtain a fuel controller (eg. an old A'PEXi S-AFC, or the equivalent)...this will let you dynamically modify the signal between your MAF and your ecu (+/- %).

The neverending saga
 

Thanks, I’m holding the fuel controller thought for when our mechanic returns to town in two weeks (99% certain it wasn’t this issue that cause the guy to flee.) In the meantime, understanding when changing out an ecu, the new one has to be programmed to the calibrations of the vehicle where it’s being installed. Since the two I have were from salvage, neither one was. Found a number of local ecu programmers who informed that the ecus I have couldn’t be reprogrammed because either they, the car, or both are too old.

There are a lot of places that provide rebuilt units that are programmed for your vehicle with the information you supply There’s guy on the west coast who says he can do that for ours. But if both unprogrammable ecus I have are the right year for the 93 Supra, I don’t really see how any he’d have out there, that would have to be the same year, would be programmable either. Now at least I know the white smoke doesn’t mean somebody picked a new Pope. :)

The good news is I’ve now got a completely separate insurrection of kitchen appliances that have just jumped in to fill the void during the vehicular hiatus.

Nice - ROFL! :bigthumb:

Just a random thought - possibly irrelevant: You should be able to pick up an AEM gen-1 or gen-2 plug-and-play for the Mkiv Supra Turbo for a reasonable price (especially gen-1)...and there are hundreds of available-for-download AEM maps for the 2jz. Of course, the most important considerations when choosing map is turbo vs. n/a, and your injector size; next would be your choice of aftermarket turbo, and the last would be cams and/or head porting. Compression (pistons) of course would be important too, but most applications (and therefore most AEM maps) suit the oem-ish range for compression (pistons).

Please keep us informed of your progress.

Just curious - any update? Still hoping it isn't the 'magic smoke' that makes it go, up until it gets released (then of course, there's no way to reverse the process, which is what makes that smoke so magical)...