So there I was (one of those stories) driving along last night killing time until I had to go pick my wife up from class. I was cruising at 45-ish and I had the check engine light come on and the darn thing did not respond to my foot being on the gas pedal. I coasted over to the right and when I pushed in the clutch to stop the engine shut off.

I took a look around under the hood and realized that my EFI fuse was fried-deep fried. I think I had a 30 in there (it was unreadable, but kind of looked green) instead of a 15, which I realize isn't a good practice. I had to switch a couple in the past and forgot to change it back to a 15. I had a new pack of 25s amongst the random gear in the back of my car, so I replaced it. No joy on the start up, though.

So being the slick dude that I am, I had all my tools, TSRM and a little bit of other random gear-as mentioned previously-in the back of my car, to include a piece of wire-bingo. Code 51 it was. I don't remember everything that the TSRM listed that it could've been.

After I disconnected the battery once the car ran and I got a whole 1/4 mile down the road until the same thing happened, minus the fried fuse. I took another look around under the hood. I checked the EFI wiring, which I'd like to re-do anyway, TPS and other wiring and such and saw no problems. Just for the hell of it I disconnected the battery again and it ran. *Sidenote-I had my good buddy Vinnie pick up my wife and bring her my way, so I had a little time to work with.* I let it idle for nearly ten minutes and it seemed OK.

I decided to take a chance and drive back to my apartment and good ol' Vince rode back (on his R6) behind me just in case I needed help during the trip back. I made it back but now I want to figure out what caused that. I refuse to just keep driving it after something like that.

What I'd like to do is remove my S-AFC (it caused a code 24 a while ago), rewire my injectors, get a voltmeter and do all of the testing that the TSRM suggests and see if I come to a conclusion from there.

If any of you would like to take a stab at this, please be my guest. Input is very much appreciated.

This may delay the posting of my pictures, so please remain patient on those.

most likely that the car is not getting a proper read out from the s-afc to ecu causing the car to shut off. Like you said, check all the wiring on it and see if you notice some things that might not be right. Beside that, maybe the s-afc may be faulty or may be having a glitch in it or maybe someone might have tampered with it making it act up like it is now. Just check everything between the s-afc to ecu. let me know whats up.

Thanks for the input. I think what I might do is just take the S-AFC off and see how things go. I'm also probably going to borrow a volt meter from a friend to troubleshoot as the TSRM says to.

Thanks again.

*Update* Add a code 14 to that. Lets just say my Supra rode home on a flatbed tonight. I refuse to get mad and curse the car, though, as so many do. I know that none of these problems would have arisen if it hadn't been for my itch to upgrade it.

So I've got a buddy that works in aviation electronics-aka avionics-that is going to do his thing with my ECU wiring later this week. Once goes through there and makes everything nice and secure I will at least be able to eliminate loose wiring there being the cause. I'm sure I can get ahold of a volt meter by then, too, so we can check to make sure everything is putting out the proper voltage.

I hate...excuse me...loathe electrical sh*t. I can't stand working on that stuff.

don't worry, it gets to the best of us too, beside that once you get that done, try to reinstall the s-afc to it and see how it goes from there. I hope you didn't forget to record the setting that you had before you disconected it, the last thing you want is to redo all the time you had in the dyno all over again. Anyway, let me know whats up, I want to see how everything goes from there.

I think I'm going to hold off on the S-AFC. I've got a MAF-T that needs to be installed, so I'll at least be able to achieve a modest level of tune with that once I get around to using it. I'll try to do that at about the same time that my SP61GT goes on.

sounds like a good way to go, anyway, how did the wiring check out? I hope everything was straight with that and since now you got the maf-t, hopefully everything will work out fine from there.

Code 14 is often a bad ground at the coilpacks fyi. Code 51 has always been a mystery -- it usually is intermittent

yeah, that would definitely be the cause, but as you said, it is always a mystery. Also, the last time that has happened to me, all I did to correct the problem was replace the coil packs and also the igniter. After that, that resolved all the problems that I was having. Oh by the way, go to ebay, since its the holidays and all, I found you a microtech piggy-back for you if you want to go after that. I would get it for myself but I rather pass to someone that needs it more than me. For now I can do with the s-afc that I got for my swap which right now is gonna be done after new years. Let me know whats up.

Craig; try making a new ground strap for the coil pack chassis with at least 12ga and ring terminals. then, the other thing i can see going wrong w/ the Code 51, is something with the TPS circuit. Itll throw a code if there is no IDL signal. if your TPS is out of adjustment, the TPS will never go into the IDL position and tell the ECU that the throttle is closed and to revert to Idle parameters. the NSW signal could cause a problem, but thats only with Automatic cars, unless the clutch switches are faulty too? thats the only thing that could have been modified or compromised. the other aspect of a Code 51 is the AC amplifier, switch or circuit... and i doubt that anything pertaining to the AC electrical has been modified or compromised... UNLESS, youve had a leaky battery in the past. If battery acid or corrosion has sloshed off the battery and landed on the connectors below the underhood fuse box (like on my 89 turbo), then the AC magnetic clutch wire/connector could have been compromised and Might be grounding out or whatever. give that a look.