My 7mgte is throwing code 31, and dies as soon as the throttle is opened..the afm passes the only test of the AFM given in the book. it was running fine and then it ran out of fuel, and i reset the safc2 at the same time, now i cant get it running. i also cant seem to find clear instructions on the initial setup of the safc2, i know it runs on the karman sensor, but what else do i need to input into it?
engine cod 31 and engine wont rev
- Thread starter moejoe2008
- Start date
The test in the book is for the air temp sensor in the afm.
http://www.cygnusx1.net/Supra/TechTips/engine_error_codes.aspx
31 is afm or it's circuit.
http://www.cygnusx1.net/Supra/TechTips/engine_error_codes.aspx
31 is afm or it's circuit.
yes, i tested the resistance of the afm as described in the manual, and it was within range. the car will now start and idle fine, but if you give it gas it dies instantly. it will do this for a min or so and then the cel comes on with code 31 and it will then start and idle fine, and will rev up to about 3000 rpm before it falls on its face and dies. It runs better with the light on then with it off, i'm assuming it falls into some kind of limp mode when the code is active?
The mode is called Fail Safe and yes, that's exactly what's supposed to happen with code 31. You didn't state exactly what you checked but as hvyman pointed out it sounds like you only tested the air temp sensor and that has nothing to do with a 31.
negative, i tested the afm as outlined on page FI-96 of the tsrm. the resistance measured was correct for the ambient temp. http://www.turboninjas.com/mk3supra/1990/indiv/07_FI.pdf Would the be indicative of something else being incorrect, or would you think that the afm is still bad?
no positive. You tested the air temp sensor. That is not code 31. The air temp sensor is in the afm unit and has a seperate circuit and code.
sounds like your afm is bad which is usually the case.
sounds like your afm is bad which is usually the case.
Sigh. I tried. It's guys like you that make me question why I still bother with this place.
edit: beaten by hvyman...
edit: beaten by hvyman...
my apologies, the book that i have (haynes or chiltons i dont remember) listed what i did as a test for the afm, i failed to realize the sensors were combined. I have owned a supra for all of a week, i'm sorry i did not instantly know that what you meant, thank you for correcting me.
HAHA, gotta laugh for a min. JJ does this remind you of a certain thread I had awhile back?? 
Moe find another good AFM electronics, yours is failing. I had the same issue, except my thread about this exact same thing went on for about a million pages.
Moe find another good AFM electronics, yours is failing. I had the same issue, except my thread about this exact same thing went on for about a million pages.
It does remind me because you and this guy are cut from the same cloth. Think they know what they're doing, don't, and have trouble accepting it. You both get props for effort though...
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Well I have trouble accepting something if I don't understand it first. Other wise my brain is just left in confusion as it was in that case.
you did mention you reset the safc II
have you put in the right type of sensor setting after the reset? aka karman sensor.
by default it goes to map pressure sensor
have you put in the right type of sensor setting after the reset? aka karman sensor.
by default it goes to map pressure sensor
Yes I did set it back to karman, and that is when i first realized it wouldn't rev past 3 lol I was trying to set the knock correction(or whatever they call it). And you guys are right, I don't know crap about supras...... yet....... give me any MG, Triumph, Healey, Rambler, or Buell and I'm your guy, but these cars are lost on me still. And these piggyback systems throw me off entirely, I'm used to being able to plug my laptop directly into the ECM on the buells and change absolutely any value for fuel, timing, 02 sensor corrections, cold start up maps, fuel cut, rev limit, and anything else you can think of...
Which is why the more automated vehicles get the less it takes to be a "mechanic". Could also be why when you look at a test for an AFM that charts resistance versus temperature (not to mention a test using only two of five fully identified terminals) nothing odd jumps out at you.
Last i checked it still takes fuel and air to make power, and tires, wheels, a clutch, and brakes to help start and stop it. Thankfully there are helpful people more knowledgeable then myself to help me sort out the rest.... i read all 16 pages of suprafanatic's thread on the same subject, makes more sense now...