Code 31

[deabionni]

the AFM HOUSING and not the electronics right? There is no way to "clean" the AFM electronics. That is the sure fire way to kill the AFM electronics though!

There's no way to clean off the electronics inside the AFM housing? Great!

The guy I got the GTE from has a K&N filter hanging off the AFM housing, and I can see oil residue completely coating the inside of the AFM.

Once running, my first priority is getting rid of that K&N and getting a quality dry filter like an Apexi.

 

[figgie]

There's no way to clean off the electronics inside the AFM housing? Great!

The guy I got the GTE from has a K&N filter hanging off the AFM housing, and I can see oil residue completely coating the inside of the AFM.

Once running, my first priority is getting rid of that K&N and getting a quality dry filter like an Apexi.

The AFM electronics? Unfortunatly no.

The AFM housing by itself, yes.

Just remove the AFM electronics. That won't do anything though. The AFM, I have never seen one get "clogged". They usually die of electrical causes.

 

[deabionni]

Thanks, figgie, that's what I needed to know. So once the electronics don't test out, then they're dead, right?

Looks like I'm looking for a new one in the sale section.

EDIT: Is there any difference in the AFM between a pre '89 and post '89? I assume that any year of AFM will work, correct?

 

[figgie]

EDIT: Is there any difference in the AFM between a pre '89 and post '89? I assume that any year of AFM will work, correct?

correct.

 

[deabionni]

Thanks.

 

[supramang]

LOL, nope same old, same old. Im hoping the stand alone will be able to take care of it, hint for this winters project.

Supramang, sorry for taking your thread off topic, but again if you are in the area fell free to contact me and you can use my afm

Ha ha no problem! But yeah im down by Lakeville if you know where that is. So its quite a drive up there!!

 

[supramang]

On another note....... last night i drove with a bunch of guys to Red Wing for a high school football game and my car was doing its B.S. idle garbage with the check engine light on. It happened when the engine was cold too! On the way home it was much worse, it would not stay running at idle. But like usual it would go away as i drove down the road... WTF MATE!! I was hoping this would go away with the cool weather.

 

[92nsx]

Ha ha no problem! But yeah im down by Lakeville if you know where that is. So its quite a drive up there!!

Yep I know where you are I grew up in Owatonna, I know there were a few MKIII around there back in the day, but not sure any more.

 

[jetjock]

deabionni: If you're going to toss that AFM I'll take it off your hands. It'd be nice to have as a spare...

 

[supramang]

Yep I know where you are I grew up in Owatonna, I know there were a few MKIII around there back in the day, but not sure any more.

Ha ha yeah i dont think i would be in anyones memories from back in the day, im still pretty damn young compared to most guys on this site.... i think!

Owatonna ya say... they have a damn good cross country team!! Dont know if you know anything about that stuff ... its just that i run cross country lol!

 

[ccwade]

ks is the actual karman signal back to the ecu that tells it how much air is being read (then the ecu decides how much fuel to add). E1 is the ground for the afm meter and VC is the intial 5v power suplly that gives the afm power to work with (totally dead with out it).

pull the afm conector and with the key in the on postion (car off) put your volt meter test leads on E1 and VC, should be a solid 5v or around there.

plug the connector back in and strip some wire insulation back on the KS and E1 wires. you need to be able to read HZ. put your test leads across the two exsposed wires and with the car running at idle it should be around 15-20hz. it will increase with rpm so a cold idle will read higher then a warm idle. (my multimeter reads khz, move the decimal 3 to the right and you have your hz reading)


http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=FI&P=96



what finally fixed mine, so far, was pulling all the wires out of the afm connector and spray the hell out of it with carb/brake cleaner. make sure to remove the oval rubber gasket that sits down in it though! and make sure to mark each wire in relation to where it goes on the connector as you pull them out. i pulled 4 out with out paying attention and got a few mixed around.

I am getting codes 24 and 31. I changed out my air filter and saw that the AFM housing needed cleaning, so I proceeded to clean out the whole unit, but unfortunately I need not remove the AFM. So I got a used one off of ebay but the same thing happened. I then check all my hoses in the air system. I found that the Air cleaner hose, the one that goes from the turbo to the afm, had a big tear in it. So I replaced that one with a new one. I thought and hoped that would fix it. No such luck. Both AFM's produce the same results. Idles fine but upon acceleration, spits and sputters. I am going to do what you suggested. check the wires and clean them also, again.
Is it possible to have 2 bad AFM's? Is there anyway to get me one that has been tested on a car that runs good? I really am getting frusterated with this. I would appreciate any help or suggestions. I need to get my car running ASAP.

 

[grimreaper]

yes it is, and try a forum member as many have switched to other forums of tuning and no longer need the afm even though it works. The afm electronics is not to be cleaned, as you already found out.

you can leave it unpluged which puts the car in limp mode, nothing over 3000rpms iirc.
try a few junk yards near you and look for early 90's lex. The electronics are the same so buy what you can find.

 

[ccwade]

If the afm reads the correct hz, does that indicate the afm is okay? How do i test to see if the ecu is working properly? thanks

 

[grimreaper]

check the continuity of the connector to the ecu, and clean out the connector on the afm side. (plug on harness)

 

[ccwade]

how do i know for sure if the problem is the afm or the ecu? I haven't done the hz test because i don't have a multimeter that has that function, but I am going to go buy one today. I have a question on your directions for the hz test. you say to put your test leads across the two exsposed wires, do you mean put both leads of the multimeter bridging the exposed wires? If that reads the correct hz, then is the afm okay? what pins do i check continuity between the afm connector and the ecu? sorry for all the questions, but I have an excuse being a woman. thanks for the help.

 

[Flateric]

Have you checked your TPS lately. Drove me nuts but sounds sorta similar.

Fixed everything for me.

 

[grimreaper]

Put one lead on the ks signal and one on the e1 signal. then make sure the hz is good and increase rpm and it should rise accordingly.

Check all 5 wires at the AFM to ecu. Your testing that there is no break in the wires under the hood. You have to remove the glove box to get to it. Follow the TSRM pin out for the gte ecu so you know which wires are what on the ecu connector.

 

[ccwade]

Thanks for the replys. I am not for sure what the tps is. I checked the hz range per your instructions, it was all over the place. 100hz up to 600hz. i need to find a afm that i know is good. do you know of anyone that has one for a 91 turbo? only one junk yard here can get me one for $150 but i won't know for sure if it works until i put it on my car. thanks again for the help

 

[ccwade]

okay i know what tps is "throttle position center" how do you check that? does anyone have a ecu for a 91 turbo?

 

[grimreaper]

here is the tsrm (service manual) that will cover how to test just about anything on the car, http://www.cygnusx1.net/Supra/Library/TSRM/MK3/default.aspx

an yes it sounds like the afm is trash if your readings were all over the scale. post a wanted add in the for sale section. any afm from a turbo car will work regardless of year.