Assuming AFM is the culprit

[SPD TRP]

Running rich at idle, black smoke and such. Sometimes will stall on decel.

Check engine light on at idle.

Light goes off past 2,000 rpms and seems to run fine.

As soon as you decel to 2,000 rpms or lower, light back on.

Pulled codes---31---- AFM

Have any others experienced this with a bad AFM?

Is this how they go out?

I want to order the MAFT PRO, but don't want to buy another stock one in the interum, wondering will this get worse before the MAFT PRO arrives?

Any help will be appreciated.

Wayne

 

[T34418L3ONE]

i had the same problem with the afm, but then it mysteriously went away. Things i tried:
Ground afm to body via wire from one of the mounting screws
Check all engine grounds
check coilpack ground
check afm with ohm meter via the spec in the tsrm

 

[boost fiend]

as far as tthe coilpack ground, ive had mine off and had no issues. so have others.

 

[shaeff]

as far as tthe coilpack ground, ive had mine off and had no issues. so have others.

it's a not a BAD thing to have it, though. some experience a miss at idle when it's not there...

that all being said, i made my own. it took 5 minutes, including finding the wire... besides, would you rather the coilpacks short out to your fingers if you touch them/the bracket, or to the motor?

-shaeff

 

[SPD TRP]

Wondering if the AFM is that delicate?

 

[shaeff]

the AFM is delicate.

-shaeff

 

[SPD TRP]

Well, been searching like a madman and found out something interesting,
there have been quite a few people having problems with the AFM after cleaning and re-oiling their K&N filters, something about the mirror in the AFM.

I just happened to do this before mine took a crap on me and threw the code 31.

Just a little more information for ya'all.

Wayne

 

[NDBoost]

damn, AFM's and their pickyness. I need to clean mine because its covered in oil from my fucked over turbo. Im just hesitating because i know ill probably end up getting a new one..

 

[Red Dragon]

I've had almost teh exact same problems, and it happened right after reoiling the FIPK as well. hmmmm... sometimes it does it, sometimes it doesn't. and its just like you say, sometimes comes on at idle after a decel, but once back on the gas it goes away? And this is with a lexus AFM.

 

[jetjock]

You can check the AFM either by ringing it out as per the manual or measuring the signal using the frequency measuring function any decent DMM has after checking to see if the AFM has a good supply voltage and ground. Of course, a scope would be better but a DMM will do. As I recall it's around 20 at idle and 50 at 2000 rpm but don't hold me to that (I'll look them up if need be in the TCCS manual). Also check the AFM's air temp signal as it's separate.

Fwiw, running a FIPK isn't the best idea from a filtering standpoint.They flow well but filter very poorly. If you insist on using one you shouldn't clean it often and when you do keep the oil to a minimum. That said, I know guys who've run them for years and never had AFM problems. Now hot wire sensors, that's a different story.

Coil pack ground: Measure the voltage drop across it when it's disconnectd and you'll see why it's there.

 

[boost fiend]

i notice a slight miss at idle. i have a apexi intake system though. also no coil pack ground. so maybe ill rig one up and see if it goes away. let ya guys know tomorrow. too damn cold out to dork with it:evil2: