Possible AFM problems?

[MK3Brent]

There is one small difference between the 89 afm and 87 sensor.

If you look under the "pillar" that the sensor stands in, you'll see a small hole at the bottom of the 87 sensor.

No clue what it's for though.

 

[gixxer750]

it's quite possible it's not your AFM. If you free rev the car a little, your readings shouldn't go over about 200hz. So if it is in that area, the AFM doesn't seem to be a problem. Is it still throwing a code?

Maybe your fuel filter is stopped up

 

[MK3Brent]

I don't think they went over 200hz, maybe 100 when I rev.

 

[MK3Brent]

PROGRESS


Both sensors have to be trashed.

Continuity on all afm wires tested just fine from the ECU to the harness at the AFM.
I reset the ECU, and I reset the S-AFC.

Started the car with NO AFM, and idle is perfectly sitting on 14.7 no bumps, misses, or sputters.

Narrowing it down straight to the sensors.
I'll be getting a confirmed good sensor soon, and I'll report those findings as well.

 

[hottscennessey]

I was going to say, try re-setting the ECU. I've had numerous problems with my AFR going lean or sporatic under boost, re-setting the ecu cleared them right up. I see you've already tried that, but just thought i'd post my experience. Good luck!

 

[MK3Brent]

Wasn't the resetting of the ECU so much... it was just trying to try every combination of things.

Idling w/o the AFM at all really proved it tonight.

 

[hottscennessey]

yup, something really funky must be going on with that AFM if it can hold a steady 14.7 from the O2 sensor alone.

 

[MK3Brent]

I knew it was the AFM when I noticed both sensors made the car run differently.

I can't wait to boost again.

 

[MK3Brent]

Just tried another sensor that had worked in October, but I'm still having the same issues.

I'm just going to pressure test the IC pipe system for any kind of bizarre leaks, then try again.
This is getting ridiculous.

 

[Nick M]

Toyota says to crimp the connection, then fill with solder. That doesn't mean a cheap butt connector obviously.

The best way to check the airflow meter is by looking at an 87 and an 89. Off the top of my head, I don't know if there are small differences or not. The plug could be slightly damaged from the light tug. I have seen it before also.

Im a retard sometimes. The 87 and 89 factory repair manual.:3d_frown:

 

[MK3Brent]

Your symptoms do point to an air flow problem of some kind. Maybe not the AFM but somewhere. It's a good technique to unplug a suspect sensor when the car is at hot idle because the ECU will revert to a default valve that's close to normal. If things improve you can go from there. I didn't see it but did you ever get a code 31? Or just the 24?

I did just that the other day, and it went straight to a 14.7 idle with no hick-ups.

When I was so quick to dismiss anything else as a problem and saying it was the sensor, I forgot to think about the possibility of my IC pipes not sealing 100%.

So I have the compressor now, I'll test it in the morning.

 

[MK3Brent]

I pressure tested the system.

One leak in a vacuum line, and one leak at the EGR on the upper plenum of the intake manifold.

Now I've had this area leak before, but never caused this problem before.
So I'll get a new gasket in there and see what happens.

 

[MK3Brent]

Problem Solved

New sensor for the AFM, and a new EGR gasket.

No more issues... my Karmen Hz sit at 38 now at idle, and the car pulls harder than before.

Thanks for all the help guys!