Can you tune up the AFM?

[TRDcelica90]

hey guys my adjustment screw on the AFM was messed with before i bought it.. it was running dangerously lean and would buck during cold start really bad.. i turned the screw a turn or two and made a big difference to the bucking so i tried to find a place where it felt right.

Can you check to see if the AFM screw if in the right position with say a multimeter or something??

im worried its still running lean or rich through diff RPMs and wont it all sorted.. any ideas??

do toyota have a special device to check/adjust so they can charge me an arm and a leg to use??

thanks guys

[JustCallMeOrlando]

The screw on the AFM is mainly used for idle fuelling. It should've been calibrated from the factory and it usually has the measurement stamped on the body near the screw. To meaningfully change the AFR's using the AFM you have to adjust its spring tension and that requires opening it up.

[TRDcelica90]

i know it makes a diff during normal driving though. because adjusting it will adjust how the car responds in all circumstances. including bucking through boost.. and when its adjusted it will change..

[HAVABEER]

i also thought that screw was just an idle adjustment and that the timing fueling etc was ECU controlled?

[litldv8]

what you need is a co meter put up the tailpipe and readjusted.
any competent mechanic should have one (or access the one).

[Z2TT]

Yeah you can adjust the mixtures with the spring tension, I did it on my 1g-gte and it feels a little more responsive, would be good to play on the dyno with it.

[Admiral coFF33]

Backyard spec is playing with AFM cog...

go get a SAFC2 , they are around $200 now and you can tune your fuel to your hearts content.

[andrew_mx83]

flap style AFM?

yes the screw is only for idle, it is an air bypass. so screw it out (counterclockwise) to let more unmetered air in and run leaner, or screw it down (clockwise) to let less unmetered air in and run richer. yes it will make a difference across the whole engine range but is mainly for idle as the effects would be bugger all once there is decent airflow.


to change running mixture take the plastic cap off and screw around with the spring tension

[amichie]

There is a marking on most AFMs showing the original setting. I will try and find the very old thread that shows you how to restore it to factory setting.

[amichie]

Found it.

There is a number stamped next to the plugged adjuster hole on the AFM.

the info stated that the number stamped was the depth setting from the top of the relief to the top of the screw head under the plug.

per the Toyota TCCS book

casting number/ distance from top of casting to top of screw
30 / 13.0mm
26 / 12.6mm
24 / 12.4mm

[TRDcelica90]

WOW.. fantastic mate.. also.. ive got a Emanage blue to install for fuel and ignition

[andrew_mx83]

then why fuck with the AFM?????