Karman Vortex Air Flow Meter supra turbo/lexus (Compatibility, NOT upgrade)

[professorbob]

Installed a new dealer supplied 94.00 Throttle Positions Sensor and now the engine starts and idles very well. Have decided that the Air flow Meter electronics needs to be replaced to allow the engine to develop proper shifting in the transmission and full range RPM. Ohms values are out of range on both the original and a used replacement I purchased.
I am in desperate need of replacement electronic for the air flow meter on my 89 supra turbo. Want to know that the Lexus electronics are identical to those for the supra turbo. They carry very different parts numbers. And, how far forward Lexus used the compatible electronics extend.
I see '92 forward Lexus mentions in ads, but know the Supra was changed in 1993.
Also does anyone know of an inexpensive replacement unit. Just not in a position to pay 350.00 for a rebuild unit and cannot trust the used parts.
Thanks
Prof.

[cre]

I'd rather keep the thread on the Lexus AFM that in the FAQ restricted to the commonly performed housing and injector upgrade. I'm going to move this to its own thread in the general MKIII section.

While the complete AFM assemblies (housing and sensor module) have different part numbers, the actual sensor module (just the electronics) have the same part number. There are a few different part numbers which may be present on the MKIII and Lex AFM electronics. These are found in the '90-'95 LS-300 and SC-400. You cannot buy the sensor assembly separately from the dealer though... Used is your only option. A complete, re-manufactured unit for one of those other vehicles may cost less though. In which case you would just swap the sensor assemblies and still save a little money, but I doubt you would save much.

Another option is a converter to convert to a different metering system. The MAF-T is a $200 magic box which allows you to move to a less restrictive, more common, cheaper GM MAF sensor. I've bought these sensors new for as little as $75 and used for as little as $5 (They're VERY common). There are much more advanced systems which offer this translation function along with many more bells and whistles, but this it the only one which would keep your bill below $300 (aside from buying and testing who knows how many used KVAFMs).

BTW, the resistance testing of the KVAFM is not a reliable testing methodology. It really needs to be test on the bench with the proper equipment and an oscilloscope.

[professorbob]

Purchased a used AFM but still have same problem with RPM drop at 2500 and Automatic Transmission A/T not shifting into 3rd.
The seller says he will swap another for the one I have. It does not spec out with the Data page on checking KVAFM with an Ohm meter.
He says that if his units do not throw a code on a downer vehicle they are goo. "Is this Correct?" I will be paying freight for the return and replacement. Trying to save on all this swapping..

[CanadianBak'inSupra]

have you checked trans. fluid and adjusted the auto trans kick down cable?