causelexes

Hello,

Was wondering if anyone could tell me if the 1993 ES 300's MAF is a Karman-Vortex? Was trying to give it a clean with some CRC cleaner but wanted to make sure I wasn't damaging it like a doofus I don't think it is but better safe than sorry.

donbryce

Read up on here first. Lots of posts with folks regretting cleaning the MAF sensor. Consensus seems to be 'cleaning' will not make a noticeable difference, and causes more problems than it solves. This article discusses these devices, and includes a picture of the Karman-vortex design, so a visual check should tell you. http://www.autoshop101.com/forms/h34.pdf I'll check mine later today and post back...meantime, the part listing for a '93 es300 from web sources describes it as a vane type sensor...

causelexes

Did some reading...seems like most people with issues didn't let it dry after the cleaning, Others seem to be pretty satisfied, so I still figure it'd be worth it. Any word on if it's a Karman-Vortex? PS Thanks for the reply

SC400slide

iTrader: (11)

Any Lexus made before 1995 will have a Karmen vortex air meter type MAF, or in this case, AFM. (Air flow meter). If you were to clean the Karmen vortex AFM with CRC MAF cleaner, you will most definitely toast your AFM. The only way you can clean it is...well, you cannot really clean, the best you can do is use compressed air on it.

causelexes

Ok thanks for the info. Any advice on how to get to it to shoot some air on it?

causelexes

You can see a pic of it here http://www.carpartsshed.com/Catalog/...0Flow%20Sensor

There is only one part that seems removable on the top held in by two small black screws. Is this what I should remove to shoot with air?

donbryce

I lost it, but I just recently read a thread from a guy who removed the 2 screws holding the connector on and totally fubared his air flow sensor.

SC400slide

iTrader: (11)

The actual AFM is the black part that is held by the two small black screws. The large body around it is the AFM housing. The best you can provide for the AFM is to shoot some compressed air everywhere on it, and hope that cuts the mustard.
@ Donbryce, he just pulled the AFM/MAF out and it "busted"? He probably sprayed MAF cleaner on the thing and that toasted it. The CRC MAF cleaner has a warning on back of the can saying not to use it on pre 1995 models because of the Karmen vortex air meter type AFM's. Puredrifter is the expert on this stuff. He will know most likely

causelexes

Yeah I removed the two screws & started to slowly remove it, but felt a small resistance, so I figured to wait on some more info & just put it back. But now my car won't stay running
It just starts & dies. Any suggestions? I feel like completely removing it at this point...

causelexes

OK found this in another forum :

"How to clean the MAF meter in 1993 es300? I sometimes had hessitation during from stop acceleration. I tried searching the forum to no avail.

Search only resulted in MAF sensors for 94 and later models. After the fact, for 92-93 models, I found out they are aluminum meter boxes and not the typical black plastic sensor you can pull out and clean the filaments. I tried to clean my MAF meter using the MAF sensor cleaning guides on this board and elsewhere. Just a warning to those with the same model years. You can unhook the harness but do not unscrew the sensor and pull it out. You will tear out the contacts on the circuit board and lose your electrical conections if you do. No wonder Lexus no longer used the MAF meters and went to sensors after 1993.

I found out the hard way and forcefully pulled out the connector part (after I removed the screws) which I thought was slightly stuck in the aluminum housing. Turns out it was held in by the soldered connections to the circuit board. What a crappy design. I had to open the silicone sealed black plastic on top of the sensor to try to reconnect the wires and solder the contacts that tore off the circuit board. There isn't anything to clean in there. I thought I did it and resealed everything and installed. Start the car and the CEL came on and the car dies while idling after warming up."

SOOOOOOO...I probably screwed myself on this one

Hopefully anyone with a similar model can read this and avoid making the same mistake.

Just bought a used one online for $45 so I'll be waiting on it. Replacing should be no problem.

Power6

"MAF sensor cleaning" has to be the biggest car guy feel good placebo. If you have a problem with the car try diagnosing properly, usually that leads to best results.

causelexes

I was having a problem with a rough idle at stoplights/when stopped that started out of nowhere. I had a major tune-up done that was supposed to resolve it, but it didn't. Still has a rough idle at stops...lighting flickering as well on my a/c. Time for a new thread? lol

donbryce

You can now move on to IACV cleaning...another snake pit on the '93. Lots and lots of info on this. I spent hours on mine, finally bought a 'tested passed' replacement off EBay, works great now.

LeX2K

The airflow meter on a '93 ES is not designed to be cleaned, and it doesn't need to be either. It is a fancy variable resistor nothing more, if it shows issues you replace it, although they rarely go bad.

causelexes

Lexus 2000 said ,
"The airflow meter on a '93 ES is not designed to be cleaned, and it doesn't need to be either. It is a fancy variable resistor nothing more, if it shows issues you replace it, although they rarely go bad."

And as you can see here, that's absolutely correct. The circuit board was first installed & electrical connection second, then soldered together on very thin, aluminum foil-esque strips from the board.
After the connection was secured, they sealed it up with some silicone around/over the plastic housing top. Even barely moving it after removing the screws can break the connection, killing the sensor.

So remember, LEAVE IT ALONE! Unless you want to be posting one of these icons ->