How to properly clean the early VAF sensor (1 Viewer)

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Dec 29, 2016
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Lawrence KS
I know the 94-94 VAF is something you don't want to go screwing around with. i have read the horror stories of people taking it apart and breaking the internal connections. I know with more modern MAF sensors you need to clean the little element every once in awhile. My question is does this need to be done with a VAF? if so how the heck do ya clean it properly? I did a search and did not come up with much.. Just stories of how not to do it lol.. Thanks!
 
The VAF is a Vane Air Flow sensor. It has a vane that moves with the air being sucked through. The controls are more like a TPS (Throttle Position Sensor) than the newer versions.

The MAF is a Mass Air Flow sensor and operates on thermal transfer calculated loss across a wire across the air stream. This is the one that must be cleaned because if it gets stuff caked on it, the thermal transfer is affected.

The AFM Air Flow Meter is also a vane style.

I'm sure others are much more knowledgeable than I and have touched more than one version.

Perhaps @jonheld ?
 
Honestly, I've never really cleaned any AFM/MAF other than an inspection of the flap movement and a wipe down with a rag.
Absolutely no need to clean this unit. It is not serviceable and Toyota does not make them anymore. Rockauto lists CARDONE 7420105 as a remanufacture replacement for mine ('91 with a 3FE) and to nobody's surprise it is unavailable. The vane door/hinge is very delicately balanced to accurately relate to the volume of air flow. Do yourself a big favour and leave it alone UNLESS at trouble code is pointing to it directly. I will scan the pages from the FSM and post tem when I get home later today. Tinker with it at your peril or go for it and afterwards you can park it on your front lawn and plant some flowers in the headlight pods :)

For the MAF sensor, typically a hot wire circuit is integrated into the MAF so that contaminants are literally burned of the sense wire by increasing the current to a point which will turn the wire red hot for less than a second.

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For over the past year I have been trying to figure out why my fuel mileage is so terrible.. I understand that these vehicles were never meant to be fuel-efficient, but last time I filled up I got a whopping 8.5 MPG mostly city driving. I mean come on that is awful even for a LC. I have checked\replced\fixed a laundry list of things over the last year with no help and this was kinda my last resort of things to check. Being that it is an OBD 1 vehicle and they no longer sell the Toyocom scanner I can't really get any real-time data that might help troubleshoot what is going on. I love everything about my LC for the most part, but every time I hit the gas pump it makes me want to sell it.. At this point, I would be fine with a vehicle that gets 12-13 mpg in the city.. That would be an upgrade for me lol.. So I guess I'll leave the ol VAF alone for now.. Thanks!
 
For over the past year I have been trying to figure out why my fuel mileage is so terrible.. I understand that these vehicles were never meant to be fuel-efficient, but last time I filled up I got a whopping 8.5 MPG mostly city driving. I mean come on that is awful even for a LC. I have checked\replced\fixed a laundry list of things over the last year with no help and this was kinda my last resort of things to check. Being that it is an OBD 1 vehicle and they no longer sell the Toyocom scanner I can't really get any real-time data that might help troubleshoot what is going on. I love everything about my LC for the most part, but every time I hit the gas pump it makes me want to sell it.. At this point, I would be fine with a vehicle that gets 12-13 mpg in the city.. That would be an upgrade for me lol.. So I guess I'll leave the ol VAF alone for now.. Thanks!
I have some info about the 3fe engine only
 
ariff before you try to clean your AFM, I think it would be best if you familiarize yourself with some words of wisdom, if it ain't BROKE, don't try to fix it!!!!
 
ariff before you try to clean your AFM, I think it would be best if you familiarize yourself with some words of wisdom, if it ain't BROKE, don't try to fix it!!!!
I am not planning on doing anything with it.. just wanted to check here first to see if there was anything I could do for it.. thanks
 
Hey guys, so I am planning on cleaning my whole intake (from filter to header) soon and installing a new filter at the same time. I get that the VAF doesn't have to be serviced, but will it be harmed by CRC intake cleaner? Should I remove it from the system before cleaning? I've never dealt with a system like this so I'm really not sure how to handle it.
 
Hey guys, so I am planning on cleaning my whole intake (from filter to header) soon and installing a new filter at the same time. I get that the VAF doesn't have to be serviced, but will it be harmed by CRC intake cleaner? Should I remove it from the system before cleaning? I've never dealt with a system like this so I'm really not sure how to handle it.
Remove it and put in a zip lock bag and put somewhere where it wont be knocked about.. Don't try to clean it or blow air through it or play with the flappy door or...
 
Remove it and put in a zip lock bag and put somewhere where it wont be knocked about.. Don't try to clean it or blow air through it or play with the flappy door or...
So don’t try to clean off the door or anything? My whole intake is pretty damn dirty, so I was going to just try to get the layer or dirt and crap off with a wipe-down or something
 
Absolutely no need to clean this unit. It is not serviceable and Toyota does not make them anymore. Rockauto lists CARDONE 7420105 as a remanufacture replacement for mine ('91 with a 3FE) and to nobody's surprise it is unavailable. The vane door/hinge is very delicately balanced to accurately relate to the volume of air flow. Do yourself a big favour and leave it alone UNLESS at trouble code is pointing to it directly. I will scan the pages from the FSM and post tem when I get home later today. Tinker with it at your peril or go for it and afterwards you can park it on your front lawn and plant some flowers in the headlight pods :)

For the MAF sensor, typically a hot wire circuit is integrated into the MAF so that contaminants are literally burned of the sense wire by increasing the current to a point which will turn the wire red hot for less than a second.

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Thank you for this post. You saved me fom tinkering with something I don't need to mess with - Noob.
 

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