rangerruck

I've done a search, and cannot find any pics or vids on youtube, or here.
I have an 88 4rnr, and wanted to clean the maf just for craps and giggles. allready cleaned the throttle body. I found the maf sensor cable, and unhooked that, it plugs into a little box looking thingy , that is about 2 inches square, and solid metal. it has 4 screws, one in each corner. I undid all those, and tried to pull that little plate off, thinking the maf wires or resistor/diode setup was inside there, but it has some serious rubbery silicone type stuff sealing it all the way around, that would need to be razor bladed through. Is there a way to push back on the airvane, through the front where the air is forced, and spray some electronic cleaner up in there, and hit the components that need cleaning? thanks in advance.

scuba

Ummm, Just so you know, Its called an AFM...
Thats maybe why your search didnt net any results...
I know there was a thread on this aboot a week or two ago.
As for the "rubber silicone type stuff" That would be silicone gasket maker, Specifically to keep water out of that box...

I know you said you want to clean it for S&G's, But there has to be some underlying reason..?

rangerruck

a few reasons; to know how to do it, because prev owner proly never did it, 1 owner/wife car. because it has 240k miles on it, and the components/ temp wires are proly filthy/crusty. because I did change out the air filter, clean throttle body, and thought I should not overlook this.

rangerruck

...good to know, called an afm...

scuba

haha...Well...
Just so you dont end up spending major $$$

https://www.yotatech.com/forums/f116...-sound-123167/
Theres a couple good threads in post 3 of that thread...
Good luck

abecedarian

In general, it's not a part that requires cleaning and like the throttle position sensor can be easily damaged. All you really need to do is clean the bore with a MAF or similar cleaner.
If you're insistant on popping the top and cleaning the circuit board, use a high quality electrical contact cleaner and allow it to dry upside down so that lint/dust does not collect on it. Also, use a non-acetic-cure sealant to re-seal the lid: it shouldn't smell like vinegar- the fumes could be corrosive to the unit.

scuba

AAAHHH THANK YAA

rangerruck

Abe, I get it; just found this thread, and you are right, should really be sealed components, with no typical crap being able to get to it. I may look inside though, since I work on tiny electronic crap like this all day anyway...
http://www.4x4wire.com/toyota/minutemods/afm/

Georgiadave

It reads like you disconnected the receptacle side of the plug on the AFM, rather than the harness. The little blade connectors are just soldered to the circuit board and it is easy to pull then off the board.

The AFM is just a rheostat connected to a vane in the air passage. There is a good section in the FSM on testing the AFM.

Unless the AFM tests bad, and you have nothing to lose, I would not take it apart. They are pricey.

mt_goat

Do NOT take out those 2 screws that look like they hold the AFM plug in place.

iamsuperbleeder

lol, why does everyone ALWAYS go to those screws the first time around...

I know I didn't, I saw that little metal spring-clip and was like "ok, I see what's going on here"...

yeah, don't pull those screws out and yank on that plug...

if you do, you either better be good with a soldering gun, or you'r gunna pay some $$$ fer a new AFM...

There's nothing really on these AFM's to clean accept for maybe the little intake temp probe (the little white plastic doomahicky that protrudes down inside the AFM). It's a machanical based sencor; air moves the door inside, and sealed electronics under the black cover that's siliconed up reads how much the door's moving.

They can get "sticky" if you maybe suck up some muddy water, often causing them to stick either closed, wide open, or just stop them from fulling opening. The best way to try to un-stick them I've found is just to dry them out very thoroughly (if you DID suck up water to cause it), then hit it with compressed air from every angle you can. Then mabe put a straw on the end of a WD40 can and try to hit the two little bearings that door pivots on, then wipe off as much excess as you can.

On another note, unless you've done some major upgrades to the intake or exhause system (such as header and full open exhaust, or big-bore throttle body and a ported intake), there's really no need to muck with the AFM. Trust me, I tried and screw up my original; that's what brought me to yotatech 1600 some odd posts ago


Trav

mlrtime99

Be gentle in them there areas. The most I would do is blow some pressurized (low pressure) air from the reverse side. There's lots of wizardry at work in there.

iamsuperbleeder

well yes, there is, up under that little black plastic cover that siliconed on there. but in the AFM itself where the air passes through, it's rather robust considering it's all metal and there's no exposed electronics

now that doesn't mean you can freek'n soak it in a cleaner... you do that, and I garantee you that some will seep into where the eletronics are and ruin them...

but mine's been submerged under water more than once, and has had a good amount of water pass through it as well, and it still functions perfectly fine after a little R&R, according to my multimeter

rangerruck

Wow!!! it is sage advice when peeps tell you...mmeh... no need to do it.

rangerruck

lemme ask one more question about this then; has anyone around sealevel or less than 2000 ft above/driving, ever move the gear one tooth over, to make it run a bit leaner? I know at higher levels, dudes move this two teeth, especially if they are in Colorado or such, but what about in Houston? would moving the gear one tooth over, be dangerous or is it acceptable? Thanks.

abecedarian

the only problem you'll get is from the O2 which says "rich" or "lean". It doesn't say how much.
The ECU ends up bouncing around the O2 sensor's reading.
It's often referred to as "fuel trim".
Nutshell- O2 says lean, ECU goes rich. O2 says rich, ECU goes lean....
In a perfect world, your trim reflects 50% rich, 50% lean.