Final question ... Does anyone know what went here (see pic). It was siliconed up by previous owner. The silicone was starting to crack, so I pulled it out took a pic then resealed it.
3-FE VAF Meter Woes: Lesson learned the hard way (1 Viewer)
- Thread starter spdwaver
- Start date
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Nice!! 
In your first pic in that post, there's supposed to be a plug there, but then an adjustable screw to allow air to bypass the AFM. Is that what you saw?
Curtis
Wow!!!! thanks for the great write up & pics, note to self dont f with this 
TrickyT
Hate that mud...
You are to be congratulated on your perseverance. Nice job and good pictures. You can see in the 2nd and 3rd pics of post #34 and 1st pics of posts #35 and #37 that there were small metal tabs that used to be fastened to the PC board and that these were then soldered to the connector terminals during the OEM assembly process. You did great to get them re-attached to the PC board because there wasn't all that much metal left on the board. You definitely owe yourself a beer or two.
Very nice pics. Do yourself a favor and pick up a Weller iron and 2 or 3 different tips. Good tools are always worth the investment.
Good job. Glad you're back together.
Good job. Glad you're back together.
Thanks for the pat on the back! I was pretty happy with myself (after two near strokes and one temper tantrum). Good news is the plug works.
One thing I did not mention is the three prongs are not soldered to the board. They simply press against the solder, Once I was able to stick the solder to the board I did not want to mess with it.
Now the plug is removable without destroying the AFM, not that I will EVER remove those screws again!!!
Feels good to give back to Mud, I hope this helps save someone else some cash in the future. A must read for 91/92 FJ80 or others with same 3FE VAF/AFM
One thing I did not mention is the three prongs are not soldered to the board. They simply press against the solder, Once I was able to stick the solder to the board I did not want to mess with it.
Now the plug is removable without destroying the AFM, not that I will EVER remove those screws again!!!
Feels good to give back to Mud, I hope this helps save someone else some cash in the future. A must read for 91/92 FJ80 or others with same 3FE VAF/AFM
Sadly I have become the latest victim of removing the two screws and pulling the connector sort of out !!!!! Your write up is great I am going to have to do it myself in the next week ... Here is to hoping is all goes well!
I could really use that $700 for a new battery, O2 sensor among other bunches of things !
I could really use that $700 for a new battery, O2 sensor among other bunches of things !
also works on VAF Meter for 1990 Toyota 4WD Pickup 22RE
Thank you. After several days of diagnosis, that actually solved the problem. I think the original problem, that stopped my truck cold while accelerating from a stop into a right turn, was the main O2 sensor's plug and wires near it. EFI 15A fuse blew and would not quit blowing. No gas visually looking into the EFI chamber, so first thought must be fuel pump. Jumper in diagnostic plug trick and ignition to on would not trigger fuel pump either. Ordered $126 fuel pump. Last ditch effort, connected my fuel pump direct to battery with jumper cables and small wire jumpers and it ran great. Cancelled fuel pump order.
Proceeded with good advice to get a bunch of 15A fuses, install a good one in the EFI fuse slot, and remove each component of that circuit, one at a time, and try to start, and check for blown fuse. IF IT BLOWS, the unplugged component is NOT the problem area. Plug it back in, put another 15A fuse in, and unplug the next component in the circuit until you find the one that, WHEN IT'S UNPLUGGED, DOES NOT BLOW THE FUSE UPON STARTING. That is the problem component, if it is a component. (I had a tough time keeping that straight during this project, and because of that, I think that during diagnosis I compounded the trouble by overzealous but not entirely rigorous checking of the EFI fuse circuit's components.) Tried UNPLUGGING first one, then the other O2 sensor and each of them DID blow the fuse when unplugged, so WERE NOT THE PROBLEM. Cancel $80 sensor order. While I continued on, inspecting the VAF meter, which didn't seem to test out quite right, my buddy looked under at the O2 Sensors' wires. Main O2 Sensor Plug and nearby wires turned out to be melted, so rebuilt the connection, hardwired with crimp tubes. (Will go back and rebuild with spades when the sensor fails).
Back to me, under the hood, the Volume Air Flow meter, as so many here have learned, doesn't like fiddling. When unplugged, NO FUSEBLOW, so that's the problem, I thought. Tests were off a little plus that's where the fuse survived, at THAT unplugging. Ok, so sourced that...Ouch. $145 used or bugeyed $775 new. Was to c/b and order today, resolved to research further until end of day. Found this page. . Attempted my only 3rd ever soldering task, resin core for electronics solder and my cheapie Weller beginners model iron. Peeled out the sealant, popped the cap, it was exactly as described.
BEFORE SOLDERING!! Inspect the first 2 contact blades in there, the vertically inclined ones, (first one movable, second one solid, tiny set of points between them). These 2 have to be arranged just so, relative to the bent arm which moves in there when you manually open the air flap. There's a little wear spot on the moveable contact; that is a hint as to which side of that arm that contact should be placed on. When assembled properly, and held together carefully, manually opening the air flap allows the moveable contact blade's "point" to make contact with the fixed one's tiny point platter, for lack of a more proper term.
I then made the 3 solders, put it back together with tape over the cap, cuz I don't have that kind of sealer, but will get & seal. Reinstalled VAF meter, new fuse, deep breath, turn key...many tears of relief as she runs beautifully again. My friends are very proud of me and I am experiencing an unusual level of self -satisfaction. Thank you for this bunch of postings. You saved me way more than $. I cannot survive out here off grid in the boonies keeping farm animals, without my truck. Bravo.
Thank you. After several days of diagnosis, that actually solved the problem. I think the original problem, that stopped my truck cold while accelerating from a stop into a right turn, was the main O2 sensor's plug and wires near it. EFI 15A fuse blew and would not quit blowing. No gas visually looking into the EFI chamber, so first thought must be fuel pump. Jumper in diagnostic plug trick and ignition to on would not trigger fuel pump either. Ordered $126 fuel pump. Last ditch effort, connected my fuel pump direct to battery with jumper cables and small wire jumpers and it ran great. Cancelled fuel pump order.
Proceeded with good advice to get a bunch of 15A fuses, install a good one in the EFI fuse slot, and remove each component of that circuit, one at a time, and try to start, and check for blown fuse. IF IT BLOWS, the unplugged component is NOT the problem area. Plug it back in, put another 15A fuse in, and unplug the next component in the circuit until you find the one that, WHEN IT'S UNPLUGGED, DOES NOT BLOW THE FUSE UPON STARTING. That is the problem component, if it is a component. (I had a tough time keeping that straight during this project, and because of that, I think that during diagnosis I compounded the trouble by overzealous but not entirely rigorous checking of the EFI fuse circuit's components.) Tried UNPLUGGING first one, then the other O2 sensor and each of them DID blow the fuse when unplugged, so WERE NOT THE PROBLEM. Cancel $80 sensor order. While I continued on, inspecting the VAF meter, which didn't seem to test out quite right, my buddy looked under at the O2 Sensors' wires. Main O2 Sensor Plug and nearby wires turned out to be melted, so rebuilt the connection, hardwired with crimp tubes. (Will go back and rebuild with spades when the sensor fails).
Back to me, under the hood, the Volume Air Flow meter, as so many here have learned, doesn't like fiddling. When unplugged, NO FUSEBLOW, so that's the problem, I thought. Tests were off a little plus that's where the fuse survived, at THAT unplugging. Ok, so sourced that...Ouch. $145 used or bugeyed $775 new. Was to c/b and order today, resolved to research further until end of day. Found this page. . Attempted my only 3rd ever soldering task, resin core for electronics solder and my cheapie Weller beginners model iron. Peeled out the sealant, popped the cap, it was exactly as described.
BEFORE SOLDERING!! Inspect the first 2 contact blades in there, the vertically inclined ones, (first one movable, second one solid, tiny set of points between them). These 2 have to be arranged just so, relative to the bent arm which moves in there when you manually open the air flap. There's a little wear spot on the moveable contact; that is a hint as to which side of that arm that contact should be placed on. When assembled properly, and held together carefully, manually opening the air flap allows the moveable contact blade's "point" to make contact with the fixed one's tiny point platter, for lack of a more proper term.
I then made the 3 solders, put it back together with tape over the cap, cuz I don't have that kind of sealer, but will get & seal. Reinstalled VAF meter, new fuse, deep breath, turn key...many tears of relief as she runs beautifully again. My friends are very proud of me and I am experiencing an unusual level of self -satisfaction. Thank you for this bunch of postings. You saved me way more than $. I cannot survive out here off grid in the boonies keeping farm animals, without my truck. Bravo.
Lesson learned
Very good write-up, Secret Squirrel.... This really did a lot to help and guide me in fixing my problem...
Very good write-up, Secret Squirrel.... This really did a lot to help and guide me in fixing my problem...
You are welcome, glad it helped. I remember that day very well!!!!!
Update, I ended up trading my FJ to the original owners son for a 69 short bed C-10, which I have since restored.
Still hitting the forums from time to time though.
Best of luck!
Update, I ended up trading my FJ to the original owners son for a 69 short bed C-10, which I have since restored.
Still hitting the forums from time to time though.
Best of luck!
Thanks for the writeup! I will be undertaking this task very soon as I just loosened those damn screws, and pulled the plug...arghhh!!!!
Under that drilled out cap "should" be and idle air by-pass screw which is preset at the factory.I have drilled and tapped out the aluminium plug so that I can adjust it and re-plug it with a fine thread bolt and alloy washer - YES you can fiddle with it to get a better idle mixture (usually leaner), and it slightly affects the mixture throughout the range as well. Adjusting it in conjunction with a timing advance and the "magic screw" (idle screw) makes mine run a lot better and slightly better consumption, which works out to be equivalent to 12mpg (US gals that is) running 33's, winch, bar,drawers loaded with recovery gear etc. I am a mechanic by trade and have played with FI for a while, but I would NOT be playing around with the contacts under that cover (except fore just spraying some contact cleaner around in there) but you can search for how to adjust the tension of the spring for the flap which "may" yeild better economy, but you need to be uber careful fiddling around. BTW over here down under, a new AFM costs $1300, and second hand probably $250, so I don't fiddle too much with it.
Is there a step by step for how to remove the intake? I keep finding these cautionary tales (super helpful!), wanting to tackle cleaning the throttle body soon.
clarification - to remove the intake, you unbolt the sides and leave the harness plugged in?
clarification - to remove the intake, you unbolt the sides and leave the harness plugged in?
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