Relocated MAF, now problem

Grimsta

Supramania Contributor
May 30, 2007
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Santa Rosa, Ca.
Hey whats up. I built a custom CAI that goes down behind the headlight and i was using the MAF in its Lexus housing but that caused the air filter to sit way to low to the ground. So i removed the MAF itself out of the housing and installed it in one of the pipes closer to the turbo and now it doesn't accel. I have it facing the right direction but i have a couple questions.

1.These intake pipes are plastic, could the MAF possibly ground itself on its housing and is that my problem?
2. Where i put the MAF is on a 60 degree bend pipe, its right in the middle, but could it being on a bend be my problem?
3.Since these are Karman vortex would i have to install that mesh infront of it to generate the same kind of reading?
4. Does the shorter peg in the back of the sensor actually do anything? Is it a ground/temp sensor/something else, because i made a hole for that but maybe it isn't sticking down far enough. And in the Toyota/Lexus housings, the bottom of the MAF would set in a little round groove inside the housing, is that essential?

Go figure i try to improve something and F%*^ it up instead. Thanks for any help
 

starscream5000

Senior VIP Member
Aug 23, 2006
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Hot and Humid, KY
The AFM is most like running shitty as there isn't the correct amount of air traveling across it without the honeycomb in front of it and from the general shape of the AFM housing. In other words, you need to keep it in the housing.
 

hottscennessey

DONT BE A BITCH!
Jun 3, 2005
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Richmond, VA
Do you have anyway to tune? I hope so.. the only way to run an AFM in a custom housing is tuning for the new ammount of air entering the engine.. otherwise it's back to the old housing for you..
 

Grimsta

Supramania Contributor
May 30, 2007
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Santa Rosa, Ca.
Damn that sucks, thats what i thought. No way to tune but i have a stubby air filter i just picked up that may make it less close to the ground. But would it make that much of a difference because if what you say is true about tuning for a custom housing, wouldn't switching from the small supra afm to the larger Lexus afm cause that problem too? And if so would it cause it to completely take a dump when i open the throttle? WOuldn't it just lag or so.

Yes, i was trying to be a Pep Boyz Baller you! LOL
 

Grimsta

Supramania Contributor
May 30, 2007
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Santa Rosa, Ca.
Actually like the other guy in that thread i am running stock injectors and its rich.
Can anyone offer any other tricks i could do to possible get this running without having to put the lexus afm back in?

BTW i actually think the point where its at now would be smaller than the lexus. Its probably the same size as the Supras. Maybe i should try putting the honey comb infront of it and seeing how it fares?
 

Grimsta

Supramania Contributor
May 30, 2007
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Santa Rosa, Ca.
Yeah, i had to get a MAF adapter and drill some holes but i put back in sucessfully. I should start a build thread and show how to build the CAI on the 7m-GTE. ALex has a youtube on his NA
 

Doward

Banned
Jan 11, 2006
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Alachua, FL
Jesus, the AFM sensor will read differently if you change the cross section of air flowing across the sensor - increasing the cross section (aka putting it into a bigger pipe) will read as a lower velocity, and putting it into a pipe with a cross sectional area smaller than the stock housing will cause the afm to read higher than it should.

The Lex AFM works, because the housing is ~25% bigger - 25% injectors evens things out, but you're throwing off your timing map with this modification.
 

MassSupra89

Almost done.
Nov 3, 2005
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MA
Grimsta said:
3.Since these are Karman vortex would i have to install that mesh infront of it to generate the same kind of reading?

That's what makes the "Vortex" in "Karman Vortex"

Air passes through that mesh(honeycomb) and is spun past the sensor, the sensor then reads the vortices, and that is how air is metered on our AFM's
Any disruption with that honeycomb will ruin the AFM's readings. I can't even imagine what would happen taking it completely out.
 

Grimsta

Supramania Contributor
May 30, 2007
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Santa Rosa, Ca.
It sure is a poopra, i put everything back together and it works smoothly now. Well, not so much, as i was reinstalling the MAF in the Lexus housing I F$#&^ing dropped it and now it hiccups intermittently!! Throws me the codes 24 and 31. I'll check the wiring before i go drop a load on a used MAF cuz i had to extend the wires to reach where the MAF was previously (2" off the ground) so hopefully some connection just got loose with all the plugging and unplugging i was doing, but i kinda doubt it. F%^(*ing old cars! lol