possible mass airflow sensor problem!!!!! please check out my dilemma!!!

[the t3d]

alright i gotta problem.
i was making a custom intake tube for 87 supra and when i finally got everything to fit right, the fuckin car would start right. i was like WHAT THE FUCK! but i looked at the connection and i noticed that one of the prongs were missing, so maybe the sensor is having a "miss". and one of the clips to secure it down is broken off. i just unplugged it and tried to start it up to see if i got the same start-up issue, but it was like TOO much airflow and with it in, it was like NOT ENOUGH airflow....
i'm think it's that missing prong...

I thought i'd help my description with some pictures of what i'm talkin about......
PLEASE HELP ME!!!!!!!!

 

[supraman7mgte]

check the terminal vs the plug in,see if the same number of pins matches

 

[the t3d]

well, i did, and all of them are there where you are supposed to plug it in, so i'm thinkin it might of broke up when i took it off. i'm thinkin of just goin to a junk yard and cutting the "plugin" off another supra and connecting the wires and hopefully that might work, but i'm not exactly sure if that's the problem

 

[Figit090]

that custom intake PVC-looking thing.....does it have a vacc. line feed? i believe your vacuum system should have a line running to it....the stock setup does and if you forgot that, i'd wait for more confirmation to see if you NEED it. b/c it might be your problem. good luck.

 

[the t3d]

that custom intake PVC-looking thing.....does it have a vacc. line feed? i believe your vacuum system should have a line running to it....the stock setup does and if you forgot that, i'd wait for more confirmation to see if you NEED it. b/c it might be your problem. good luck.

i think you might be right, i'm goin to drill a hole and make alittle vacuum nipple and attatch that hose...we'll see if that works

i hope that works...'cause if it doesn't, i'll be pissed...at myself!

 

[Figit090]

umm....i could just go out tomorrow and pinch mine off....

then i could tell you and save you the trouble of potentially mucking up your intake. but whatever....

lol.

let me know and i'll squeeze it...if i can reach it with the motor running. if it runs like shat then we have an answer.

but somebody's gotta know what that line does..... anybody?

BTW i have no idea what the vaccuum system does or why its needed but i know its very important, and that your engine will not run without it. that being said...having the line attached to your intake removed is probably not a good thing....but i dunno. PM somebody that would know.

 

[johnathan1]

That vacuum hose is for the PS system (Idle-up Valve), IIRC. And you would have to let it just suck in unmetered air, Figit, not pinch it.

 

[Facime]

John is correct, its only for the idle up. I used my stock accordian hose when I made my NA intake, and just cut it down to coupler sized, leaving the vac port on it and usable. Its is very unlikely that is causing your problem. If you havent figured this out by tomorrow I will go take a look at my NA wiring and try to see what wire you are missing.​

 

[the t3d]

it's driving me nuts!
i looked at my friends 1990 supra na, and he has that prong thing missing, so i don't think that's it, and the other thing that through me off was he had his vacuum line closed off. i don't know if it's because i went to 2inch piping or maybe there's a bad connection with the PVC pipe...if there was a leak would that be the cause? if i can't figure it out, i might have to replace the whole sensor...I DON'T WANT TO DO THAT!!

 

[miekedmr]

thats not a mass air flow sensor, BTW, its an Air Flow Meter.
My toyota pickup uses the same thing. So do ford probes (mazda 2.2l) and mazda 626's. (They're actually interchangable!)
I put an AFM from a ford probe in my 22RE pickup (higher compression, bigger cam, intake and exhaust) and after messing with the spring tension in the AFM to get it to scale the same, it has a very noticable improvement in top end. Its the same housing as the toyota pickup one, except about 30% taller and with a 30% bigger flap in it. I'd be curious to see how it compares to the NA supra one..

 

[the t3d]

thats not a mass air flow sensor, BTW, its an Air Flow Meter.
My toyota pickup uses the same thing. So do ford probes (mazda 2.2l) and mazda 626's. (They're actually interchangable!)
I put an AFM from a ford probe in my 22RE pickup (higher compression, bigger cam, intake and exhaust) and after messing with the spring tension in the AFM to get it to scale the same, it has a very noticable improvement in top end. Its the same housing as the toyota pickup one, except about 30% taller and with a 30% bigger flap in it. I'd be curious to see how it compares to the NA supra one..

that's what i meant


i'm gonna toy with it when i get back from physical therapy

 

[Figit090]

That vacuum hose is for the PS system (Idle-up Valve), IIRC. And you would have to let it just suck in unmetered air, Figit, not pinch it.

ok then. thanks for clarification..its just something that popped into mind when he said he made that specific intake mod and could have neglected the vac hose...

 

[Figit090]

t3d- did you touch ANYTHING else besides the intake pipes, AFM, or air filter?

just a weird check here but...you dont have anything obstructing the intake do you? i dont know how airfilters are packaged but i could imagine if they had some sort of guard against foreign objects during shipping...maybe something is still in the filter? thats only if you changed it though. it could be dirty but that wouldnt explain why it didnt keep you from startup before...

check fuses?

 

[the t3d]

haha well i got it working!!!!
i think it was just i had the piping alittle offset causing too much restriction, but i fixed everything. i'll take a picture and show you how it looks. i don't care if it's a PVC pipe, it's sure better than the stock tubing. =0)

the only bad thing...
the car idles at almost 1200rpms
so i gotta get that adjusted

 

[Figit090]

lol....uhh....even after warmed up? did it do that before??

is this because you releaved some restriction or what? thats kinda high....lol.

i think its fine...in fact i might do the same thing!

how much louder is it?

stock airbox?

 

[the t3d]

lol....uhh....even after warmed up? did it do that before??

is this because you releaved some restriction or what? thats kinda high....lol.

i think its fine...in fact i might do the same thing!

how much louder is it?

stock airbox?

well, at first after i first got it started, it was idling at like 2200rpms
i was like WHOA WAY TOO HIGH THERE
so, i gave it some gas, and then it went down to like 1200
i can feel alittle power difference when i give it some gas and its alittle louder as well...so, i'm happy with that.
sadly i was only able to do 2 inch PVC piping, 3 inches wouldn't fit, which is GAY!
it is the stock airbox...=0( but i'm just waiting for alittle money to roll around to get the KnN FIPK kit

doin all that shit... took alot of cutting and shit and finding the right fitment...it's still doesn't fit perfect, but it's good enough to get the job done.
it's all gonna perfected at a later time.

=0)

 

[Figit090]

cool. umm... so do you hear more engine noise or intake air rushing?

i'm thinking about eliminating my resonator...and my piping on the TB is on its way out anyway....

how large is the throttle body? 3 in? why couldnt you fit 3in?

 

[the t3d]

cool. umm... so do you hear more engine noise or intake air rushing?

i'm thinking about eliminating my resonator...and my piping on the TB is on its way out anyway....

how large is the throttle body? 3 in? why couldnt you fit 3in?

well, since it's idling alittle high, i hear more engine
yea i am so happy to get rid of that can we call a resinator...haha
the throttle body is surprisingly about 2.75 inches...that why i had to down grade to 2 inch piping

 

[johnathan1]

That's cool you got it fixed. did you re connect the p/s vac line? Or was it connected all along?

On a side note...I hacked up my stock airbox today, I cut out the front, so the filter is totally exposed (stock filter)...I just left enough of the front of the airbox to hold the filter and bolt to the car. And DAMN it is soo much louder now! I can hear the turbo sucking in air like crazy, and the sound the BOV makes is much clearer, and a bit louder...it made a BIG difference, I didn't realize how restrictive that thing is!! Now, if I could just get a K&N drop-in filter to replace the ancient, dirty-as-hell stock filter!

 

[the t3d]

yea i bet just wait til you get rid of the entire stock intake box
i'm waitin til i get the KnN FIPK filter and then i'm completely removeing the box all together...that'll be nice...=0)