99 3.4 Supra MAF mod

Someone please help me with my Toyota Supra MAF thinking about going back stock because truck keeps stalling out on me. What wires do I i need to switch back.

 

OK - First of all Welcome. Second of all you gotta give us some context. Why do you have a Supra MAF in your truck?

 

I bought the truck with It believe people do it too gain a few h/p. It has a s/c on it. Also thank you for welcoming me. Keeps throwing a maf code and to replace the Supra MAF cost big money so am considering going back to stock. Then having it returned I suppose.

 

I would bring it back to stock. A MAF not made for the engine would throw everything off. Any HP gain from a Supra MAF is negligible (if any at all, does changing the MAF even do anything?)

 

I'm confused by this. Why would changing the MAF help with HP? All it does is read airflow and the engine ecu is what dictates what to do with that information correct?

 

Yep. @Toyota88. Derp.

 

If anything you should've switched to Supra injectors. Not MAF

 

if i remember right the supra maf was a popular upgrade for a while because the meter was less restrictive... I dont remember having to repin the connector though..

 

IIRC it makes the truck run lean enough to throw a code. If you recalibrate it, it'll work. But even at 10 psi (and whatever CFM) my stock MAF doesn't seem to be any sort of restriction. I would say go back to stock.

 

hope this helps

 

Let me start by saying I have been running the Supra MAF since 04

It's more than negligible. From mid to top you can really tell. It was very similar as going from stock manifolds to TRD headers. It pulls quicker.

Correct, it helps by removing the biggest restriction in the intake. Have you seen a stock bullet style MAF?

Derp

Exactly. I had to re-pin 2 positions when I did mine. In toyota88's pic he has two wires that need to be swapped and I have been helping him through PM's.

I bet you would be surprised if you did. I followed your build. I have a turbo setup waiting to go in myself but won't do it until spring so the truck isn't down while snowboarding season is still in play.

 

It would be interesting to see what the difference would be, and with the AEM making it work should be easy. The only thing is, is that on my 99 the internal diameter of the MAF (where the sensor sits) is 2.5" (the couplings for the IC pipe are 2.75" to 2.5" adapters from when it was cut from the airbox) and so is my IC piping, If anything is a restriction, it would be the IC pipes, and at that point Im making enough power for two 5VZ's lol. The best size IC pipe to run (so you don't have to do a bunch of adapters) would be 2.75" piping as that is what the throttle body is. If I don't find it myself tag me in your build when you get started!

 

Good points and I will keep your knowledge in mind! The '98's and down had that massive bullet in the MAF and you reminded me yours is a '99 which is when Toyota started to change to the new style. Much less restriction! I will probably convert to the new style at some point since I have everything.

 

That makes sense, it's more of a larger overall I.D. for more air flow than a sensor reading issue.

 

I switched back to stock airbox and repined the two brown wires. Truck started and died right away. I can unplug maf and it idles and runs in limp mode I’m assuming. But as soon as I plug in maf it dies. Tried to hook up this obd and could not get it to connect to my computer using obd doctor free version. @elnip has been very helpful and actually helped build the truck which is nuts small world. Just need to get this guy running and in the woods again. Thanks for all the help

 

Happens more than youd like to hear buuuttttt.....

is the MAF in/wired backwards?

 

As Brice said, going back to the stock MAF your will have to re pin and you may have a few in the wrong positions.
I'm not sure what year @Empty_Lord posted the schematic but it shows;
Pin 1 W-R
Pin 2 Br-W
Pin 3 G-R
Pin 4 Y-G
Pin 5 Br-B
The wire colors match so it may be spot on.

@Brice Can you verify that on a 99 schematic? '99 was a transition year for many things including MAF style so just want to be sure.

@Toyota88 They quit supporting the BR-3 a long time ago. You need the BR-3 S/W for it to work and I have no idea where you could get it.
Also snap a pic of how you wired up the stock MAF

 

I have no idea why it linked the whole post........

 

Lol

I can check and see if I have that schematic yes, it'll be later today though

 

Cool, no problem and thank you.