camry air flow meter?

[kelner]

I've been searching for a way to be rid of my airflow meter since my third one just threw in the towel on me. I've gotten two from the junkyard previously, but after visting several this weekend I was unable to turn up any cressidias or supras that had an AFM on them.

I was poking around the net looking for an alternative or different car to get one from and I stumbled across the aftermarket replacement by cardone ($250... sheesh) and they cross reference their item as being good to use in the following vehicles:

LEXUS
1990 - 1991 ES250
MAZDA
1986 - 1988 RX-7
TOYOTA
1988 - 1991 CAMRY
1986 - 1993 SUPRA

So this made me go out and search for a picture of the camry unit and I found this (engine bay might look funny to you guys, that's because it's in a mk1 mr2):

This is from a V6 (2VZ-FE) Camry. I was wondering if anyone knew about interchangibility between the two? This would give me a slightly larger pool to search from at the junkyard.

Then I looked up the Rx-7 flow meter to see what I could find. Looks similar on the outside and inside and looks to be 7 pin as well!

So my great big question is... does anybody know of alernatives to the AFM (other than maftpro and going with a aftermarket AFM unit)? Cheap and easy are key here

 

[Slow_Sc3]

cheap and easy wouldnt be maf pro, i guess try the camry and mr2 afm and let us know.

 

[kelner]

my friend has a rx7 afm left over after a na to turbo swap. I'll take a look at it and report back here.

 

[SupraMaster]

Hell, I have a friend with an '88 RX-7. I'll drive over and swap 'em out and get back to you on this.

 

[Nick M]

The electronic portion of the meter is the same in several models.

 

[kelner]

Hell, I have a friend with an '88 RX-7. I'll drive over and swap 'em out and get back to you on this.

I appreciate that! I'm going to try and look at his tonight and take readings on it, maybe we can come to a conclusion between the two of us.

The electronic portion of the meter is the same in several models.

What models are your referring to or know of? I can adapt an intake or filter if the dimensions or connections are different. It's the reading and electronics I need help with!

 

[Setheroo]

My buddy used an old AFM that I had lying around on his 4AGE swapped Celica.. it worked for him there.

I have also used one from an RX-7 for my car... they are all the same manufacturer and everything as far as I know.

 

[CRE]

They do not all use the same scale for the signal, nor are they all the same size. If the signal scaling matches (ie: 2.50v for a 50% open vane) but the opening and bypass are smaller the ECU will add too much fuel as the pvane moves and won't correct until it sees the mix is WAY off. So, yes, in such a case they will work (as long as the signal scaling is the same) but the car may not run efficiently or it may flat out run like crap.

BTW, a MKIII's VAF does NOT work in a '93 LandCruiser.

 

[kelner]

They do not all use the same scale for the signal, nor are they all the same size. If the signal scaling matches (ie: 2.50v for a 50% open vane) but the opening and bypass are smaller the ECU will add too much fuel as the pvane moves and won't correct until it sees the mix is WAY off. So, yes, in such a case they will work (as long as the signal scaling is the same) but the car may not run efficiently or it may flat out run like crap.

BTW, a MKIII's VAF does NOT work in a '93 LandCruiser.

Thanks for the info. I know the rotary is "rated" at 1.3L but effectively doubles it's displacement to 2.6L so it should be somewhat close? The 2VZFE is 2.5L as well so I'm not too sure how that will play out.

 

[Nick M]

What models are your referring to or know of? I can adapt an intake or filter if the dimensions or connections are different. It's the reading and electronics I need help with!

How did your old meter throw in the towel? Aside from drop kicking it, I don't see what could be wrong.

I think the MR2 turbo model works, but you still could have the problem pointed out by CRE.

 

[CRE]

The two things to consider if the electronics are compatible but it's of a different size are: Erratic tip-in and choking at higher RPM.

The VAF can go out fairly easily, it's an entirely mechanical contraption. It's not built much different than a TPS which most acknowledge to be a wear component (which should be replaced periodically). I have had one fail on me, not from wear but a fracture in the circuit.

 

[jetjock]

^ Exactly. Since it's a wear item and since he appears to be sourcing them from junkyards it's no wonder they keep failing...

 

[kelner]

How did your old meter throw in the towel? Aside from drop kicking it, I don't see what could be wrong.

The reading between the third (E2 I believe) and seventh (THA) pins is wrong. When I opened it up these two have wires leading to air temp sensor. I assume the connection inside of there is bork'd.

Erratic tip-in

I am not familar with that term, mind explaining?

The VAF can go out fairly easily, it's an entirely mechanical contraption. It's not built much different than a TPS which most acknowledge to be a wear component (which should be replaced periodically). I have had one fail on me, not from wear but a fracture in the circuit.

I'll assume VAF = Variable Air Flow? Are you referring to the AFM or some part of it? I haven't been introduced to this acronym either. Sorry :1zhelp:

Edit:

^ Exactly. Since it's a wear item and since he appears to be sourcing them from junkyards it's no wonder they keep failing...

My situation currently does not allow for me to make $200 purchases (this is for the cheap after market meters) on a whim and I don't expect them to last forever (since my original died I assume most AFMs I will be getting from the junkyard are on their last legs as well). I can pick them up for $15-$30 from a junkyard and that's a lot easier on my wallet but a much bigger head ache (I'd explain myself but this isn't a blog).

My main reason for this thread is to find alternative vehicles to get an AFM from or possibly a cheap alternative (not any that I've found so far).

 

[CRE]

The reading between the third (E2 I believe) and seventh (THA) pins is wrong. When I opened it up these two have wires leading to air temp sensor. I assume the connection inside of there is bork'd.

Hahaha, you said Bork'd... that rhymes with "PORKED"!!!! oon::yelrotflm

There's a thermistor between the two it's used to determine air temp. They can shift over time causing your mixture to change while the ECU's operating in "open loop".

I am not familar with that term, mind explaining?

Lets just say that when you start causing a big shift in air fuel the ECU has some preset expectations as far as how much air to expect from the change and when. If you gun it the ECU may go (again, here's that term) into open loop and stop adjusting the fuel levels, resorting to fueling per preset fuel maps and engine speed. Since less air is actually coming in the mixture goes rich... how bad it is will vary. On the road when the throttle is partially engaged it can simply cause sluggishness. From a stop at idle the car could stall, lurch or stumble a bit.

I'll assume VAF = Variable Air Flow? Are you referring to the AFM or some part of it? I haven't been introduced to this acronym either. Sorry :1zhelp:

VAF = Vane Air Flow (7M-GE has this)

MAF = Mass Air Flow (Another type of air flow meter, more common in domestics I think. VERY inexpensive and very common.)

KVAF = Karmen Vortex Air Flow (7M-GTE has this. VERY Delicate, quite precise, and you'll hate to have to pay to replace one.)

MAP = Mass Air Pressure (This is used in conjunction with an IAT sensor to determine air flow from manifold pressure and air temp. It's a VERY inexpensive sensor, quite accurate and imposes pretty much NO restriction on your airflow. And NO, you can't just throw the sensors under the hood, you'll need some hardware to translate.)


AFM = Toyota's generic term for an air metering device, regardless of type.

Edit:


My situation currently does not allow for me to make $200 purchases (this is for the cheap after market meters) on a whim and I don't expect them to last forever (since my original died I assume most AFMs I will be getting from the junkyard are on their last legs as well). I can pick them up for $15-$30 from a junkyard and that's a lot easier on my wallet but a much bigger head ache (I'd explain myself but this isn't a blog).

My main reason for this thread is to find alternative vehicles to get an AFM from or possibly a cheap alternative (not any that I've found so far).

Heh, yup, a lot of us have been there... well not quite but close enough. It took 2 AFMs for me to finally just dig in and figure out the MAFT Pro. I bought it quite some time before for down the road... good thing too, don't think I would have had the cash available anytime after that. NO, the MAFT Pro isn't a cheap setup... well, once it's in it is, but the initial cost is high for some.

 

[kelner]

There's a thermistor between the two it's used to determine air temp. They can shift over time causing your mixture to change while the ECU's operating in "open loop".

Is it possible to replace the thermistor? The more I think about it, the less sure I am of my memory. That is, I do not clearly recall which pins resistance were wrong from this weekend. I will have to check again when I go back to my mother's house where the car is.

Lets just say that when you start causing a big shift in air fuel the ECU has some preset expectations as far as how much air to expect from the change and when. If you gun it the ECU may go (again, here's that term) into open loop and stop adjusting the fuel levels, resorting to fueling per preset fuel maps and engine speed. Since less air is actually coming in the mixture goes rich... how bad it is will vary. On the road when the throttle is partially engaged it can simply cause sluggishness. From a stop at idle the car could stall, lurch or stumble a bit.

Makes sense. Another question for you: Earlier you had said "If the signal scaling matches (ie: 2.50v for a 50% open vane)" and that if the cfms that the unit can flow are different the ecu will not know to respond to less or more air because it doesn't know about it.

Is there any way to really check how many cfm (I am going to do some googling after this and see what I can turn up) and how to check the scaling on the unit?

MAF = Mass Air Flow
MAP = Mass Air Pressure

Quite familiar with both of those, my other project is a 3800 series II and it uses a 3 bar map.

Heh, yup, a lot of us have been there... well not quite but close enough. It took 2 AFMs for me to finally just dig in and figure out the MAFT Pro. I bought it quite some time before for down the road... good thing too, don't think I would have had the cash available anytime after that. NO, the MAFT Pro isn't a cheap setup... well, once it's in it is, but the initial cost is high for some.

I considered this unit here if I could get the money together: http://www.fullthrottlespeed.com/itemdesc.asp?CartId={80EF9EVEREST71E-E6C0-43CF-9484-1D7025A5E543}&ic=050SUPRA3MAFT&eq=&Tp=
Just because it looked similar than maftpro.

Thanks for all your help CRE!! Glad to find someone willing to help, it's always refreshing!

On another note:
I picked up my buddy's rx-7 afm last night and it is a denso unit that looks almost identical to the supra unit. I tested the resistance and everything is well within spec of the supra numbers!

 

[SupraMaster]

OK, well a few people have answered a few different points about this particular unit, but haven't swapped them out with any of the vehicles you have listed as being compatible. I will try this later today. I will put the one from my friend's '88 RX-7 into my Supra and get back to you. I should be able to tell right away as to if it's compatible or not. I will post results either later today, or tomorrow. It just depends on when I wake up; I just got off work, so it will be after noon some time.

Mike

 

[SupraMaster]

Is it possible to replace the thermistor? The more I think about it, the less sure I am of my memory. That is, I do not clearly recall which pins resistance were wrong from this weekend. I will have to check again when I go back to my mother's house where the car is.



Makes sense. Another question for you: Earlier you had said "If the signal scaling matches (ie: 2.50v for a 50% open vane)" and that if the cfms that the unit can flow are different the ecu will not know to respond to less or more air because it doesn't know about it.

Is there any way to really check how many cfm (I am going to do some googling after this and see what I can turn up) and how to check the scaling on the unit?



Quite familiar with both of those, my other project is a 3800 series II and it uses a 3 bar map.



I considered this unit here if I could get the money together: http://www.fullthrottlespeed.com/itemdesc.asp?CartId={80EF9EVEREST71E-E6C0-43CF-9484-1D7025A5E543}&ic=050SUPRA3MAFT&eq=&Tp=
Just because it looked similar than maftpro.

Thanks for all your help CRE!! Glad to find someone willing to help, it's always refreshing!

On another note:
I picked up my buddy's rx-7 afm last night and it is a denso unit that looks almost identical to the supra unit. I tested the resistance and everything is well within spec of the supra numbers!

That's because we share the same stuff. If you have ever unplugged any sensor in the supra you will notice the Denso logo on everything.

 

[jetjock]

A much bigger headache for me would be the inability to have confidence in the car's reliability but it's your call.

Fwiw if the air temp sensor is the only problem with your AFM just run it as is. A lack of THA won't cause a drivibility issue. You won't even notice it and the ECU will take care of the slight mixture offset as soon as the engine warms up. If the MIL/code 24 bothers you add a resistor across THA and E2 that's representative of the typical temperature in your area. 60-70 F will do the job nicely.

That said you may not even get a CEL with a bad THA input since the ECU is programmed to light the MIL only in California cars.

 

[kelner]

A much bigger headache for me would be the inability to have confidence in the car's reliability but it's your call.

Fwiw if the air temp sensor is the only problem with your AFM just run it as is. A lack of THA won't cause a drivibility issue. You won't even notice it and the ECU will take care of the slight mixture offset as soon as the engine warms up. If the MIL/code 24 bothers you add a resistor across THA and E2 that's representative of the typical temperature in your area. 60-70 F will do the job nicely.

That said you may not even get a CEL with a bad THA input since the ECU is programmed to light the MIL only in California cars.

Thanks jj, I think what I am recalling from memory is wrong then, that is it must have been a different pin set, because there are defiantly drive ability issues. Again, I will check to see which one's when I get to my mom's tonight and report back with that and how the rx-7 afm works for me.

 

[jetjock]

Yep, the other part of the AFM (the part that measures air flow) is an entirely different story. If that's bad it'll cause lots of grief. Try another one. Be aware you may have to adjust the idle mixture screw if it's from another model car.