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-   -   Air flow meter (https://www.nopistons.com/2nd-generation-specific-17/air-flow-meter-72868/)

rtrypwr98 07-30-2009 10:44 AM

I believe i have a bad air flow meter as when i start the car it fires right up then dies immediately. this is the diagram i have for testing it. Between E2 and Vc I'm supposed to have 200 ohms closed and 400 open well the reading is like 250 closed but doesn't change when the plate is opened. I'm guess this is why it shuts fuel off as it's not getting the signal... Well i ordered a used one and i have same reading across those pins. Any ever test one of these things? Its a freak $1200 part from the dealer and is half the cost of the car i can get a rebuild online for $300 I just want to drive it and havnt in the year i've owned it's just sat while getting put back together. Any help would be greatly appreciated

j9fd3s 07-30-2009 11:25 AM

did you try checking the other side pins? i'm always checking these things backwards



on the s5 afms, resistance starts @200ish, then goes up and comes down a little, dunno why, but it does work when you have the 5v signal across it

rtrypwr98 07-30-2009 11:38 AM


Originally Posted by j9fd3s' post='924912' date='Jul 30 2009, 11:25 AM
did you try checking the other side pins? i'm always checking these things backwards



on the s5 afms, resistance starts @200ish, then goes up and comes down a little, dunno why, but it does work when you have the 5v signal across it







S5 AFM Plug

Turbo and Non Turbo
  • E2 to Vc:
    • plate closed: 200 ohms
    • plate opened: 400 ohms
  • E2 to Vs
    • plate closed: 200 - 1000 ohms
    • plate opened: 20 - 800 ohms
Here is what i've found for the testing. I get 250 closed from E2 to Vc on both E2 pins no change when plate is open but for E2 to Vs i get all the right readings withing range and it changes as the plate opens just no change from E2 to Vc...so i should jumper from connector to AFM and test with the 5v signal to get proper readings?

j9fd3s 07-30-2009 05:37 PM

on the flap side there are three wires, there is a power ground and signal. if you measure power and signal, i think you get the right readings. if you measure power and ground it wont change and ground to signal wont work either



last time i checked an afm, i did put the voltmeter on the signal wire at the ecu. i think key on engine off, is about 5v, idle is 2.5ish and anything over 5000rpms is going to be about 0



or you can just push the thing by hand with the key on.

rtrypwr98 07-30-2009 06:33 PM


Originally Posted by j9fd3s' post='924931' date='Jul 30 2009, 05:37 PM
on the flap side there are three wires, there is a power ground and signal. if you measure power and signal, i think you get the right readings. if you measure power and ground it wont change and ground to signal wont work either



last time i checked an afm, i did put the voltmeter on the signal wire at the ecu. i think key on engine off, is about 5v, idle is 2.5ish and anything over 5000rpms is going to be about 0



or you can just push the thing by hand with the key on.





I think you might be refering to an S4 AFM there are 5 wires to the S5 which is what i have the connector shown on the origional blog...i've never messed with the S4 one

rtrypwr98 07-30-2009 06:34 PM


Originally Posted by rtrypwr98' post='924938' date='Jul 30 2009, 06:33 PM
I think you might be refering to an S4 AFM there are 5 wires to the S5 which is what i have the connector shown on the origional blog...i've never messed with the S4 one

I have a 89 turbo II

j9fd3s 07-31-2009 04:08 PM


Originally Posted by rtrypwr98' post='924938' date='Jul 30 2009, 04:33 PM
I think you might be refering to an S4 AFM there are 5 wires to the S5 which is what i have the connector shown on the origional blog...i've never messed with the S4 one



right, s5 is the two temperature sensor wires, 5v power, ground and the signal. s4 adds the fuel pump switch, which is two more wires.



signal voltage @the ecu is really similar between s4/s5

rtrypwr98 08-01-2009 12:32 AM


Originally Posted by j9fd3s' post='925004' date='Jul 31 2009, 04:08 PM
right, s5 is the two temperature sensor wires, 5v power, ground and the signal. s4 adds the fuel pump switch, which is two more wires.



signal voltage @the ecu is really similar between s4/s5



Alright i will try measuring resistance with it hooked up and see if anything changes

rtrypwr98 08-01-2009 12:35 AM


Originally Posted by j9fd3s' post='925004' date='Jul 31 2009, 04:08 PM
right, s5 is the two temperature sensor wires, 5v power, ground and the signal. s4 adds the fuel pump switch, which is two more wires.



signal voltage @the ecu is really similar between s4/s5



do you know of anything else that would cause my car to start up go to 1500rpm for cold start up high idle and shut off immediately. I'm talking starts and shuts down in 2 sec.

j9fd3s 08-01-2009 10:54 AM


Originally Posted by rtrypwr98' post='925039' date='Jul 31 2009, 10:35 PM
do you know of anything else that would cause my car to start up go to 1500rpm for cold start up high idle and shut off immediately. I'm talking starts and shuts down in 2 sec.



on a t2? sounds like a bad turbo inlet duct... or big vacuum leak


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