double air flow meter

Hello,

I am currently dealing with a VW Phaeton engine V8 4.2L which uses two seperate air flow meters and I want to use only one air flow meter. Somebody out there who can provide me with some information about air flow meters and if I can divide the signal of one large air flow meter into two signals to substitute the two small air flow meters?

Twiztlock

Reply to
twiztlock
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The twin airflow (or mass airflow, not familiar with your engine) meters are in place most likely for more precise two bank control. Just as the left and right bank O2 sensors report independantly to the ECM, other sensors such as the AFMs also let the ECM know what each bank is doing. The ECM controls injector pulsewidth for each bank separately after processing the main sensors and then trimming that value with O2 sensor feedback data.

You would lose that functionality and performance/efficiency to some degree by using one airflow meter, even if you tricked the ECM into thinking it sees two separate inputs.

Toyota MDT in MO

Reply to
Comboverfish

why wast your time. If the sensor is bad, replace it.

Reply to
jfrancis311

The sensor is not bad, it is just the case that I only have room for 1 air flow meter and I have the intake from a former project which fits on this single air flow meter. Furthermore, it is not an air flow meter for seperate banks, the air flow through either one of the meters and then to a common throtlle house.

I hope someon can give me some help on this, maybe some charateristics of air flow meters?

regards,

Twiztlock

Reply to
twiztlock

I have no idea about the characteristics of the OEM or your MAF, but the hotwire MAF:s used by Ford are highly non-linear. They output a voltage proportional to the airflow, but the non-linearity of them makes it somewhat hard to replace the OEM MAF:s unless you have the ability to reprogram the ECU.

Some are replacing the single Ford MAF with dual MAF:s and tries to use an averaging circuit to provide a the ECU with a proper signal. This is theoretically a problem as flowing twice the amount of air through one MAF does not provide twice the signal, so the proper way is to convert each of the signals into a signal that is linearly proportional to the airflow, which then can be averaged and fed to the ECU, which then needs to have a linear table for converting voltage into airflow.

Going from dual MAF:s into a single is probably easier as you would then only have to wire the single output from the MAF to both inputs to the ECU and then adjust the table(s) in the ECU accordingly. Requires reprogramming the ECU though to work properly.

Reply to
Thomas Tornblom

The Air Flow Meters mentioned are manufactured by Bosch (part nr. small one=0 280 218 060, part nr. large one= 0 280 218 069). Does someone have the characteristics of these ones? Or does someone has experience with Bosch Air Flow Meters and can tell if they always have a linear/non-linear behaviour?

Reply to
twiztlock

Sorry, no idea.

Are the sensors hot air or vane type?

I suggest you call your Bosch rep and ask for technical data. I have called the Swedish Bosch rep and gotten data on various fuel pumps and injectors, and they have been very helpful.

Thomas

Reply to
Thomas Tornblom

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