[Diy_efi] Bosch L-Jet AFM question...

[Mike]

On my AFM there is an adust pot at that could be the 7v you see,

Also on my AFM (Hot wire MAF) the output voltage at idle is
around 1.6v, so your 3.2v seems a bit high,

Just to be sure, the pin outputs you describe below, are these
for the old AFM or the new one MAF (hot wire one) ?

Because if its for the new one then 3.2v is way too high for
normal MAF output at idle and if its the old one then the ECU
will need to log multiply to get the same effective air flow,
either way - I think you will need to retune the maps in your
ECU, especially if the old AFM was a vane type because those
outputs were not always log, some were linear afaik.

rgds

mike



At 07:16 PM 4/1/03 -0800, you wrote:
>I'm very confused by something and I'm hoping someone can clarify...
>
>Am attempting to replace the AFM with a MAF sensor (using a signal 
>conditioner)...and am not sure how/where to send the voltage.
>
>Pin 6 - as far as I can tell is ecu ground
>Pin 7 - afm signal voltage to ecu (at idle, 3.2v across 6&7)
>Pin 9 - 12v supply (w/o car running)
>Pin 8 - what the frick is this?  7.6v?
>(36/39 = fuel pump, 27&6 is air temp...those are easy)
>
>If I simply send signal down pin 7 (leave 8 and 9 disconnected), the ecu 
>is clearly unhappy with this and just dumps gas pretty much w/o regard 
>to the signal voltage on 7.
>
>I've read in various places that the afm voltage is corrected for dips 
>in battery voltage.  If I put a 200 ohm resistor between pins 8 & 9, I 
>can get the car to run, but it's now way lean.
>
>Anyone have any insight into the relationship between these 4 pins?  If 
>I plug the afm back in, it's all magic...3.2v between 6&7.  But put 3.2v 
>down 7 w/o 8&9 and chaos ensues.
>
>Chris
>-- 
>Chris Ice                    "Laugh'a while you can, Monkey Boy."
>http://www.trub.com/                               - Dr. Lizardo
>
>
>
>_______________________________________________
>Diy_efi mailing list
>Diy_efi at diy-efi.org
>http://www.diy-efi.org/mailman/listinfo/diy_efi
>
>

_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://www.diy-efi.org/mailman/listinfo/diy_efi