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

[Chris Ice]

mike wrote:
> 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,

No, no....the hot wire maf is seeing 1.0v at idle.  If I take the hot 
wire out, and put the vane-style AFM back in...it reads 3.2v at idle. 
The signal conditioner is mapped, and takes input volts (1.0) times a 
multiplier (1.6) plus a constant for each rpm to recreate the appearance 
of a vane style afm for the ecu.

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

For the existing vane style meter, I have this:

http://www.trub.com/index.cgi?cars/lancia/beta_efi_wiring.pdf

For the signal conditioner, I have this:

http://www.splitsec.com/products/datapdfs/PSC1-009.pdf
[ref pg 2]

Am trying to hook #2 into #1.

> 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.

Again, mine is a 5v afm system, so 3.2v at idle is fine....and the 
signal conditioner can recreate that same 3.2v using a 1.0v input from 
the hot wire.

The problem is, per the "beta_efi_wiring.pdf" above, I don't know what 
to do with pins 8 and 9.  Leaving them unconnected seems to not be an 
option.

Chris


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