DeLorean Fuel Flow Measurements

["drdhdmd <doctordhd@xxxx>" <doctordhd@xxxx>]

OK after thinking about it some more, I agree that using the 
frequency 
valve data, is not the way to go. ? I imagine that it only trims the 
fuel pressure and therefore the flow to maintain a closer match for 
the air fuel ratio. ? After all Bosch has a system just like ours 
that 
does not use a frequency valve at all.

That HAL401 looks interesting and they are sending me some samples. ? 
The only thing I don't like is that you have to add the weight of a 
magnet to the air flow plate. ? This may throw off the mixture. ? For 
a 
given air flow, the plate will have moved down a bit more than it 
used to and, if I understand the system properly, will cause a higher 
pressure and thus more fuel to the injectors. ? Ah, yes but the 
Lambda 
sensing this should let the frequency valve do a bit of 
compensation. ? Will it be enough? ? Another thing is what happens 
when 
the magnet falls into the intake manifold. ? (Hey I'm a firm believer 
in Murphy's Law.)? Which bring me to the following question. ? Does 
anyone know what the 10 mm bolt that holds the air flow plate to 
the 'arm" is screwed into? ? Is there a nut on the underside or is 
the 
arm tapped. ? I would hate to unscrew it and have the nut fall into 
the intake. ? Does anyone have a better diagram of the "mixture 
control unit "? that would answer that question? ? Maybe someone 
already 
has taken one of those things apart and knows. ? I suppose if the arm 
were tapped the you could carefully remove the bolt and washer and 
maybe magnetize the screw. ? I believe both the screw and the washer 
are made of magnetizable metal, i.e., steel.

Another way to go might be a reflective optical sensor, I ordered one 
from www.allelectronics.com, one of my favorite parts suppliers The 
part is a Vactec 21L900.? All Electronics, has some really small and 
very powerful neodymium magnets, too

In the interim, I am still waiting to receive the AUDI 5000 trip 
computer I won on ebay. ? As I mentioned before, I read info on the 
net 
that the AUDI Bosch system has a potentiometer attached to the air 
flow plate pivot and uses that for the trip computer sensor. ? Can we 
do something like that? ? I also tried to build a solid state 
anemometer. ? I found the response to an air flow was good but when 
the air stopped it took too much time to settle down. ? It uses a 
plastic transistor as itts sensor. ? I built it because I believe 
that 
some OEMs use an anemometer setup to measure air flow, i.e. the AIR 
MASS SENSOR. ? They usually use a "hot wire technique" which I could 
not find a circuit for other than a block diagram. ? The sensor of a 
hot wire system is also usually very fragile, but I would imagine 
much more responsive. ? I did read about a circuit that used the 
filament from a light bulb, with out the glass envelope, but I could 
not find the circuit. ? Hey is there a word limit on posts? ? 

Eagerly, awaiting your responses,

Dave & 6530