[Diy_efi] What Injector Is This?

[Perry Harrington]

Mike,

200C is 424 degrees farenheit.  That is really damn hot.  Consider
also that it's above ambient.  If it's 100 degrees ambient, that element
is 524 degrees.  That is about like a soldering iron.

The bosch MAFs don't get nearly that hot, that's why they have a burn
off pulse.

The Ford MAFs are dumb, they have no external "burnoff" signal.  The
circuitry inside is just the driver and calibration.

I have not looked inside the MAF at poweroff.  The MAF is directly
powered via 5v from the ECU, it doesn't have an external power.  When
the ECU powers down the MAF loses all power.

--Perry

On Fri, Apr 04, 2003 at 11:40:04AM +0800, Mike wrote:
> At 12:14 PM 4/3/03 -0800, you wrote:
> >My Probst book has a blurb about the MAF, I'll fine the schematic
> >of it elsewhere.
> 
> Great, I'm interested in alternatives,
> 
> >The cold wire which is not exposed to the air stream is not heated,
> >it simply is a thermister.  The Hot wire is heated to 200C above
> >ambient, so you can see, it's always very hot.
> 
> Yes true, I have the old Bosch yellow book from 1982 same mostly,
> 
> I'm curious if you have ever looked down the throat of the AFM
> when powering off etc ?
> 
> rdgs
> 
> mike
> 
> 
> 
> 
> >--Perry
> >
> >On Thu, Apr 03, 2003 at 07:36:22PM +0800, Mike wrote:
> >> Its very similar, the bosch element in mine is not
> >> that small - looks like the wire length is some 60mm
> >> arranged in a loop.
> >> 
> >> I dont think its a design issue (read flaw) wich means
> >> the Bosch 'needs' a large clean current as might be
> >> implied. Bosch seem to go to some trouble with
> >> issues like cal and an automatic clean as such is
> >> bound to be more reliable than relying on people to
> >> do it - which I still find perplexing.
> >> 
> >> Have you ever looked into the throat of one of these
> >> ford MAFs and watched if it does or doesnt apply a
> >> current pulse - maybe it does but its not enough to
> >> make the wire glow.
> >> 
> >> Yes, I would like to see a schema of the ford MAF,
> >> the 'clean' may well be supplied by the ecu and not
> >> be inherent in the MAF as it is for bosch, as far
> >> as I can determine from all I've read on these
> >> issues - some sort of 'clean' burn is very helpful...
> >> 
> >> rgds
> >> 
> >> mike
> >
> >-- 
> >Perry Harrington			Data Acquisition & Instrumentation, Inc	
> >perry at dainst dot com					 http://www.dainst.com/
> >
> >Those who would give up essential liberty to purchase a little temporary
> safety
> >deserve neither liberty or safety. Nor, are they likely to end up with
> either.
> >                             -- Benjamin Franklin
> >
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-- 
Perry Harrington			Data Acquisition & Instrumentation, Inc	
perry at dainst dot com					 http://www.dainst.com/

Those who would give up essential liberty to purchase a little temporary safety
deserve neither liberty or safety. Nor, are they likely to end up with either.
                             -- Benjamin Franklin

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