Problem in my PC-based EFI....

[Frederic Breitwieser]

> 1. A PC with Processor AMD K6 200 Mhz, SDRAM Visipro 32 MBytes.

Overkill, but cool :)

> 2. A disc with 2 hole that fitted on camshaft as a speed sensor and
> position sensor (just for trigger).

For a trigger, its fine.  But if you need to determine cam position,
then you need a lot more holes.  Remember that the cam rotates exactly
1/2 the speed of the crank on a V8 engine, so if you want 1 degree a
hole resolution, you'd have 360 holes on the crank position sensor, and
720 holes on the cam position sensor.  Keep that in mind.

> 3. A Thermistor as a Temperatur Sensor

Why not use a regular every day sensor?  They are very similar.  A
simple pot of cool, then boiling water and an ohm meter allows you to
roughly estimate the value associated with each temperature. Water
sensors as far as I can tell, seem fairly linear.

> 4. A Mass Air Flow Sensor.

MAF is fine.  MAP for forced induction.

> 5. A Throttle Sensor.

Okay.

> 6. Some signal conditionings.

A few op-amps, typically.

> 7. A DAS (Data Acquisition System) Card, that use MAX 180 ACPL

Good choice.

> 8. Parallel Port as an output port to the driver of fuel injectors.
> 9. Driver for fuel injector.

Nothing wrong with this.  You can either use the National Semiconductor
LM1949 injector driver, or use a bi-polar transistor (2n2222 for NPN for
example) driving two IRFII mosfets.  Works well.  I prefer the MOSFET
solution because at the time I started the project, I had a box of them.

> 10. Borland Pascal for writing my software.

Nothing wrong with that either.

> When I start the engine.... everything is working properly, except the
> injectors. It never work, although the leds work. Then I try to slow down
> the injection time (NOT the engine !!! I can do it, as long as it doesn't

What are you driving the injectors with?  You might not have enough
current, too much resistance, etc.  Also, different injectors require
different currents.  Peak/Hold injectors require a surge of current to
open up, and minimal current (but some) to hold it open.

> please contact me if you need further information... you can send mail to my
> personal address, ulet_ijo at yahoo.com

I for one would be very interested in seeing your injector driver
circuit.

-- 

Frederic Breitwieser
Xephic Technology
769 Sylvan Ave #9
Bridgeport CT 06606

Tele: (203) 372-2707
 Fax: (603) 372-1147
Web: http://xephic.dynip.com/
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