DIY_EFI Digest V4 #568

[rpettibo at hpubs.com]

This conversation is very interesting to me because I rely on a wide array
of sensors on my project and find that each one is necessary.  I hope
people do not try to invest in fuel injection with the tought of keeping it
simple will keep it cheap and then I can aford to upgrade.  I think this is
the wrong approach to fuel injection.  My experience is it cost MONEY to do
it and do it correctly.  The question is not so much how complicated does
EFI have to be but how sophisticated.  None of these sensors or triggering
devices for fuel or spark management is that complicated.  The value  of
them is in the ECM's ability to read them and through precise programming,
by you or the computer defaults, modifying the fuel and spark events for
best power and torque.

If you truly want it simple, put on a 3310 Holley.  If you want the
benefits of injection spend the money and the time to install all relevant
sensors, have the ability to monitor and record them, spend the time
understanding what they are telling you and utilize this data to dial in
the system.  This is the area you will spend the most time and effort in
and it will be worth it.  Be sure you also invest in systems which allow
you to directly interface and change programming in the computer.  Based on
your sensor data, RPM, LOAD (VAC), THROTTLE POSITION, O2 READING, H2O TEMP
AND INLET AIR, you will be able to dial in your system at that point of
engine operation.  To dial in a fuel injection system you may have to dial
in as many as 256 fuel and spark map points for proper operation.

As a side note the most valuable tool I invested into my EFI project (515
hp, 535 lb-ft  sb Chevy) is an EGT system from Autometer.  I monitor at
least two cylinders at all times and record all peaks.  The differences
between being 10% lean or rich and on the money are definitely worth the
price of admission.

Invest the money and time to do it right.!!!!