Installing Extra Fuel Injectors
This page describes how to install extra fuel injectors to increase the
fuel supply to your engine. There are a few reasons why you may be
doing this, but the primary reason is because you have modified your system
such that the ECU does not know or is not able to add enough fuel to maintain
a safe air/fuel ratio. One way to do this is to install one or more
cold start injectors near the throttle body. This concept was developed
by Gus Mahon, and is detailed on his web site. Cold start injectors
are used primarily on European vehicles (Saab, Volvo, VW, etc) that are
equipped with mechanical fuel injection and the Bosch fuel control system.
Another, more complex way, is to install one or more electronic fuel injectors
and control it with a fuel injection control module. This module
pulses the fuel injector the same way that your ECU pulses your current
Cold Start Injectors
The cold start injectors need to be controlled so that they turn on when
needed. This can be done one of two ways. If you are only installing
one injector, then the easiest way is to use a pressure switch. This
procedure is detailed by Gus Mahon. If you are installing more than
one injector using this method, then you need to install a pressure switchfor
each one. An alternative is to use an Electronic
Engine Performance Controller to control up to four injectors.
The downside to this is that you have to have a MAP sensor that can read
the manifold pressure up to the level that you need. This can be
done by installing a secondary 3-bar MAP sensor, or by bleeding a stock
MAP sensor. The links below take you to the pages that provide all
the details. Gus's page holds all of his adding fuel tricks, so you
should definately look at that. I have broken down all of the information
into seperate pages, which should help you if you are confused.
by Gus Mahon (skip to the 5th section)
Controlling Cold Start
Injectors With A Pressure Switch, by Russ W. Knize
Controlling Cold Start Fuel
Injectors With The EEPC, by Russ W. Knize
Electronic Fuel Injectors
Installing electronic fuel injectors is somewhat more complex. Aside
from figuring out how to mount them, you also have to control them.
There are controllers available for doing exactly this, which even come
with the injector(s) and mounting hardware. I have designed a cheap
controller that you can build and use to control your own extra injectors.
This controller can also be used for alcohol and water injection as well.
I have not been able to build or test it yet, so this information will
not be available for some time.
Links to fuel injection kits coming soon...
This page is maintained by Russell W. Knize and was last updated 04/22/99.
Comments? Questions? Email
Copyright © 1996-2003 Russ W. Knize