Accel/dfi – Mallory Ignition ACCEL CHEVROLET APPLICATIONS (including LT-1) 74022 User Manual

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ACCEL/DFI

ACCEL/DFI has a number of fuel injection manifolds
for small block and big block Chevrolets available. With a
growing selection of manifolds, ACCEL/DFI should be able
to satisfy almost any engine combination. For the
combinations that would not be satisfied by our proven
manifold designs, including applications not covered,
ACCEL/DFI has the hardware necessary to modify a carbu-
reted style intake for multi-port injection. Contact a dealer or
reference our catalog for part numbers. ACCEL/DFI also has
Engine Management Installation Centers (EMIC) that can not
only install and tune your system but many can also fabricate
or modify an intake for you as well. For the nearest EMIC to
you call: 1.800.992.2235.

Prior to installing your manifold make sure that gasket
surfaces are clean. ACCEL recommends using a 180 degree
thermostat. Place your thermostat and gasket onto your
manifold, put your thermostat housing onto the manifold
and bolt in place. If your are using TPI manifold, whether it
is stock or an ACCEL unit, you will have to place the injectors
into the fuel rail and bolt them onto your manifold before
you bolt the runners and install the injector harness. Be
careful when installing the fuel injectors so as not to cut the
O-rings. A small amount of oil on each O-ring will aid in the
assembly. If you are using a factory 1985-89 plenum you will
need to plug off the Cold Start Injector port, use ACCEL/DFI
part number 74820 to do this.

NOTE:

It is recommended at this point to use a

hole saw (i.e.: Green Lee punches) to put two (2)
1-5/8” diameter holes in the firewall to
accommodate the main wire harness. Refer to
Figure D for hole locations.

Prior to bolting the throttle body to the plenum, we rec-
ommend cleaning the throttle blade, bore, IAC pintle and
seat area. Depending on the age and prior use of a used
throttle body, a significant amount of gum can accumulate in
these areas and affect the idle characteristics of the engine.

Plumbing Connections:

A vacuum line must be attached between the fuel
pressure regulator and the right rear side of the plenum.
Do not splice into this vacuum line; this can promote an
erratic vacuum signal.

Use a 7/16” diameter hose to connect the oil breather on
the valve cover to the right side of the throttle body, if so
equipped. If not plug the corresponding port off on the
throttle body.

Use a 5/32” diameter vacuum line from the bottom of
the throttle body to the vacuum advance canister on the
distributor. This is a ported vacuum signal. (This is only
used with non-computer controlled HEI ignitions).

On the left side of the base manifold (on factory TPI and
ACCEL base manifold) a barbed fitting is located. Use a
3/8” PCV hose to attach this to the PCV valve on the left
valve cover. If you will not be using this, plug the barbed
fitting.

Install a 3/8” diameter vacuum line from the rear
barbed fitting on the plenum to the brake booster unit.

Finally, use a vacuum line to connect the MAP sensor to
the right rear plenum fitting. Make sure not to splice into
the MAP sensor vacuum line, this could promote
inaccurate sensor readings.

II – SETTING UP YOUR MANIFOLD

I – OBTAINING YOUR MANIFOLD