INSTRUCTION
MANUAL
FOR
CHEVROLET APPLICATIONS
(including LT-1)
www.accel-ignition.com
ACCEL/DFI
Installation Manual For The ACCEL
Digital Fuel Injection Engine
Management System
Prior to starting the installation of your ACCEL/DFI system, read this manual carefully!!
Contents |
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Number |
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
. . . . 2 |
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I) |
Obtaining Your Manifold . . . . . . . . . . . . . . . . . . . . . . . |
. . . . 2 |
II) |
Setting Up Your Manifold . . . . . . . . . . . . . . . . . . . . . . . |
. . . 3 |
III) |
Mounting Your ACCEL ECM . . . . . . . . . . . . . . . . . . . . . |
. . . 3 |
IV) |
Injector Harness Installation . . . . . . . . . . . . . . . . . . . . . |
. . . 4 |
V) |
Main Wire Harness Routing and Connections . . . . . . |
. . . 4 |
VI) |
Choosing Your Distributor . . . . . . . . . . . . . . . . . . . . . . . |
. . . 5 |
VII) |
Fuel Pump Mounting and Fuel Line Installation . . . . |
. . . 6 |
VIII) Mounting The Oxygen Sensor . . . . . . . . . . . . . . . . . . . . |
. . . 8 |
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IX) |
Air Cleaner Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . |
. . . 7 |
X) |
TPS Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
. . . 9 |
XI) |
Starting the Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
. . . 9 |
XII) |
Optional Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
. . . 10 |
XIII) |
Trouble Shooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . |
. . . 11 |
Some parts are not legal for sale or use in California or on any pollution controlled motor vehicle.
INTRODUCTION:
ACCEL/DFI
CONGRATULATIONS! You have just purchased the finest engine management system available. Fuel injection control is an exact science that ACCEL has made simple. This manual is written to assist you with the installation of your new system. Please read the manual carefully.
Prior to starting your installation, please verify the contents of your ACCEL/DFI package. You should find the following components:
Electronic Controls Module (ECM)
Main Wire Harness (MWH)
Injector Wire Harness (IWH)
Manifold Absolute Pressure (MAP) sensor
Heated Oxygen Sensor with mounting nut
Coolant Temperature Sensor (CTS)
If you are missing any item, please contact your dealer immediately.
Although the package you just received is designed to allow you to convert a carbureted engine to fuel injection or allow you better control over your present fuel injected engine, it does not include the hydraulic portion of the installation. If you need a fuel pump, filter, fittings, etc. Contact your ACCEL EMIC center for the proper ACCEL/DFI part numbers for your application.
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ACCEL/DFI
I – OBTAINING YOUR MANIFOLD
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 carbureted 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.
II – SETTING UP YOUR MANIFOLD
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.
ACCEL/DFI
Prior to bolting the throttle body to the plenum, we recommend 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)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.
b)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.
c)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).
d)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.
e)Install a 3/8” diameter vacuum line from the rear barbed fitting on the plenum to the brake booster unit.
f)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.
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ACCEL/DFI
III – MOUNTING THE ACCEL ECM
The ECM comes with three (3) mounting tabs designed for a #8 sheet metal screw. It is recommended to mount the ECM in the passenger side kick panel. If the kick panel has an air vent incorporated into it, DO NOT mount the ECM here. This is not waterproof and therefore, needs to be mounted in a location free of moisture. The alternate location is in the dash board area behind the glove box. NEVER MOUNT THE
ECM IN THE ENGINE COMPARTMENT!
IV – INJECTOR HARNESS INSTALLATION
It is strongly recommended that this harness be installed prior to mounting the plenum. Refer to Figure A for routing the injector harness.
This ACCEL/DFI system is simultaneous double fire, therefore, an injector connector may be connected to any injector, but for your convenience, the connectors are paired in two’s, similar to the way the injectors are mounted in the manifold.
Route the injector harness onto the manifold as shown in Figure A (Page 22). After properly aligning the injector harness onto the injectors, clip the connectors into place, making sure that the metal clips snap into place. After the main wiring harness has been installed, connect the injector harness round 5-pin female connector to the MWH’s round 5-pin male connector.
ACCEL/DFI
V – MAIN WIRE HARNESS ROUTING
AND CONNECTIONS
An overview schematic of the main wiring harness (MWH) is shown in Figure B (Page 23). The harness can be routed and connected as follows: Begin by connecting the 32 pin and 24 pin ECM connectors to the ACCEL/DFI ECM, making sure that the tabs snap into place. Then route the longer of the two legs through the drivers side firewall hole that you cut in step two, followed by the shorter of the two legs though the passenger side firewall hole. Continue pulling the harness legs through the firewall until the rubber grommets seat themselves in the firewall. Once the grommets have been properly seated into the firewall, each leg of the harness can be routed between the manifold and the valve covers.
The drivers side leg will contain connectors for the following:
•MAP (3-pin green male connector, refer to Figure B for mounting location)
•Computer controlled HEI (4-pin male black connector)
•ESC (1-pin female black connector)
•Air (2-pin Grey connector)
•Coolant (2-pin black connector)
•TPS (3-pin black male connector)
Connect each to the appropriate sensor using Figure B as a reference. If this is a ACCEL system for an LT-1 engine (74022-L), there will be an Opti-spark harness that will connect the Computer controlled HEI connector, a TPS extension harness, IAC motor adapter as well as adapter harnesses for the air and coolant sensors. If you are missing
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ACCEL/DFI
any of these harnesses please contact your dealer immediately. Make sure to connect the switched +12 volt wire (long pink wire with a female spade connector) to a switched ignition accessory in the fuse box. The switched ignition accessory must maintain 12 volts during cranking, if it does not the vehicle will not start.
NOTE: If you are not controlling timing with the ACCEL/DFI ECM (using a non-computer controlled HEI, points distributor, etc.) you will not be using the computer controlled HEI connector (4-pin male black connector) or the ESC connector (1-pin female black connector).
The passenger side harness leg will contain the following sensor connections:
•Oxygen (3-pin female black connector)
•Injector (5-pin round white connector)
•Tach pick-up (1-pin brown connector)
•Fuel pump (bare lead, red wire with white stripe)
•IAC (4-pin square male black connector)
Connect each to the appropriate sensor using Figure B as a reference. If you need to lengthen the fuel pump wire to reach your fuel pump, make sure to use at least 14 gauge wire. Finally, be sure to connect both the positive and ground terminals of the MWH DIRECTLY to the battery. If you fail to do this intermittent and unusual problems may occur.
NOTE: If you are controlling timing with the ACCEL/DFI ECM (using a computer controlled HEI, TFI, etc.) the Tach pick-up will not be
ACCEL/DFI
used. If you connect the Tach pick-up and the Computer controlled HEI connector at the same time, your ECM will cancel both of them out, resulting in a no spark situation. In many cases this will also damage your ECM.
At this time you can connect your User Interface Module (UIM, or Power Tuner) to the MWH by connecting the 6-way connector (located near the ECM connectors) to the 6-way connector on the UIM. If you did not order a UIM there is nothing for you to do with the 6-way connector on the main
harness. |
If using a UIM, mount the unit with two (2) |
#8 sheet |
metal screws or pan head screws with nuts, |
in a location convenient to the driver. See section XII for description.
VI – CHOOSING YOUR DISTRIBUTOR
NON-COMPUTER CONTROLLED IGNITION
If you are using a non-computer controlled HEI (prior to 1985), points style distributor, etc. the Tach pick-up (1-pin brown connector) must be used. Connect this lead to the negative side of your coil. If the brown connector must be removed for your application, be sure not to remove the 39K ohm resistor which is 3” from the existing connector.
NOTE: If you are using an aftermarket ignition enhancer box (i.e.: ACCEL 300+, MALLORY Hyfire) the MWH’s Tach pick-up connector MUST be connected to the enhancer box’s Tach output signal. It is also necessary to remove the 39K ohm resistor from the Tach pick-up wire. It is 3” from the end of the Tach pick-up lead. DO NOT connect this lead to the negative side of your coil if using an enhancer box, this can result in ECM damage.
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ACCEL/DFI
ACCEL strongly urges the use of a good quality suppression wire such as ACCEL 300+ or ACCEL RFI Suppression Wires. We have encountered problems with various ignition wires available on the market such as helically wound or solid core not suppressing electrical noise. The use of these wires may interfere with the operation of the ECM. Further, some high energy aftermarket ignition units also produce electrical fields which will interfere with the ECM’s operation. Use of these units is strictly at the risk of the owner. Call ACCEL for recommendations of ignition system compatibility.
The total advance you set the engine to will depend upon the engine you have. Vacuum advance should be controlled with the EGR port, which is located on the bottom of the throttle body. ACCEL/DFI recommends a distributor with adjustable vacuum advance. Once the total advance is set, connect the vacuum advance canister. Adjust the vacuum advance canister to maintain 20-26 degrees with a hot engine at 800 RPM. Again, this is ACCEL’s recommendation, depending upon the compression ratio and cam profile, you may have to decrease timing to avoid detonation.
COMPUTER CONTROLLED IGNITION
If you are using a GM (F or Y body) computer controlled HEI distributor the MWH’s four pin male black connector must be used. When using a Y body HEI , the four pin between the HEI and the MWH is compatible. However, if you are using a F body HEI, the four pin connection on the MWH will not plug directly into the distributor. In order to use a F body HEI you will need additional wiring. ACCEL/DFI’s part number 74170 will allow you to connect your distributor to the MWH. You can also control timing with the ECM by using a magnetic pick-up distributor or crank trigger. In order to control timing with these ignition systems you
ACCEL/DFI
must get a modification done to your ECM (ACCEL/DFI part number 74043-I), this modification will come with the necessary additional wiring, but will not come with an ignition enhancer box that is required. If you will need this modification contact ACCEL/DFI for further instructions and a shipping address.
In order to set the initial timing, the ignition bypass connectors (white-one pin connector), incorporated into the HEI leg of the main wiring harness, must be disconnected. With the engine running hot at 800 RPM, manually adjust the distributor to 6 degrees BTDC. Once adjusted, reconnect the ignition bypass line. As soon as you connect the bypass line the timing will then be controlled by the ECM. The spark curve is preprogrammed into the ECM from ACCEL/DFI. It has as initial timing of 20 degrees BTDC and a total timing of 34 degrees BTDC in by 3000 RPM. The timing curves, as well as all other tables in the ECM, can be adjusted to better suit your engines requirements using ACCEL/DFI’s calibration software CALMAP.
NOTE: If an aftermarket ignition enhancer box is used (i.e.: ACCEL 300+, MALLORY Hyfire) the Y body HEI can be wired as described by the manufacturer. However, if you are using an F body HEI or controlling timing with a magnetic pick-up distributor or crank trigger please reference figures E and F.
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