IGNITION COIL
The Pro Flo 4 EFI system has an internal coil driver capable of direct firing an inductive ignition coil. An inductive coil alone will support most applications without the need of a CDI box. Edelbrock ignition coil part #22746 is recommended. The following is a list of alternative coils that have been validated by Edelbrock to work well with the Pro Flo 4 system:

MSD Blaster 2 #8202
MSD Blaster 3 #8223
MSD Street Fire #5524
Pertronix Flame-Thrower #40111
Bosch "Blue Coil" #9220081083
Jegs High Energy Ignition Coil #40105
Summit Racing High Output Coil #G5215
Summit Racing High Output Coil #G5219










If not using a coil from this list, ensure that the coil’s primary resistance is at least 0.6 Ohms and inductance is at least 6.0mH. Pro Flo 4 can NOT directly fire low resistance, low inductance coils that are intended for use with a CDI box otherwise severe damage may result. If choosing to use a CDI type coil, a CDI box must also be used. Damage caused by improper coil selection is not covered under warranty. A CDI box is recommended for high horsepower and high rpm (>6,500 rpm) engines.

Note that Edelbrock ignition coils part #22740, #22741 & #22742 are intended for use with the Edelbrock Max-Fire distributors only and are NOT compatible with the Pro Flo 4. Using these coils with the Pro Flo 4 may damage the system.

Edelbrock 22746 canister coil: https://www.edelbrock.com/shop/ignition.html

Example of an UNACCEPTABLE coil that will damage your Pro Flo 4 ECU is the MSD 8207 Blaster SS coil: https://www.holley.com/products/igni...ils/parts/8207 Its primary resistance is 0.355 ohms and is below the minimum primary resistance spec.

Please note that coil selection is not trivial and coil specs should be checked before attempting to use with the Pro Flo 4 system. If you have questions, call Edelbrock EFI Tech Support at 1-800-416-8628. Damage caused by improper coil selection is NOT covered under warranty.

FUEL PUMP
As per the instructions, "The maximum current for the fuel pump is 10 amps. If the fuel pump current will exceed 10 amps, a fuel pump relay is necessary".

The Pro Flo 4 EFI system wiring harness is configured so that 12v power to the fuel pump is provided by the main relay. This means that the fuel pump power is on whenever the ignition switched is turned on to have the ECU powered up. The ECU turns the pump on and off by controlling a ground output. Pro Flo 4 does NOT use a switched 12v power source to turn the fuel pump on and off. The pump is turned on and off by a switched ground.

Acceptable fuel pumps that would not require a relay include the Edelbrock in-line 255 LPH EFI fuel pump part #3594 or Walbro GSL394 & GSL392 (190 LPH & 255 LPH) or equivalent which can support 500-600+ horsepower. These pumps operates below 10 amps of current when ran at either 43 or 58 psi of fuel pressure.

Example of UNACCEPTABLE fuel pumps to power directly from the ECU would be high performance, aftermarket "Bosch 044 style" pumps. These higher output pumps typically draw 12-15 amps during normal operation and would require a relay.

Please note that fuel pump selection is not trivial and pump specs should be checked before attempting to use with the Pro Flo 4 system. If you have questions, call Edelbrock EFI Tech Support at 1-800-416-8628. Damage caused by improper fuel pump selection is NOT covered under warranty.

Note that because of the way Pro Flo 4 is configured to control the fuel pump (constant 12v, switched ground), in-tank fuel pumps that are permanently grounded and powered by switched 12v will either need to be re-wired or a relay will need to be added.

If converting a carburated engine over to EFI, it's mechanical fuel pump can be retained and used to supply fuel to the Edelbrock EFI Fuel Sump: https://www.edelbrock.com/adjustable...psi-36031.html Note that the Fuel Sump includes a fuel pump power connector that plugs right into the fuel pump power wiring lead connector in the Pro Flo 4 wiring harness for a plug-and-play connection.