This article explains the pros and cons of modern day aftermarket fuel injection systems available for just about any vehicle past or present. In just the past 2 years, the options available have gone from a simple four barrel replacement to dozens of throttle body replacements for almost any type of carburetor. You can find a system that fits your needs at https://www.holley.com/products/fuel_systems/fuel_injection/sniper_efi/. FAST also makes comparable kits.
The Basics
Why it is better!
No Choke! You don't have to set or engage the choke. You don't 'kick it' off fast idle. You don't need to wait for the engine to warm up a little bit.
No float or 'needle & seat' issues - Carbs have long had known problems with float levels and needle & seat problems. If the inlet needle sticks, it can allow the fuel to overfill the carburetor and then leak fuel all over the hot engine. This is a fire hazard and you could lose your entire investment.
Consistency - The engine starts the same way every time. Hot or Cold, the electronics control the idle speed and monitor the engine parameters so that the adjustments are correct every time.
Fuel Mileage - The electronics monitors and adjusts the air/fuel ratio automatically. The ideal (theoretical) air-fuel ratio, for a complete combustion is around 14.7:1. This ideal ratio changes with elevation and weather conditions which the electronics automatically compensates for using EFI.
What are the cons?
IF you ever had & used a 4 barrel carb before, you will remember that familiar 'kick' when you engaged all 4 barrels. It was fun and it gave you a sense of massive acceleration. With EFI, that doesn't happen. Since the computer is controlling the fuel, it simply adds more fuel & air as the throttle is pressed. It is SMOOTH acceleration. No KICK!
Most likely, the fuel pump & tank will need to be upgraded at the same time. This adds an additional $500 or so to the cost of the upgrade. Fuel injection pumps require a pressure around 40 psi or higher while carbs use pumps in the 5-7 psi range. In addition to this extra pressure, un-used fuel is usually routed back to the fuel tank by means of a return line. This can cause turbulence in the tank which in turn can cause cavitation in the fuel pump supply. To prevent this, EFI tanks have baffles that prevent this from happening.
It is also recommended to use an in tank pump. Cavitation is less likely and the pump operation is much quieter when using in-tank fuel pumps. The good news is, you can find complete tank kits to fit almost any vehicle from Holley or Tank's Inc.
What's Involved?
1rst, get the fuel system ready. Install 2 fuel lines, a supply and return line from the tank to the old carb area. This line & connecting hoses MUST be rated for fuel injection purposes. If you are installing a new tank with in-tank pump, install the tank and then install the correct in-line fuel filters.
The EFI KIT is amazing. You need a power wire, and you need to add a 'bung' to the exhaust for an O2 (OXYGEN) sensor and install the temperature sensor. The rest of the sensors (throttle position, IAC (throttle control), Baro, fuel pressure regulator ) are all part of the UNIT (TBI). Bolt the unit on, connect the fuel lines, and the EFI controller will start the AUTO-calibration. That is it!
IF you have additional questions or would like a quote for your vehicle, please text, email or give me a call anytime!
Stay tuned for my article on Ethanol, fuel mixes delivered to the pumps and how it affects your car, plus venting and fuel expansion problems.
Copyright 2019 Rick Rossi / Moparresto You may copy and/or forward this document in it's entirety only.