Are all TBI injectors the same?

The actual throttle plate diameters for the 4.3/5.0/5.7L TBI units are all the same at 111/16 inches (big-block TBIs are 2 inches). The difference is the injector flow rates. The 5.0L injectors flow 40 to 45 lb/hr, the 5.7 ones are 50 to 55 lb/hr, and the big-block injectors flow around 75 lb/hr.

What do the numbers on fuel injectors mean?

Fuel Injectors are sized by their flow rate. Flow rate is a measurement of how much fuel can be delivered over time. It is listed in pounds per hour (lbs./hr.) or cubic centimeters per minute (cc/min.). The right size injector can supply enough fuel under full load conditions at an 80% duty cycle.

How do I know what size injector to get?

So to figure out what size fuel injector will result in an 85% duty cycle, divide the original result by 0.85: 18.75 lb/hr/0.85 = 22 . 1 lb/hr requirement. Since the next popular injector size available is 24 lb/hr, this is the correct size injector that you should choose for this particular application.

What does TBI stand for?

Traumatic Brain Injury / Concussion.

What happens if injectors are not coded?

Non start – In newer systems if you do not code in the injectors the vehicle will not start. Poor / lumpy running – as the injectors are not coded, the ECU will carry on fuelling as if the previous injector was still present, which can cause poor performance.

Can you run too big injectors?

It’s easy to fall into the trap of thinking that bigger fuel injectors equal more power, but unless your engine is set up to deal with the extra fuel, you’ll be on a fast track to trouble. The excess fuel will flood the engine and it either won’t run at all, or will be running too rich.

Are all injectors compatible?

If the body of your car’s injectors is gray, keep in mind: injectors of all releases ARE compatible! So, your car can have injectors with a different release for each cylinder!

Does a TBI have a fuel pressure regulator?

Second only to the stock TBI ECM, the stock TBI fuel delivery system leaves a lot to be desired. Starting at the tank the fuel pump is a turbine pump. Quiet and long lasting, but weak fuel delivery. The fuel pressure regulator is set for approximately 12 psi (30 psi on ’94 & ’95 BBC trucks).