What should fuel pressure be on a TBI fuel injection system?

Fuel Pressure is critical to the operation of a fuel injection system. Always check to insure that you have the proper fuel pressure. Fuel pressure should be a constant 10 – 15 PSI on a TBI fuel injection system and is typically around 12 – 13 psi. Higher pressure than 15 psi indicates that there is an issue with the installation.

Why is my fuel injection system plugged in?

The electric fuel pump installed for a fuel injection system will draw considerable more volume of fuel from your tank than your old system did. If there are any contaminants in the tank this many times will plug up or greatly restrict the flow of fuel to the system causing many issues. Step by Step Troubleshooting guide.

What is the TBI code on a 1990 Chevy truck?

Consult a service manual or see below for any check engine light code definitions. You can use a late 80’s or early 90’s GM TBI definition. If you have access to a scan tool use a hook up for a 1990 350 cu. in. 5.7L Chevrolet truck. For some scan tools enter VIN 10th“L” 3rd“C” 8th“K”.

Can a TBI be used as a return line?

These fittings are not suitable to use as a return line because they have an orifice in them and restrict the flow of fuel back to the tank. If you have installed your return line to a “vent” line you will need to route the return line in a different fashion. Fuel pressure on a TBI unit should stay constant under all throttle conditions.

What causes a vacuum leak in a fuel injection system?

Vacuum leaks are the leading cause of installation issues with your fuel injection system. Check all sources of potential vacuum leaks including components not related to the fuel injection system. There are instances where the vacuum leak is coming from the adapter plate used to attach the throttle body to the manifold.

Why is there no fuel spray from injector?

On the way home it stopped and hasn’t run for weeks now. There is fuel and pressure at the injector but no spray. There is a red wire and blue wire there. The red has 12 volts, the blue is supposed to pulse on cranking. It does not pulse.

What kind of scan tool do I need for GM TBI?

A scan tool can be used and set up for a GM TBI application to read the data, or to check for stored codes. Consult a service manual or see below for any check engine light code definitions. You can use a late 80’s or early 90’s GM TBI definition. If you have access to a scan tool use a hook up for a 1990 350 cu. in. 5.7L Chevrolet truck.

How to test for fuel spray during crank?

This is to be an ignition 1 (ING1) source which is power in both the key run and crank position. Correct the connection of this wire and verify voltage to the pink wire on the injector connector. Test again for fuel spray during crank. If the engine still cranks, is spraying fuel, but will not start go to step 2.

Where does the vacuum leak come from on a TBI?

There are instances where the vacuum leak is coming from the adapter plate used to attach the throttle body to the manifold. If this is the case make sure that the seal is positive between the manifold and the adapter plate; also between the adapter plate and the throttle body.

What causes no power to fuel injector pulse?

Ans: The engine control unit is the electronic brain that used to control the fuel injector pulse by gathering data from various sensors along the fuel line Question: What causes no power to fuel injectors?

How does the engine control unit control the injector pulse?

Question: What controls the fuel injector pulse? Ans: The engine control unit is the electronic brain that used to control the fuel injector pulse by gathering data from various sensors along the fuel line

Why is there no pulse from the injector?

Used all original electronics and tbi. New wires, plugs, cap, rotor, fuel filter,etc… have spark, have fuel at the back of the tbi. No pulse at all from either injector?

What kind of signal does a GM injector pulse have?

Purple/white wire with key on had barely any signal at all. Wires to the injectors have 12v with key on. I have fuel at the rear of the tbi but not sure of the pressure?

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