How does the CPI fuel injector system work?
How does the CPI fuel injector system work?
Dubbed Central Port Injection, or CPI, the system looked and functioned much differently than previous designs. The CPI system utilizes one main injector that pressurizes six plastic tubes housed in the intake manifold. Each tube terminates in a spring-loaded poppet valve that supplies fuel to its corresponding cylinder.
What is the pressure of the fuel injector?
The main injector is pulsed twice per crankshaft revolution, with pressurized fuel opening each poppet as system pressure approaches approximately 48 psi. The main injector and fuel pressure regulator on the CPI system are housed in a molded plastic piece with the six plastic tubes attached.
What are the symptoms of a bad fuel injector assembly?
Symptoms Of A Bad ‘Spider’ Fuel Injector Assembly. The most common type of failure (related to the ‘Spider’ fuel injector) is usually not the assembly itself going bad, but the fuel pressure regulator going bad. The fuel pressure regulator is infamous for leaking fuel from its vacuum inlet nipple.
When to replace the CSFI fuel injector assembly?
The CSFI does use a MAF sensor and the plenum is plastic and was used from 1996 on up on the 4.3L, 5.0L and 5.7L engines. Also, when anything fails in the CPI type system, you have to replace the entire fuel injector assembly. In the CSFI system, all parts can be replaced individually.
How does the CPI fuel injection system work?
Though the CPI system supplies fuel to each of the engine’s intake ports like other multi-port fuel injection systems, it has only one centrally located fuel injector, called the MAXI injector. Some bean counter at GM probably came up with the idea as a way to reduce costs.
The main injector is pulsed twice per crankshaft revolution, with pressurized fuel opening each poppet as system pressure approaches approximately 48 psi. The main injector and fuel pressure regulator on the CPI system are housed in a molded plastic piece with the six plastic tubes attached.
What kind of injector do I need to test CPI?
An off-the-vehicle injector tester is by far the best choice for testing fuel flow on a CPI engine. If one is not available, there’s an alternative test that can be performed after the plenum is removed. Begin the test by removing the coil wire from the distributor and securely ground it to prevent the engine from starting.
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.
