Showing posts from March 21, 2010

external electrical connectors broke/corroded

CAUSE OF FAILURE 6...mishandling during installation/removal/testing, water/moisture leaking past injector plug connector, inadequate vehicle maintenance, improper storage.EFFECTS OF FAILURE firing, intermittant firing, or weak firing of injector due to poor electrical conductivity , poor engine performance, poor fuel economy. engine overheating, potential engine damage, overfueling of other cylinders as 02 sensor reads excess 02 in exhaust and adjusts "rich" to compensate.

injector pintle doesn't fully seat on orifice

CAUSE OF FAILURE 5...fuel additives "baked" on pintle or orifice, weak injector return spring, rust/corrosion internal to injector body.EFFECT OF FAILURE 5...leaking fuel injector, after shutdown fuel leak in affected cylinder (causing hard start), overfueling of affected cylinder with resultant underfueling of remaining cylinders in the "closed loop" system, potential for damage to O2 sensor or "cats".

Body or mechanical joint leak in injector body

CAUSE OF FAILURE 4...Defective manufacturing and testing, overheating of injector from cooling system failure, ignition system failure, incorrect timing, improper "handling" during installation/removal/storage/shipping, etc.EFFECT OF FAILURE 4...High potential for engine fuel fire (dependent on location of leak), poor engine performance, poor fuel economy, potential for engine damage.

Injector windings don't lift pintle, seized pintle, or slow pintle cycling

CAUSE OF FAILURE 3...injector coil windings overheated from cooling system failure or ignition failure, with windings losing their magnetic performance; open (broken) windings; shorted (grounded) windings; seized pintle from internal injector corrosion (engine has set too long without running causing the injector to rust internally, petrol contamination with water, or cycling of injector without fuel flow to act as cooling agent and lubricant). EFFECTS OF FAILURE 3...(A) If injector pintle is "off" the seat...overfueling of affected cylinder with resultant underfueling of remaining cylinders within "closed loop", poor engine performance, poor fuel economy, possible O2 sensor damage, potential engine overheating and engine damage, hard or no start, fuel leaks after shutdown. (B)If injector pintle is "on" the seat...underfueling/no fueling of affected cylinder with resultant overfueling of remaining cylinders with "closed loop" system, poor eng…

Injector filters become clogged

CAUSE OF FAILURE 2..."Foreign particles" in fuel tank(s) or fuel lines, or fuel rail. Foreign particles in almost all instances, will be rust. Larger rust particles may be collected within the injector filter, or the fuel filter, and reduce fuel flow. Microscopic rust particles may also pass thru the injector filter, and cause the spray pattern to alter, fuel flow to alter, and/or the injector pintle to not seat properly. This is a common problem on vehicles that have sat unattended, or suffered from lack of routine maintenance. Incorrect fuel tank fuel filter; holes/tears in fuel tank fuel filter; breakdown/degradation of interior wall of fuel supply line; breakdown/degradation of interior wall of fuel injector hose, and rust in the fuel rail.EFFECTS OF FAILURE 2...the injectors leak at the pintle and/or the spray pattern is altered, and/or the fuel flow is altered. Lack of engine power from underfueling; potential for engine overheating; remaining injectors/cylinder…

Fuel Injectors Work

The TBI system took the place of the carburetor as governmental automobile pollution standards increased , as well as a simultaneous increase in consumer requirements for greater fuel economy. In the TBI system, a throttle body sits atop the engine in the location where the carburetor use to reside. The throttle body in fact looks very much like a carburetor, however it performs very much differently. Located within the throttle body are one or two injectors (depending on the vehicle). When the engine is started, a continuous spray of pressurized fuel is discharged thru the injectors, into the intake manifold, and from there on to the cylinders for combustion. The injectors in the TBI system are always open, and spraying fuel when the engine is on. They do not pulse on and off. Furthermore, the one or two injectors are supplying fuel to every cylinder collectively, as did the carburetor, but with much greater precision. While the TBI system, and the advances in engine manage…