Why Fuel Injectors Get Clogged & Fail to Perform Properly?
Extreme heat will cause olefins and varnishes to accumulate on the injector pintle and seat. This is especially the case when the vehicle is driven on short trips and the engine "heat soaks". EGR (Exhaust Gas Recirculation) and PCV (Positive Crank Case Ventilation) systems return gases and contaminants through the intake system as well as exposing the injector to excessive heat created from this process. Multi-port fuel injectors are located behind the engine intake valves where leaking valve seals cause oil residue to accumulate and cook onto the injectors. Injector failure rates are higher on turbocharged engines because of higher heat developed by the system.
Why is Injector Reconditioning Required?
Many vehicles on the road have clogged and malfunctioning injectors, which directly results in:
Poor fuel economy, hard starting problems, rough idles, stalling, lack of proper performance/acceleration, and excessive emissions causing vehicle to fail enhanced emissions testing.
Getting your injectors maintenanced or replaced outweighs the benefits of the latter.
Crankshaft Grinding: The main parts we are working with when grinding are the main & rod journals. In the midst of the engine rebuild it will be determined if the journal surfaces are within sufficient tolerances to be reused as is or if they will need to be ground. If the crankshaft can be reused but machining will be necessary in order for it to work, the crank's top layer will be ground to make it smooth again. Depending on the severity of the wear, the amount taken off is usually measured by 0.010", 0.020", or 0.030" and so on.
Here are some of the many reasons why they may need to be machined:
- Surface of the journal has wear which makes it no longer smooth.
- If the journal is out of round.
- If the journal is not square (same diameter at both ends of the pin).
- Can also be ground to produce more stroke.
Crankshaft Polishing: The process of polishing finishes the journals after being ground to the final measurements. This involves using using a long circular piece of emery paper. Polishing creates an extremely smooth surface which reduces friction and improves overall power and torque.
Crankshaft Bearings: Excess space which is taken away during the grinding process needs to be filled by using under-sized bearings. The bearings are matched to maintain the proper clearances for oil flow at the new diameter of the journal.
