When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
How to tell the difference between air in lines & bad injector
So is the sound the same when you have air in fuel as when an injector is bad? Is there a specific injector that will clack when air is in there? Or do they all do?
Let's rule out #8 for the sake of simplicity.
When air is in the fuel, #2 and #7 get first dibs on the frothy soup. I say "frothy" because while many people have a hard time believing air bubbles make it to the bottom of the fuel bowl (fuel exit to the heads) - I don't think anybody would have a hard time believing running fuel in an open blender will make froth. Take air in fuel in a vacuum or no pressure (fuel inlet to pump) and pass it through a spinning pump - you get pressurized froth. The froth can't separate into bubbles quickly enough before it reaches the fuel lines, so #2 and #7 get a piece of this.
I have damaged three pairs of injectors because of air in fuel - 3 sets of #2 and #7. Some of the symptoms can include louder knocking on an uphill grade (higher ICP hammers the froth harder), bucking under the right fueling conditions, and an increasing knock over time. I now have my last injector to swap out, and I allowed the problem to progress further than before. I fixed the air problem, but the damage is done and growing. I now have a fueling imbalance on #2 stick, and the truck feels like it has a slight miss. My dual EGTs and the IR gun have confirmed the bad stick.
You can illuminate a suspect injectors solenoid using a Scope. Then, you know if you need to dig deeper into the injectors spool valves and/or identify the air.
* Ensure your scope / attenuator is capable of 150vdc or greater.
You can illuminate a suspect injectors solenoid using a Scope. Then, you know if you need to dig deeper into the injectors spool valves and/or identify the air. * Ensure your scope / attenuator is capable of 150vdc or greater.
NIICE. Always wanted an excuse to buy a scope!
Will a 200 $ usb pos be enough?
