Tip & How-To about Chevrolet 1500
I wonder how many fuel filters have been replaced un-necessarily. In the millions would be a beginning.
But conversely there are many that should have been changed but not done either.
OK, here is a little history first.
In carburated engines of the past in most vehicles the fuel would only pass through the filter once. The tiny filters in the carb would last a long time under normal circumstance.
Then along came fuel injection systems.
The fuel pumps in the tank supply fuel pressure up through a line to a fuel filter. From there it would lead to the injector fuel rail. On the rail a fuel pressure regulator would adjust pressure to the specification of the system. Then out of the regulator back into the fuel tank.
So you can see that this system is continually running the fuel in a loop. This means the filter is continually filtering fuel. They made the filters larger for these systems to allow for that.
These systems are now being phased out.
Models made in the last few years have gone to a returnless system where the fuel is delivered to the fuel injectors by only a supply line and no return line.
Many of these systems do not have a fuel filter that is serviceable outside the fuel tank.
Filters are mounted inside the fuel tank before the fuel pump. But check your model of car to verify that it does or doesn't.
The fuel moving around inside the tank is keeping these filters from plugging up I suspect because I have not seen one of these setups plug off in my shop to this point.
Moving on now, as far as symptoms are concerned.
A fuel filter will rarely cause a no start problem. Unless there was water in it and froze. Or it was plugged off to the point it overworked the fuel pump, burned it out and won't start the pump again.
Ok so how do you know the symptoms of a fuel filter issue?
Well what you would notice at first is when you are accelerating it seems to die out or lose power slowly and actually pick up speed when you let off the fuel. The reason for this is not enough fuel can pass through the filter to keep up with the engine fuel requirement under acceleration and when you back off the throttle it brings the demand back into the window of supply to make your engine run properly again.
Now I must make a note here that there are a couple other items that will give similar symptoms. Air supply and exhaust restrictions will also feel similar.
So the reason I am writing this for you.
Don't change a fuel filter for an engine misfire or just because you don't know what else to do. Do some research first, some filters are a hassle to change anyway.
Don't get me wrong here. The filter if you have one is still a maintainence item. But get the guy who does your oil changes to do it for you. It's a lot easier to do on a hoist than crawling under and getting fuel sprayed in your face.
Posted by FUBAR on
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