Tip & How-To about Chevrolet 1500

Fuel filters and how it affects drivability.

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 on

Cars & Trucks Logo

Related Topics:

Related Questions:

1 Answer

1996 nissan quest will not turn over it wants to start but wont does this mean the timing belt is broke?


Hello. Not necessarily. There are many possible causes of it not starting. Begin by changing the fuel filter. If that doesn't help, change the air filter. Finally try some starter fluid sprayed into the air intake when the cover is off of the air filter.

Sep 25, 2010 | 1996 Nissan Quest

1 Answer

lpg conversion on Audi a8. 3.0l The cat has been wrecked, £2500 to replace, likely causes? The garage changed injectors 6 weeks in to reduce fuel, could that have been problem?


Yes it sure sounds like it could be.....the cat probably heated up way to much due to a bad fuel mixture

Changing injectors is never a way to go to reduce fuel flow. the injector will only spray as much fuel as the computer tells it too. The controls for the LP were probably not installed properly or not adjusted correctly.

And you may have had a marginally bad convertor to begin with before the conversion, and a bad conversion made it worse.

Feb 02, 2010 | 2005 Audi A8

2 Answers

Ran out of gas, Got car started for a few minutes with a gallon then conked out and won't re-start. Put some dry gas in tank in case gas can w/old gas. Maybe fuse or fuel pump? Don't know where pump is & how to test/replace!


Could be a dirty fuel filter, or intermittent fuel pump. To test the fuel pump, put the key in the ignition, then turn it up one, not start but on, and listen near the gas tank area for a click or some type of noise. If none then it might be the fuel filter (note if you don't hear anything it doesn't necessarily mean that the pump is bad). Now as for the fuel pump, it's located under the car near the gas tank and you can easily un-clip it (be careful as it might be full of gas) and that's how to remove it. Hope this helps. Best Regards.

Nov 11, 2009 | 1995 Buick Riviera

1 Answer

98 mazda b2300 truck wont start.fuel problem.


i would try replaceing the fuel filter frist.then i would un hook the fuel line and see if you got gas to the fuel filterthat will tell you if your fuel pumpis working or not . ok good luck

Apr 19, 2009 | 1998 Mazda Pickup

Not finding what you are looking for?

465 people viewed this tip

Ask a Question

Usually answered in minutes!

Top Chevrolet Experts

yadayada
yadayada

Level 3 Expert

75235 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22095 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

7795 Answers

Are you a Chevrolet Expert? Answer questions, earn points and help others

Answer questions

Loading...