Fuel Filter/ Fuel question

[CarlaValentine]

I noticed today after driving around for a while that despite a new catalytic converter installed yesterday and a new coil to cure a misfire, something still didn't feel quite right to me about the way my car was running. It seemed to be "breathy" for lack of a better word, as if it was getting too much air and/or not enough fuel. For some reason the fuel filter stuck out to me, probably because it hasn't been changed since I got the car...and who knows when before that. I figured, it's a 10$ part, what's to lose? When changing it I noticed that there was fuel pressure on both ends of the filter as it was being disconnected (NO I didn't bleed the fuel pressure off at the shrader valve first. Yes I know that's a bad idea.) The old one was pretty bad. Trying to blow through it was like trying to blow a golf ball through a straw, and a lot of black gunk came out of it. With the new one in the car runs a lot better. The breathy sound went away completely. Also, my idle fluctuation has completely stopped.

I have 2 questions. 1- could the clogged fuel filter have caused an idle issue? Or is that purely coincidence?

2- given the amount of black crud that came out of the old filter, would it be a safe/good idea to put some fuel injector cleaner in the gas tank at my next fill up to eliminate any leftover gunk that may have made its way down the lines?

[Cadillac Jim]

A clogged fuel filter will give the car the water-in-the-gas syndrome of fuel starvation. I'm not very familiar with it in digital fuel injection cars but in carburetor cars it has effects that vary from "running out of breath" as RPMs increase to frequent stalling.

You'll get a lot of advice to avoid gasoline additives because of possible effects on the fuel pump and such. The one that's guaranteed safe and will absorb water out of the gas is Techron, available from Chevron, or possibly as a GM part number. You might find these Wikipedia articles interesting:

On Techron:

http://en.wikipedia.org/wiki/Techron

On "Top Tier Gasoline:"

http://en.wikipedia....ergent_Gasoline

The thumbnail of all this is that you can get the benefit of water absorption, injector cleaning, etc. of the best gasoline by adding a can of Techron to your gas tank. Note that the article on top tier gasolines that the list of gasoline brands and grades that meet these standards does not include some very good gasolines, apparently because the refiner of that particular brand or grade has not applied for testing and inclusion in the list. Arco and BP premium grades are mentioned in the article. IMHO, you can fill up with the premium grade of any leading brand and have top tier gasoline. So, if your car is running OK and you just want to clean it out, you can save yourself some trouble by running it down below a quarter tank and filling up with a good brand of premium gasoline. But, if you still notice any driveability problems, you can go buy a can of Techron and put in in the tank with the gas you use now. If you already normally run premium gasoline from any leading brand like Exxon, Gulf, Shell, BP, Arco, Chevron, Texaco, Lukoil, etc. then all you need to do is to take the car for a nice ride in the country soon.

[Ranger]

could the clogged fuel filter have caused an idle issue? Or is that purely coincidence?

It's a coincidence. If the filter was clogged enough to affect the idle, you'd have a very hard time getting the engine to run at anything above idle. It would be undriveable.

[adallak]

I noticed today after driving around for a while that despite a new catalytic converter installed yesterday and a new coil to cure a misfire, something still didn't feel quite right to me about the way my car was running. It seemed to be "breathy" for lack of a better word, as if it was getting too much air and/or not enough fuel. For some reason the fuel filter stuck out to me, probably because it hasn't been changed since I got the car...and who knows when before that. I figured, it's a 10$ part, what's to lose? When changing it I noticed that there was fuel pressure on both ends of the filter as it was being disconnected (NO I didn't bleed the fuel pressure off at the shrader valve first. Yes I know that's a bad idea.) The old one was pretty bad. Trying to blow through it was like trying to blow a golf ball through a straw, and a lot of black gunk came out of it. With the new one in the car runs a lot better. The breathy sound went away completely. Also, my idle fluctuation has completely stopped.

I have 2 questions. 1- could the clogged fuel filter have caused an idle issue? Or is that purely coincidence?

2- given the amount of black crud that came out of the old filter, would it be a safe/good idea to put some fuel injector cleaner in the gas tank at my next fill up to eliminate any leftover gunk that may have made its way down the lines?

Have you tried to blow through a new filter? Fuel pump puts some 40 psi through it, I doubt you can do the same.

[CarlaValentine]

I noticed today after driving around for a while that despite a new catalytic converter installed yesterday and a new coil to cure a misfire, something still didn't feel quite right to me about the way my car was running. It seemed to be "breathy" for lack of a better word, as if it was getting too much air and/or not enough fuel. For some reason the fuel filter stuck out to me, probably because it hasn't been changed since I got the car...and who knows when before that. I figured, it's a 10$ part, what's to lose? When changing it I noticed that there was fuel pressure on both ends of the filter as it was being disconnected (NO I didn't bleed the fuel pressure off at the shrader valve first. Yes I know that's a bad idea.) The old one was pretty bad. Trying to blow through it was like trying to blow a golf ball through a straw, and a lot of black gunk came out of it. With the new one in the car runs a lot better. The breathy sound went away completely. Also, my idle fluctuation has completely stopped.

I have 2 questions. 1- could the clogged fuel filter have caused an idle issue? Or is that purely coincidence?

2- given the amount of black crud that came out of the old filter, would it be a safe/good idea to put some fuel injector cleaner in the gas tank at my next fill up to eliminate any leftover gunk that may have made its way down the lines?

Have you tried to blow through a new filter? Fuel pump puts some 40 psi through it, I doubt you can do the same.

I actually did blow through the new one just to make a comparison. Lol. It was still hard, yes, but nowhere near as bad as the old one. At least I could get air through the new one.