Change your fuel filter

**jad628** · 08-07-2007, 03:47 AM

Well, I've had my Z28 for about a year and a half. I've put about 14,000 miles on it for a total of 80,000. I crawled under it the other day and took a look at the fuel filter. I suspected it was the original one. I'd recently experienced a slight miss at very low rpm's (it's an M6) when traffic would slow down on the Interstate and speeds dropped to below fifty. Sometimes I would stay in sixth (around 1000 rpm) and just accelerate slowly. This is when I noticed the miss.

Well, I changed the fuel filter and the miss went away. I decided to open it up and see what it looked like. I figured those of you with a lot of miles on your fuel filter might want to see what one looks like.

Needless to say I highly encourage you to take the ten minutes it takes to change your fuel filter on a regular basis. I figure I'll change it about every fifth oil change from now on.

**JOHN_DEERE_LS6** · 08-07-2007, 04:20 AM

i got abotu 75000 on my m6 t/a and when im slowly shifting through the gears i noticed a slight lull between 1500-2200 in 3rd and 4th rpms id say i wouldnt call it a miss jsut like alil delay in ooo i dunno the pulling feeling of a motor building rpms.... get what im sayin or no?!?!? think this might be result of my fuel filter as well??? your pic has me wondering,,,,,,

**jad628** · 08-07-2007, 04:43 AM

Originally Posted by John_Deere_LS1

i got abotu 75000 on my m6 t/a and when im slowly shifting through the gears i noticed a slight lull between 1500-2200 in 3rd and 4th rpms id say i wouldnt call it a miss jsut like alil delay in ooo i dunno the pulling feeling of a motor building rpms.... get what im sayin or no?!?!? think this might be result of my fuel filter as well??? your pic has me wondering,,,,,,

Yeah, I understand what you are saying. My experience was with very low rpm's (say 1000-1500) but when the rpm's built up, it didn't happen. I had a fuel filter handy so I figured I'd start with that. I also took the throttle body off and cleaned it, plus blew out my K&N with some low pressure air (it has the free cold air mod so it tends to pick up more debris). I also used a grinder to remove a little metal from the linkage stop to allow the blade to open close to a full 90°. I did all that at the same time and the "miss" went away. My money is on the filter being the culprit. It smelled terribly strong of "old gas" and I think the filter material was saturated with impurities that restricted the flow of fuel at the lowest rpm's, but not so much when accelerating at normal rpm's.

The guy who had the car before me left it stock except for exhaust. He seemed to maintain it okay, but a lot of people seem to avoid the fuel filter as regular maintenance. My Dodge truck requires the gas tank to be pulled (the filter is on the in-tank pump) so that's a pain, but the fuel filters on these cars are simple to replace.

**Spaz** · 08-07-2007, 04:49 AM

i change my fuel filter every 3rd oil change i do...

**9t8z28** · 08-07-2007, 04:59 AM

Wow!

**ggino85** · 08-07-2007, 06:27 AM

so were is ur fuel filter, ive looked under the car but dont really know where or what to look for. also when you change it is there a high performance filter or are they all the same

**jad628** · 08-07-2007, 06:51 AM

Originally Posted by ggino85

so were is ur fuel filter, ive looked under the car but dont really know where or what to look for. also when you change it is there a high performance filter or are they all the same

It's underneath, on the driver's side. Look undeneath about where the door handle is. It's cylindrical, maybe 4-5 inches long, and held in place by a friction band/clamp that you do not have to remove. All it takes is a jack for the rear left wheel, and two wrenches (adjustables will work). You'll lose a bit of gas, but not much if you're prepared. Remember to release the pressure in the fuel rail before you start.

I don't know what different types of filters are out there. I think Advance Auto only had Purolator.

**The Scientist** · 08-07-2007, 06:53 AM

Fuel filters can definately lead to 1) poor efficiency 2) straining your fuel pump until it goes and 3) engine studder, spurtering, dieing out, and even to the point while cruising down the highway the motor shuts off for a few revolutions. I always change my filter every 15k or once a year.
But just two weeks ago I was reminded why I always do that. I was taking a road trip and after about 70 miles the motor started to die out then would run fine for a mile then do it again a couple times. It would even die out completely at red lights. Scared the hell out of me!!! I immediately thought either MAF or fuel pump. Needless to say I ended up picking up a new filter at a Wal-mart and changed it in the parking lot. (Talk about a bitch to do in the dark with no lift.) Problem solved...not to say that my fuel pump may be going bad as well but changing the filter solved the immediate problem. The old filter was so clogged that the fuel remaining in the filter would only drain out the back and I could hardly blow air through it anymore! I am sure it looked worse than the pics or yours.

Morale: Always, and regularly, change your fuel filter!

**ggino85** · 08-07-2007, 06:56 AM

how do you release the pressure on the fuel rail.and is this somethng a rookie should be messing with?

**Tman** · 08-07-2007, 07:02 AM

Originally Posted by ggino85

how do you release the pressure on the fuel rail.and is this somethng a rookie should be messing with?

Go to www.installuniversity.com

There is an excellent write up

**jad628** · 08-07-2007, 07:05 AM

Originally Posted by ggino85

how do you release the pressure on the fuel rail.and is this somethng a rookie should be messing with?

Look under the hood at the fuel rail above the intake. Near the front of it (driver's side I think) there is a cap on it. Remove the cap and you will see a valve similar to a valve stem on a tire. Just push in on it and it will remove a small amount of fuel (not much at all). That's all you need to do.

Sorry, I forgot to mention the gas cap. You should always remove it when changing fuel filters.

**INMY01TA** · 08-07-2007, 07:24 AM

Did mine last year.

**ggino85** · 08-07-2007, 07:25 AM

thanks, that is an excellent write up, do you guys think i really need to take the fuse for the fuel pump out or could i just skip that?

**Hot Black Trans-Am** · 08-07-2007, 07:49 AM

I was told to pull the fuel pump fuse while the car was running to relive the pressure. I change mine every spring. Before I changed it the first time I would get pinging sound at high rpms and after it went away.

**Starion** · 08-07-2007, 10:45 AM

As long as your key isn't in the ignition the fuel pump isn't going to run. I just removed the gas cap to relieve pressure and changed it. A little bit of gas trickled out which I let drain into a small pan. It's by far the easiest fuel filter I've ever changed in a car. Took 10 minutes max.

**JonB** · 08-07-2007, 01:17 PM

I need to change mine its been awhile.

**1TA LS1** · 08-07-2007, 01:28 PM

Nice pictures and great write up..... I change mine every year, regardless of the miles.

**Dillard99** · 08-09-2007, 06:48 PM

hey thanks Jad and every one for this good info thats one thing
I forget to do i change mine a lil over a year ago doing mine this week

**LS1formulafreak** · 08-09-2007, 10:09 PM

just changed mine, im pretty sure it was the stock one, if not it still had at least 40k on it, wish i saved it so i could open that sucka up. i wasnt havin any probs though so maybe it wouldnt have been too bad

**jad628** · 08-10-2007, 03:13 AM

Originally Posted by Dillard99

hey thanks Jad and every one for this good info thats one thing
I forget to do i change mine a lil over a year ago doing mine this week

You're very welcome. I caught a little grief at work because folks thought it was strange that I would take the time to photograph it. One guy said the new one probably already looks the same. Well, I agree that it doesn't take long for filters to "look" dirty, but the smell of the old filter is one I can't explain in words except stale gas (some know what I mean), and the fact it would only dribble out fuel tells me there is a big difference between the old and the new.

Of course, us LSx folks appreciate our cars as something more than just a disposable piece of transportation. There's no use trying to explain that to the masses.