Can't find external fuel filter

[Barronjr]

Hello.
Sorry if im posting this in the wrong place.
Im pretty lame when it comes to na igating forums.
We recently bought a 2005 four winds 5000 23a class c on a chevy chassis.
It has very low 37k miles.
I think it was a bad idea to purchase because it had been sitting since 2012.hence the low miles.
The gas gauge was on E so
I put 5 gallons of gas in it to drive it home 15 miles.
Check engine light came on flashing .misfire i presume.
I pulled the code.it was the dreaded p0300.
Random misfire code.
I changed all spark plugs and wires with ac delco parts.oil change as well.
I added another 8 gallons of gasoline.
Still the same.
My next move was to change the fuel filter.and see if it was getting plugged up.
I havent changed the coil packs because of the low mileage.
All though the tank was near empty.who knows what kind of crap is in there and what might have gotten into the fuel filter.
Knowing its a chevy chassis.i bought a wix fuel filter and got u derneath to check the frame rail for the ff.
Boy was i depressed when i couldnt find a external fuel filter..
Where is it?
Im sadly thinking its in the fuel tank.
Please advise.
What would you do?
Change the coil packs first or drop the tank?
Check it out.install new fuel pump?
Would it be a chevy express 3500 fuel pump?
Or something different.
Please help me folks.
Thank you for reading this long post.
Is it in the darn, huge fuel tank?
Ive been working so hard to get this rig up and ready.
Now i feel really depressed about my purchase decision.

[Mudfrog]

I would check fuel pressure at the injection rail. I'm sure there is a test shrader valve there. Fuel pressure test kits are cheap on Amazon. Hook it up and you'll know pretty quickly whether there's enough fuel making it to the engine.

As far as the filter, would think it was inside the chassis frame somewhere along the driver's side.

[Barronjr]

Thanks Mudfrog.
Your right.
I should test fuel pressure.
I will rev it while testing as well.
I have a nice fuel pressure kit i bought 2 years ago.
I got tired of renting it from yhe auto parts store.
It might be a late 05 or early 06 production.
Ive been reading chevy went to a filter/fuel pump module set up late 05.
Thank for commenting.

[Skip426]

Workhorse chassis guide is too large to post in the forums , I separated this page .

[RickNC]

Fuel filter is usually on the passenger side frame rail.
Before you start slinging money and parts at it carefully go through the vacuum hoses looking for leaks. Check all the engine wiring for signs of damage by rodents especially around the coil packs and sensors. Both of those issues will set a misfire code

[Bonzen]

Also, random misfires can be caused by clogged/leaky injectors. Since its been sitting for so long with bad gas they could be gummed up. If you cant rule out the other simple things to check, you may need to get the injectors ultrasonically cleaned. Its usually a few hundred bux.


The other "bad" thing that could happen, and Ive seen this - the valve stem seals are dry rotted from not being oiled in the heads from sitting so long, and now oil is seeping by them into the combustion chamber and screwing with the air/fuel mix. Hopefully its not that. But that will cause random multiple misfires.

[Barronjr]

Thank you Skip.
I didnt check the passenger side that far back.
So tomorrow i will.
The info helps but didn't specifically mention a 2005 and newer 6.0 litre configuration.
Im hoping its there on the passenger side near the rear axle.
But i didnt see any fuel lines on the passenger side frame rail midships.
Thanks again.

[Barronjr]

Thank you Rick.
Good advice and i hope it on the passenger side.
The fuel lines were on the drivers side inner frame rail.

[Barronjr]

Thank you Bonzen.
Ill do a fuel pressure test tomorrow.
Yes injectors are a worry.
Valve stim seals are probably ok..since i changed the plugs.none of the old ones looked bad or oily.

[Mudfrog]

Originally Posted by RickNC

Fuel filter is usually on the passenger side frame rail.
Before you start slinging money and parts at it carefully go through the vacuum hoses looking for leaks. Check all the engine wiring for signs of damage by rodents especially around the coil packs and sensors. Both of those issues will set a misfire code

Your post got me to thinking. I thought for sure the filter on my P32 was on the driver's side. Wanted to make sure so crawled under there just now and see that you are right, it's on the passenger side. On mine, inside the frame rail, front of the rear tires, right next to the muffler.

Of course it's not a P32 chassis we're talking about here.

[THenne1713]

Tank in E, I wud suspect water in fuel? Had recent event w/ vintage pickup, filled up an hour after gas tanker dump and ended w/ bad miss for about 3-miles. Next day and weeks after was all clear. Cross fingers, add gas and HEET and Good Luck.

[Barronjr]

Update .
I took her to a shop.
1 bad injector and 1 bad coil.
Changed all 8 injectors .installed 1 new coil.
Runs great now.
Im still worried about the fuel tank and lack of external fuel filter....
I guess in late 2005 some chevy trucks had no external fuel filter.
Just a,strainer in the tank.
Bummer.
Thanks to all of you who followed and the great folks who took the time to comment.
Thank you!

[Arch Hoagland]

Thanks for the update...glad to hear all is well.

[Bonzen]

Originally Posted by Barronjr

Update .
I took her to a shop.
1 bad injector and 1 bad coil.
Changed all 8 injectors .installed 1 new coil.
Runs great now.
Im still worried about the fuel tank and lack of external fuel filter....
I guess in late 2005 some chevy trucks had no external fuel filter.
Just a,strainer in the tank.
Bummer.
Thanks to all of you who followed and the great folks who took the time to comment.
Thank you!

Good news, hopefully the 8 new injectors weren't an arm and a leg lol.


Go buy yourself a "cheaper" aftermarket brand coil pack to keep as a spare in the rig. Once one goes bad, the others are on the same borrowed time theoretically.



The fuel injectors that your rig uses are probably large enough to pass through any stuff that makes it through the in tank strainer bag. That, or the injectors have screens inside them that filter out the small 10~ish micron stuff. But that will eventually clog up too.