Loss of Power Under Load Solved

First time posting here, figured I would share a success story:

2004 Tundra Double Cab, 4x4, 230K miles.

My truck started to get a little hesitant under load and progressed to where if I nailed the throttle anywhere it would fall on its face. No rough idle, no hard starts. My prime suspects were:
1) Fuel Pump failing (unlikely, seems to be a go/no-go type deal)
2) Fuel pump circuit issue (unlikely, a failing fuel pump resistor tends to cause hard starts/bad idle)
3) Fuel pressure regulator issue
4) Fuel filter (most of the internet says to resist the urge to change this as its not the problem, doggonit)
5) Plugged cats?

I hooked up fuel pressure gauge and noted a very nice 42psi at idle and at partial throttle openings. When I nailed the throttle it rolled off to a leisurely 8psi. Ok, its not the cats. I then shorted the fuel pump resistor to force the pump into high flow all the time and went for a drive. Fuel pressure still fell off hard when the skinny pedal got stabbed.

Screw it, I'm replacing the fuel filter. I believe my '04 is the last year with an inline fuel filter... after that its just the mesh/bag filter on the fuel pump inlet in the tank I believe...
I replaced the fuel filter and the truck runs perfectly under heavy load, problem solved.

I cut open the fuel filter and pulled out the element which looks like a roll of party streamer stuffed into the can. No big dirty slug of mud or anything, but a fairly consistent white, plastic-y gunk that would crumble off the paper. Below is a photo of the unrolled paper, interesting. Any ideas what it is? I blame ethanol.

 

+1 for blaming ethanol. Ethanol is garbage.

 

@shifty` it finally happened.

 

never say never ig

 

If the 04’ looks like that, I wonder what the sock looks like in my tank.

My understanding, 05+ no inline filter (plastic tank and VVTI)

 

The proximity to my statement made days ago about “… after 4 years of it literally never being a fuel filter for anyone, watch a newbie pop out of the woodwork in the next couple of days with their 1st post saying it was totally the fuel filter causing their issue” almost makes this highly suspicious.

What you’re seeing in that filter is what I’ve found in filters on GenIII SBC swaps we’ve done using aluminum fuel cells. Basically aluminum oxide, may as well call it precipitate. Zinc from galvanized steel will do the same. Neither of those metals should be existing in a 1GT tank, though, so it’s curious to say the least.

I’d need to cut open an OEM filter to see if that’s typically what they look like inside, understand whether there’s something else going on here. @OP can you post up some pics of the open fuel filter so we can compare its can to OEM? Does the canister have a clearly visible part number on it anywhere? Could be helpful to better understand what’s at play, whether anyone else needs to be concerned, or maybe this is cheap aftermarket; I wouldn’t expect OEM to use that specific material for filtration, it looks too susceptible to loading up.

 

Is the dirt on his hands make-up?

 

Here you go. “White rust”. I couldn’t remember what the nickname for it was: https://www.thehulltruth.com/2101608-post22.html

That post touches on it a bit. But here’s the thing, two things actually. First, normally that precipitate should fall to the bottom of the tank where it sits comfortably, just hanging out (although in our 1GT tanks there shouldn’t be anything to create that precipitate; unless someone is running around pissing in your tank or dropping zinc tablets in it). Second, if it ever were to get sloshed up off the bottom of the tank - unless someone changed the OEM fuel pump at some point, or the sock from the fuel pump fell off its pickup somehow, it should never make it into the main line to reach the filter.

Not saying it can’t happen, didn’t happen, or wont happen, only it shouldn’t ever happen.

 

What are the 00’-04’ tanks coated with then if they are not galvanized

 

Just saying, it would take a hell of a lot of zinc to produce that much precipitate. And you’d be seeing this daily on every automotive forum if galvanized steel tank was the culprit here.

 

I thought '04-'06 had plastic fuel tanks.

someone at TS opened a metal tank, if i can find the pic, i'll post it, because i think it had a pale colored paint inside.

might've been @BroHon

 

No, 05-06 is like Gen 1.25

 

@Diablo169 is right. 05-06 is plastic. 00-04 are galvanized per Dorman, as are many other makes/models of that era. I think 00-02 may use a part separate of 03-04. 00-04 have ovular opening, 05-06 round.

 

Theres been whole lot of Galv tanks over the last 50 years. I don't see this being an issue with standard fuel blends.

 

Ah man, you caught me...ha! But seriously... every hard start/rough idle problem seems to definitely not be the filter. Anyway... not sure if my filter was OEM or not. I've had the truck for 11 years and 100k miles. I went out and found I hadn't thrown away the canister yet, here it is:



Had a plastic stem in the middle of it:

 

Ah crap, forgot to re-apply when I put the new picture up...

 

Yeah, that's not OEM. Motorad, Purolator, and Delco all sell Israeli-made parts, wouldn't doubt if it was one or the other. I wouldn't be surprised to learn OEM actually uses metal mesh inside, but ... I'd need to source one from a JY and slice it open.

If anything, this is a screaming testament to how high-quality Toyota's filters are. You've got some guys on here running their original Toyota fuel filters, 100k, 200k, 300k miles in with no issues.

Makes me wonder ... why'd the original owner abandon the OEM filter? "Routine maintenance"? Also drills home a good point. I should be prefacing or suffixing my fuel filter commentary with "... if OEM ..."

 

I may end up at the yard this week. If so I'll grab one for science.

 

Interesting... I just put an OEM one back on, but I ain't gonna back it off for science! I looked around for different fuel filter cut-open pictures and it seems like my Purolator, or whatever it is, wasn't very different internally. Now, the OEM does seem to have a corrugated collar of paper I'm guessing on the inlet side which probably allows it to take on more crud before fully plugging. Check out this Taco filter operning: https://www.tacomaworld.com/threads...ur-fuel-filter-03-3-4-more-pics-added.476590/

 

Grab a red access cab exterior door handle for @bmf4069 while you're there

 

Why? It still works. You just have to open it with one finger....

 

Just need a loop of rope.....

 

FTFY

 

I would never run a non OEM fuel filter. You don’t know what Toyota knows.

That filter could have been filtering too much or too little. .03 microns are the sneaky ones.

I think it was on the 6.4L SuperDuty’s. Ford knew the tanks released a certain amount of a type of particle, so they had a special layer in their filters to catch it. None of the aftermarket companies had that extra layer, and Ford wouldn’t warranty the damaged due to using aftermarket filters.