Pulled the engine recently to have it rebuilt. We were very meticulous when it came to disassembly. The filter is asymmetric so you can't mix it up. When we took the fuel filter off it looked like this:



We marked it "front" and "rear" The rear is the outlet side (goes directly to fuel rail) and the front is the inlet side. The new one I got at napa has a big arrow on it pointing towards the front of the vehicle. We installed the filter in the same orientation as the way we pulled it off but if you read the arrow to mean "flow direction" it is opposite or what it should be. No directions on the box. Is Napa stupid and printed an arrow that meant "front" instead of "flow". The filter we removed has a Toyota stamp on it so I assume the PO didn't mix it up at some point. Can anyone confirm orientation or Napa stupidity?

 

same thing here...but mine wasnt an original fuel filter. i installed it the other way (fallowing the flow arrow )and it seems to fit better...

so which way is correct?!?! i didint notice any difference is performance...


after doing a google image search i found many examples for both.....now i am really confused lol

 

Thanks for bumping this, I never got an answer one way or another but the truck has been running fine using the original orientation (fat ring towards the rear).

 

I always use the marks on the filter .

The fuel flows in the direction of the arrow.

I have had no problems

 

^^ same. Fuel flow in the direction of the arrow on the side of the filter itself.

 

According to what I just read, there wouldn't be any symptoms from putting the fuel filter the wrong direction, the fuel pump would apparently make up for it (and run your fuel pump to premature failure)

Is there any way to get a definitive answer to this? I am installing a new fuel filter and from what I thought I read before, the inlet is in front, and outlet in back, so flow faces the rear. But now I'm noticing the arrow on the filter is also facing backwards and looking this up again has led me to confusion now

 

From what the FSM shows, for what it's worth, it shows the filter installed with the fat end towords the front.

Note the letters EFI read front to back. The fat end of the filter is to the E in EFI, so, to the front.

Other than that, just have the fuel flow, IE the inlet from the pump, and the outlet to the Pulsation Damper on the fuel rail, according to the arrow on the filter.
I just saw a video about this. The INLET from the tank is the fat end. The outlet is the other (duh).
Why they have it bass-ackwards that way, with the inlet at the front, and the outlet at the back I have NO idea. Why did they make the line from the tank go all the way to the "front" of the filter when it's installed, when it's common sense to run the inlet, from the tank, to the back of the engine, and thus the filter. After all, the tank is at the back of the truck, behind the engine.

Does it matter? I dunno, but I would figger they put it in "The Book" for SOME reason. The last time I changed mine, I did it that way, and it's working good. At least it was before the inside fuse box caught fire...
Pat☺

 

Thanks! I'm not sure what the "fat end" is, the filter seems pretty symmetrical, but I do have it hooked up as described. Puzzles me too why they did it backwards, but if I had to guess, it would be because if it wasn't backwards then the route from the outlet (which would be in front now) to the dampener thing, the bends/curves would be too tight? Dunno, the least they could have done was provide more detailed explanation in the FSM..

 

The fat end= the end with the larger rim around it than the other end.