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Discussion Starter #1 (Edited)
I recently changed the original "lifetime" fuel filters on two 4.1 Rav4's -- a '99 (189K miles) and a '00 (185K miles):


- the '99 had been experiencing some hard-to-nail-down performance issues (a bit sluggish under heavier loads, ie accelerating onto a freeway via an uphill ramp)
- the '00 had normal performance and no apparent issues​

(Note: I know there is a lot of discussion on this forum and others regarding the actual design life of a "lifetime" filter element, as well as what the design assumptions may be. In any case, the filters are out, so I offer this as commentary on the process and documentation of the results.)

The fuel filter is easy to change, though you have to remove several components in the front left side of the bay to get to it. There are many videos on how to do this (for example, https://www.youtube.com/watch?v=V7Fdnjoj2zM"). The only tips that I would add to these if you decide to change your filter are:


1.) Remove the charcoal cannister to give yourself more room to turn the bottom connection (which is a flare nut).
2.) Do not cut corners and **definitely** use a flare-nut wrench on the bottom connection to prevent twisting the fuel line.
3.) Rub a little clean engine oil on the bottom connection (flare nut threads) before installing the new filter and be sure to back it off while threading to be sure you're not cross-threading.
4.) Torque specs are 22 ft-lbs for the union (banjo) bolt on top, and 21 ft-lbs for the flare nut on bottom (note: you will need a crowsfoot or some other specialized tool to measure torque on the flare nut connection; I didn't have that, so I pulled it tight with a flare-nut wrench, and haven't had any leaks.)
5.) The Toyota fuel filters come pre-seated in a new bracket and with the two required crush washers, which is nice.



I cut open the fuel filters after a few days. What do you guys think? I think they actually looked pretty darn good for being the original filters.

However, the filter from the '99 was contaminated with some kind of gel or jelly-like substance that poured out with the fuel when I back-flowed it. I don't know what on earth it is. The substance had higher density than the gasoline and a different polarity (it kept to itself in lava-lamp like blobs, and would completely assemble into a single blob if given the chance!)

Not surprisingly, that "lava-lamp" Rav (the '99, 188K miles) experienced an significant performance boost from the filter change. The other Rav ('00, 185K miles) also have a slightly "zippier" feel with the new filter.

What do you guys think of the filter media? Any ideas on what the substance is? The pictures of the cut-open filters are after a couple days of evaporation, and so the media was "dry".














Difference in de-pressurization results:

Lastly, I wonder about this: the lava-lamp Rav didn't de-pressurize the same way as the other Rav. After I disconnected the fuel pump's electrical connection and removed the gas cap, the uncontaminated Rav started up and ran for a few seconds before dying out. When I depressurized the top connection (outlet fuel line), there was no spray and just a little leaking.

However, the lava-lamp Rav didn't even start after disconnecting the fuel pump connection and removing the gas cap. The pressure on the outlet line was also much higher, and there was some fuel spray, and more fuel leaked out when I de-pressurized the connection compared to the uncontaminated Rav. Would this be due to restricted flow in the filter only, or something else? Below is a picture of a new filter with light pink, clean media.

 

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Nice write-up! Thanks for taking the time to share it. I don't know enough about filters to say one way or the other. I've heard of fuel gumming up with fuel additives. I've only ever changed one pressurized fuel line filter before and I didn't notice any power gains or issues with start up. It started, died , then started and ran. No sweat. I'd be interested to peek inside of my filter.
 

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If I had to GUESS, I would GUESS that the blob was gelled fuel. Alcohol, gasoline and some water can cause that, I think.

I had a 92 RN Truck with a 22RE that started to go weak on full power acceleration. I replace the fuel filter on it, very similar to the RAV filter, and it fixed the problem. That one had about 220K miles on it. I put a new filter on my RAV when I did the motor swap. Not that the old one had problems, but just as a "while I'm in there." I think the sock on the pump probably filters out 99% of the crud in the tank.
 
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