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I found this article on Supramania and thought it was interesting. I have been looking at DYI maintenance for the Tundra, since I will be picking mine up on Thursday.

Interested on what the feedback will be. :)

The great fuel filter myth.
Written by Jim Hopkins, Toyota Tech Adviser
Feb 08, 2004 at 04:00 AM

When Toyota Engineers first developed their electronic fuel injection (EFI), they were searching for a maintenance free, self regulating fuel system that would continually maintain itself in optimum working condition, with NO maintenance. A fuel system customers would just love for it's low, low maintenance.

They knew that the fuel must be kept clean enough to pass freely through the fuel injectors, etc. without any clogging at all. For this dedicated filtering purpose "Nippondenso" developed a very special fuel filter with over ten times the filtering surface of any previous automotive fuel filter. It is inside a very strong, rust proof metal container with high quality threaded fittings, to withstand the high fuel pressures of EFI. The filter medium is carefully pleated, so a huge filter area can be installed inside a compact metal container. It is a truly fantastic fuel filter! "State of the art"!!!

The Engineers explained it this way. Their studies had shown that in some areas the current (small) fuel filters showed anywhere between about 60% to 15% clogging after 50K km. Therefore they had previously recommended their replacement at the 50K km service, because they felt that in some parts of the world the fuel filters may not make it to the next service at 100K km with much reserve to spare. They had found however that, overall, North American fuel was relatively clean.

There would be even less contamination entering EFI cars fuel filters, because of the new, large filter sock over the fuel pump pickup tube, inside the fuel tank that was made quite fine to protect the high speed electric fuel pump required on EFI cars. This pick up filter sock was somewhat "self cleaning" due to the sloshing action of the fuel in the tank bottom, and most dirt would just slosh off and be captured in the bottom of the fuel tank where it could do little harm.

Unless, of course, someone dumped a full bucket of mud into the fuel tank. They reassured us that with the smaller fuel tank filler neck it was very doubtful that this would ever happen. In any case no
filter could ever hope to cope with a humongous, catastrophic amount of dirt entering the fuel tank, and that it would require removal and cleaning of the fuel tank anyway.

Now! Compare fuel filters! If the older style smaller) fuel filter had a filtering capacity of 100 then this new EFI fuel filter with ten times the filtering capacity would be rated at 1000. In an "imaginary"
comparison test we could assume that since the old fuel filters may show 50% clogging at 50K km, those fuel filters were possibly replaced when 50 of their 100 filtration units were clogged at the time of the
specified 50K km service interval.

At 50K km the older fuel filter car would have It's smaller fuel filter replaced with a brand new factory replacement fuel filter, according to the factory recommended maintenance schedule, so it's reserve filtering capacity would be restored from 50 to 100. Since the EFI car neither required nor received any fuel filter maintenance it's larger 1000 unit filtration area would now have only a reserve of 950
units.

At 100K km inspection, the same recommended services would be performed, leaving the older fuel filter car with a fresh new fuel filter, with it's filtering capacity fully restored to 100. However, the EFI car would now have it's reserve lowered to 900.

After the 150K km service the older fuel filter car would be again restored to 100 units, while the EFI car would still have 850 units reserve.

At 200K km the older style would be restored to 100 units, and the EFI car would be left with 800 units.

At 250K km it would be 100 to 750reserve filtering units. At 300K km, 100 to 700. At 350 K km100to 650. At 400Kkm 100 to 600. At 450 K km 100 to 600.

And on and on………….Till finally at "one million" kilometres the older model would have it's EIGHTEENTH new fuel filter installed, restoring it's reserve filtration capacity once again to 100 units and
the EFI car still having it's original fuel filter would also have a 100 unit reserve filtration capacity.

Therefore it may, just may, be necessary to recommend that the EFI car should also have it's fuel filter replaced at one million and 50k km. We should live so long!

However, if the rate of accumulation of dirt was much lower than the predicted 50 filtration units per 50K km, during this one million km. test, then the EFI car may still have a very much larger reserve filtration capacity than we calculated. The lower dirt content would not have benefited the older, small fuel filter car at all. As well, the older style fuel filter would have contributed eighteen discarded fuel filters into a land fill, and at even five bucks a filter, cost
the customer "ninety" dollars in maintenance. Eureka! No more fuel filter replacements! Fuel filter replacement is finally just a relic of the past! WOW!

At this time (twenty years ago) fuel filters were completely deleted from all Toyota service maintenance schedules for all EFI vehicles. The oil change, air filter change, etc., remained, and were covered in
great detail in all factory service manuals, etc. But, all references to "fuel filter replacement" were deleted for all time from all factory service manuals. A whole half page of the factory service manual is devoted just to inspecting fuel pipes for any kinks or
deformation (including illustrations of a leaking fuel line). Text and illustrations of the precise, recommended placement of the rubber fuel line's spring hose clamp is fully covered, but absolutely NO mention
whatever of "fuel filter replacement". There is absolutely NO mention of any fuel filter replacement in any owner's manual (does anyone ever read them?) Do you think that the factory repair and owner's manuals
were trying to tell people something??? Did you get the hidden message??

The fuel filter was considered to have a service life far exceeding the projected life of the majority of most of the vehicle's other components, and was fully expected to outlast the cars. Replacement of the fuel filter made much less sense than the replacement of the fuel tank or the replacement of the ignition key, or the trunk lid emblem.

Great! Parts people were instructed to anticipate virtually zero fuel filter sales. One less maintenance service problem??? Great! Wow! Customers would love this!!!

But, much to the dismay of many Engineers, fuel filter replacement sales for EFI equipped cars remained telatively high. Why? Discarded fuel filters were reclaimed, opened up and found to contain almost no
dirt at all. Why were people replacing them??? The best laid plans of mice and men often go astray! Who knew why???

There was great concern that there was a high risk involved because some dirt could accidentally enter the fuel system, downstream of the fuel filter during the fuel filters replacement, and damage the downstream fuel injectors etc. There was also concern that all fuel line fitting gaskets, etc. would not be properly replaced with new ones, and that the fittings torque might not be correctly reset to factory specifications, as this was a very high pressure EFI fuel line.

This part of the EFI system was intended to be serviced "only" by trained mechanics, yet it was apparent that it was being serviced by people who, clearly did not know what they were doing. There were many complaints that replacement fuel filters were much too expensive, and much too difficult to replace. Why were people still replacing them??

Nobody seemed to know.

Believing that the fuel filters were too highly visible they were painted black, and the Engineers tucked them up under the intake chamber where they were very difficult to see or service, on the 7M-
GE models, to discourage needless replacement, but people kept on replacing fuel filter, despite the difficulties. Why???

It was suggested that a sticker be applied to warn people not to replace the fuel filter. This had been done previously to discourage needless spark plug replacement. The warning sticker helped, but many
people simply ignored the warning sticker and replaced the spark plugs anyway. Another very hard to break habit, that still continues today. Nobody wanted to commit to stating "NEVER" replace fuel filters, as
that's a very, very strong statement. Should the sticker read:

WARNING! Replace fuel filter every one million kilometres, or 25 years, whichever comes first!

I think a sticker on the fuel filter stating: Warning! "This is not a fuel filter", may prove to be more effective.

Do you think that fuel filter replacement is genetic?? My father always replaced his spark plugs and fuel filter, and I am fully committed to continue replacing mine too, and to the preservation of this fine family tradition. I don't know???? I just can't explain why
people insist on performing these seasonal, cultural, fuel filter rituals. It must be passed down from father to son as it's been going on for over 20 years! No warning sticker can ever overcome that kind
of dogged determination.

Why were people in North America still replacing these costly and difficult, and risky to replace fuel filters with NO instructions or any valid technical reasons for doing so??? It soon became apparent
to the Engineers that fuel filter replacement was so deeply ingrained into the North American culture that people just could not break their highly addictive fuel filter habits.

I had many phone calls: "Where the hell is the dam fuel filter any way?? What lame brained idiot put the fuel filter up there where I can't even get at it? He sure didn't know a dam thing about what he was doing! I could sure teach him a thing or two about engineering
cars." All I could say was " Why are you replacing the fuel filter?? Why?? The answer was usually " I always replace fuel filters. I won't ever risk having a fuel filter plugging up. So I asked, "Have you ever had one plug up???" Of course not stupid! Because I always
replace them. That's why" How can you ever argue with such success???

I suppose that if people derive some deep inner spiritual satisfaction by performing their traditional "fuel filter replacement" ritual, they
are free to continue to do so! it's a free Country!! But I really wonder why they insist on doing it??

Instead of applause, the poor Engineer receives insults!

I see from reviewing many of the posts on this site that the grand tradition of fuel filter replacement continues on unabated. It continues to be, by choice, the first recommended line of attack, to resolve almost any performance problem. I see posts from owners whose crankcase breather pipes must be so badly clogged with hardened crud that a "Roto Rooter" couldn't clear them (engine oil forced out
through the distributor??), I'll bet those same vehicles have probably had their fuel filters replaced. WHY? I have never, ever seen the replacement of a fuel filter successfully resolve any problem. Why do people always recommend first replacing the fuel filter??? Any suggestions????

I suspect that with tens of thousands of Toyota fuel filter sales, that a great many people are accumulating a nice nest egg to finance their early retirement. Americans spend many millions of dollars a
year on fuel filters. Would this money not be better spent elsewhere?

Perhaps a: "I gave up replacing my fuel filter so that a starving child could eat! , type of charity. Are fuel filters car owner's pacifiers, or security blankets??

I have cut discarded fuel filters apart , but I have never found anything inside that would ever restrict fuel flow. They appeared almost as clean as new inside?? If anyone has ever found one of these
"Denso" fuel filters that was ever actually clogged with dirt?? I would sure like to hear from you. They may exist?? But, I have not found any in twenty years. Please post if you have ever replaced a fuel filter because there was real evidence that the fuel filter was actually restricting fuel flow, and a replacement filter actually solved the problem by restoring the fuel flow. Please post if one of these fuel filters has ever passed a particle of dirt that damaged a
fuel injector.

I believe that the fuel filters very, very clean passing through these fuel filters as I have not yet seen a dirt clogged fuel injector.

I have found fuel pump residual check valves leaking from what I assumed was a spec of dirt (too small to see) as discussed in my previous post on fuel pumps, but I have always believed that this was because the fuel pump check valve was only protected only by the fuel pump intake filter sock, and not by the actual in line fuel filter.

The fuel pressure regulator never seems to leak residual fuel line pressure. I think it's because it's fuel is all completely filtered??? Anyone ever found a leak fuel pressure regulator???

I have only experienced one incident of fuel supply clogging, and that was because someone had attempted to repair a fuel tank by pouring an epoxy treatment inside to seal a damaged fuel tank The epoxy coating
peeled off and completely clogged the fuel pump filter sock, inside the fuel tank, but the fuel filter was still OK. I recommended replacement of the fuel tank and the fuel pump, as it had become overheated while sucking away on it's plugged inlet filter sock. Never
had a restricted fuel filter though.

Please post if you have ever found a restricted fuel filter????

Anyone???

SupraMania - The great fuel filter myth.

Written by Jim Hopkins, Toyota Tech Adviser
 

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Nice post, thanks for sharing...
 

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truly amazing.
something that isnt part of planned obselescence.
 

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My dad's Tacoma broke down and it was because of the fuel filter that was clogged.
Of course it is a 90 model (before they were even called Tacomas) with over 230,000 miles on it but it quit running because the fuel filter was so dirty.
 

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Back when I worked on cars for a living, I saw numerous fuel-injected vehicles with clogged fuel filters. I wouldn't let this guy advise me on how to maintain my car. His story might be based in truth (as far as the engineering goes), but reality is that filters can and do clog and it doesn't take 300,000 miles.
 

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Back when I worked on cars for a living, I saw numerous fuel-injected vehicles with clogged fuel filters. I wouldn't let this guy advise me on how to maintain my car. His story might be based in truth (as far as the engineering goes), but reality is that filters can and do clog and it doesn't take 300,000 miles.
I would agree with that....
 

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hi, excellent post
points given
print & save,& keep it in your vehicle.
when it comes time, & the advisor ask's you,
give to you service advisor the next time they tell you to change the filter.
but lok at his face when he read's it. i bet it will be a priceless molment! LOL
gorilla
 

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Discussion Starter #9
Definitly an interesting post for sure. I have had a clogged a fuel filter before, but that was in an 83 Ford Ranger. I'll be replacing the one in my Supra since it has been sitting for about 5 years. The Tacoma didn't have an easily replaceable fuel filter (in the tank) and was said to not need service?
 

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What kind of title is "tech adviser"? And why does he go on and on for 2,000+ words? His whole premise is based on some miracle filter that has ten times the surface of previous filters. I would rather read about the scientific characteristics of the gee-whiz filter material than some lame-***, middle school logic that "proves" a filter is viable for a million miles!

Here's some middle school math of my own: 1,000,000 miles at 19 miles per gallon = 52,631 gallons of gasoline. (A large gasoline tanker truck holds about 9,000 gallons.)
 

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I've seen many plugged filters over the years as a mechanic, we just had a 99 Jimmy that wouldn't run due to a plugged filter, original filter with 180k on it. Seems that most of the time it's GM vehicles, but that might be because that's what comes in the most. Some filters are better than others, like the Toyotas, but I don't mind spending a little for some peace of mind. This guy says he's never seen a filter cause a problem, I just think he hasn't seen enough.
 

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I don't mind spending a little for some peace of mind. This guy says he's never seen a filter cause a problem, I just think he hasn't seen enough.
+1

I'm all for peace of mind. I will be replacing mine this year along with a MAF and TB clean.
 

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I'm guessing that the underlying premises of the article's argument is that we are talking about:

1. gasoline from U.S./Canadian fuel stations,
2. vehicle fuel tanks manufactured from polycarbonate, and
3. fuel filters installed on tanks referenced in #2 above.

I have no doubt that there exists historical situations wherein a fuel filter has become clogged and has caused operational issues with a motor vehicle. However, I do question whether a modern fuel filter has been clogged under normal operation such that it created symptoms of fuel starvation that warranted replacement.

Think about it. What foreign matter has to invade your fuel tank over an extended period of time to create serious occlusion? You'd have to dump a shovel full of foreign matter in there to do it. What doesn't get excluded by the in-tank filtering media gets strained in the secondary pass by the inline filter.

Now, I know there's the group out there that likes to assert that the fuel filter's internal media "breaks down" over extended use. The problem, fellas, is that I have seen no empirical data to back up this assertion (which is par for the course when it comes to public forum data...). When/if you do, post up pictures with real-world facts to back it up and I'll be happy to reevaluate. The filter's internal structure is designed to survive gasoline immersion for years.

The only member who I think has any basis for asserting real-world experience with this is 2003bajatundra4x4ac. He spends time in MX and is one who can state for a fact what the worst of NA gasoline can be like.
 

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Most engine filters are inexpensive ............... replace them regularly!
 

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You can pick up all sorts of stuff from a gas station. That's how stuff gets in your tank. The US fuel supply might be relatively clean, but I've seen some nasty fuel filters and I don't think they were all due to vengeful x-girlfriends dumping sands into tanks. :p

Toyota used steel tanks in the early 80's, which is the time frame the article refers to. And yes, a corroding steel tank is a total nightmare...just start over. :cry3d:

I suppose if I had to pay someone to change my filter I might skip it...but for $15 and 15 minutes, what's the big deal? And if you look at what comes out of an old filter, it's pretty nasty. :cool:


I'm guessing that the underlying premises of the article's argument is that we are talking about:

1. gasoline from U.S./Canadian fuel stations,
2. vehicle fuel tanks manufactured from polycarbonate, and
3. fuel filters installed on tanks referenced in #2 above.

I have no doubt that there exists historical situations wherein a fuel filter has become clogged and has caused operational issues with a motor vehicle. However, I do question whether a modern fuel filter has been clogged under normal operation such that it created symptoms of fuel starvation that warranted replacement.

Think about it. What foreign matter has to invade your fuel tank over an extended period of time to create serious occlusion? You'd have to dump a shovel full of foreign matter in there to do it. What doesn't get excluded by the in-tank filtering media gets strained in the secondary pass by the inline filter.

Now, I know there's the group out there that likes to assert that the fuel filter's internal media "breaks down" over extended use. The problem, fellas, is that I have seen no empirical data to back up this assertion (which is par for the course when it comes to public forum data...). When/if you do, post up pictures with real-world facts to back it up and I'll be happy to reevaluate. The filter's internal structure is designed to survive gasoline immersion for years.

The only member who I think has any basis for asserting real-world experience with this is 2003bajatundra4x4ac. He spends time in MX and is one who can state for a fact what the worst of NA gasoline can be like.
 

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The guy is a dealership service adviser! When is the last time you met one of them that wasn't trying to rip you off? Yeah....me either.

I am replacing mine again this weekend. I'm at 107K and this will be my 3rd fuel filter. I've seen bad gas problems from this area so for $30 bucks it's really not a big deal. I, for one, would rather replace it early before it lets me sit on the side of the road.

While I appreciate what the guy is trying to say, it's like saying that timing belts these days are made so much better. So, you should just go without changing them.....until of course it breaks and destroys your engine. :beatsme:
 

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The guy is a dealership service adviser! When is the last time you met one of them that wasn't trying to rip you off? Yeah....me either.

I am replacing mine again this weekend. I'm at 107K and this will be my 3rd fuel filter. I've seen bad gas problems from this area so for $30 bucks it's really not a big deal. I, for one, would rather replace it early before it lets me sit on the side of the road.

While I appreciate what the guy is trying to say, it's like saying that timing belts these days are made so much better. So, you should just go without changing them.....until of course it breaks and destroys your engine. :beatsme:
$30? Was that the price of the filter or having someone do it? I changed mine and the filter cost like $7.

Agree with everything you posted by the way.
 

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I wonder too, how many of the clogged fuel filters people run into are an aftermarket replacement filter rather than the original Toyota filter? I don't see a big market for hiqh quality filters--it seems like most people that replace them grab a cheap one and then plan to keep changing them often (which may or may not happen as the car gets older/sold).

I think it would be nice if there were a better way to determine filter capacity remaining. It would be bad if people are constantly changing and throwing away filters with 90% capacity remaining. However, I find fault with any designer who tries to hide the filter and makes it harder to change because its supposed to last a "lifetime", which turns out to only be 100k.
 

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I've had to change my original fuel filter in my 85 Toyota pick-up due to it being completely plug up. Granted, the truck had 160,000 miles on it. What had happend was, the truck literally would not run anymore. You could get it started and idle, but as soon as you give it any gas it would struggle to stay running. It was starving of fuel. The moment I replace the fuel filter the problem completely went away. It was a day and night difference. The only thing I can attribute to the cause was the fact that I had modified the back of the truck and was running a steal marine gas tank that started to rust on the inside a little. I'm sure that's what clogged the filter. Well, that and the fact that it had 160,000 original miles. I also have an 85 4Runner with the original filter. It has 185,000 miles and has the original tank. I do get a little hesitation from time to time, but nothing like the pick-up. I plan on replacing the filter soon, but only because of the miles. I may not actually need to. The hesitation is probably related to something else since the truck is only and tired. If the filters were designed to last forever then that's great, but if not, they sure made it a PITA to change since the filter is mounted on the motor block... Just my 2 cents.
 
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