[fourfive]

After doing a poor man's version of pressure testing my gas tank to troubleshoot a P0440 code, my overfill check valve & check valve gasket, located on top of the gas tank, seems to be part of the issue & hopefully THE only issue. Since I will be dropping my tank to replace those parts, I thought I'd take a page out of @Jhelms write up & replace my original fuel pump & gasket since the tank will be down.

Aside from the overfill check valve & fuel pump, I noticed there is also a fuel cutoff valve & gasket on the parts diagram but don't remember coming across any information about replacing that part as well while the gas tank was down. The part is only about $12 so I figured I'd go ahead and replace that too so I don't have to worry about any other gas tank maintenance for a while.




1. Anybody else replace the fuel cutoff valve when replacing the fuel pump (see pic below)?

2. The Denso 950-0100 fuel pump seems to be a common aftermarket option & is ~$80 vs the toyota fuel pump which is ~$240. It seems like in the fuel pump realm for 3rd gens, most have gone aftermarket. Has anybody gone with the toyota pump?

3. I remember hearing about some part that wasn't included with the aftermarket fuel pumps that was typically included with the toyota pumps? Any truth to this or bad information?




Toyota part numbers:
Overfill check valve: 77390-35010
Overfill check valve gasket: 77177-33010
Fuel pump gasket: 77169-60010
Fuel pump: 23221-46010
Rubber cushion for fuel pump: 23249-74610
or
Denso 950-0100

Fuel cutoff valve: 77380-26010
Fuel cutoff valve gasket: 77179-26010

Edit:
The overfill check valve only applies to 2001-2002 4runners

[TheDurk]

I just did my fuel pump when I did my frame swap, and my '99 doesn't have all that stuff. Besides the pump/sender assembly, there's just a breather tube which looks pretty trouble-free. The cut-off valve is a silly little thing inside that and I have never heard of one failing. No over-fill valve at all. I didn't even touch the cover. I only did the Denso kit, which was pump, strainer, the little hose, and hardware. The cushion, which was not included, was perfectly fine to reuse.

I think your question applies only to '01 and '02. Just trying to avoid confusion.

Here is the '99 tank:

[Toyotayoda]

P0440 is to generic a code, the definition is literally "problem with evaporative system". And without a $1200 smoke machine and a $3000 Techstream you are basically just guessing. There are really only 3 things that often fail in toyota evap systems, the vapor pressure sensor the charcoal canister, and the purge valve. Yes other things like tank seals and fuel fill tubes occasionally are bad, but it's rare. Check rubber hoses and fuel cap seal for visible cracks first, no need dropping the tank for a split vapor hose. I don't know voltage values off the top of my head but the Vapor sensor can be checked using a vacuum pump and a multimeter. if that checks out most probable is the charcoal canister, and if you are going to be dropping coin for the charcoal canister go ahead and get the purge valve as well. I've never had to replace an overfill check valve on any car in my career thus far.

[stir_fry_boy]

Originally Posted by fourfive

After doing a poor man's version of pressure testing my gas tank to troubleshoot a P0440 code, my overfill check valve & check valve gasket, located on top of the gas tank, seems to be part of the issue & hopefully THE only issue. Since I will be dropping my tank to replace those parts, I thought I'd take a page out of @Jhelms write up & replace my original fuel pump & gasket since the tank will be down.

Aside from the overfill check valve & fuel pump, I noticed there is also a fuel cutoff valve & gasket on the parts diagram but don't remember coming across any information about replacing that part as well while the gas tank was down. The part is only about $12 so I figured I'd go ahead and replace that too so I don't have to worry about any other gas tank maintenance for a while.




1. Anybody else replace the fuel cutoff valve when replacing the fuel pump (see pic below)?

2. The Denso 950-0100 fuel pump seems to be a common aftermarket option & is ~$80 vs the toyota fuel pump which is ~$240. It seems like in the fuel pump realm for 3rd gens, most have gone aftermarket. Has anybody gone with the toyota pump?

3. I remember hearing about some part that wasn't included with the aftermarket fuel pumps that was typically included with the toyota pumps? Any truth to this or bad information?


Attachment 226982

Toyota part numbers:
Overfill check valve: 77390-35010
Overfill check valve gasket: 77177-33010
Fuel pump gasket: 77169-60010
Fuel pump: 23221-46010
or
Denso 950-0100

As you can probably imagine, I have replaced all the gaskets and valve at the top of my gas tank. No need to replace the fuel pump. They rarely fail. You can replace it without dropping the tank anyway.

[LittleCaesar]

I still say it is the canister. Find a junkyard in the Peach State that has an 2002 and grab it.

Get the Metabo yet?

[JayRolla]

Denso makes the oem pump. You can wire a denso fuel pump from a Mitsubishi Evo 8-9. Oem quality and 190lph flow if you decide on turbo or supercharger in future. Guy on ebay sells them with harness for like $80. I just installed one few months back.

[fourfive]

Originally Posted by TheDurk

I just did my fuel pump when I did my frame swap, and my '99 doesn't have all that stuff. Besides the pump/sender assembly, there's just a breather tube which looks pretty trouble-free. The cut-off valve is a silly little thing inside that and I have never heard of one failing. No over-fill valve at all. I didn't even touch the cover. I only did the Denso kit, which was pump, strainer, the little hose, and hardware. The cushion, which was not included, was perfectly fine to reuse.

I think your question applies only to '01 and '02. Just trying to avoid confusion.

Sounds like you used Denso 950-0100 since it came with the additional parts & not 951-0001?

When you say cushion, are you referring to the rubber gasket looking thing in the diagram?

Were you having symptoms with your pump or did you replace yours due to easy access during your frame swap for preventative purposes?



Appreciate the tip about the cutoff valve. Guess the reason I haven't come across any info on it was bc they don't fail much. And you are correct, the overfill check valve does only apply to the 01-02 4runners. Will edit my original post.

[fourfive]

Originally Posted by Toyotayoda

P0440 is to generic a code, the definition is literally "problem with evaporative system". And without a $1200 smoke machine and a $3000 Techstream you are basically just guessing. There are really only 3 things that often fail in toyota evap systems, the vapor pressure sensor the charcoal canister, and the purge valve. Yes other things like tank seals and fuel fill tubes occasionally are bad, but it's rare. Check rubber hoses and fuel cap seal for visible cracks first, no need dropping the tank for a split vapor hose. I don't know voltage values off the top of my head but the Vapor sensor can be checked using a vacuum pump and a multimeter. if that checks out most probable is the charcoal canister, and if you are going to be dropping coin for the charcoal canister go ahead and get the purge valve as well. I've never had to replace an overfill check valve on any car in my career thus far.

Definitely doing my best to avoid the guessing game fixes. I've been following my FSM for troubleshooting my evap system. While the FSM doesn't mention using a smoke machine I do agree at it's effectiveness. My first attempt at making a homemade smoke machine was kind of a fail because it was windy making it hard to see the smoke, forgot the minerol oil that's recommended to make the smoke thicker & my compressor ran out of air & I didnt have an outlet nearby to recharge it. Will give my smoke machine another go after working out some kinks. Following the fsm guidlines i was able to rule out my charcoal canister by doing various pressure & vacuum tests using a mityvac hand pump. That being said I won't rule out the possibility of testing error on my part. The hoses "looked" to be in good condition but it's possible I missed a pin hole leak. Once I get my smoke machine working properly I will go over my hoses again. My vsv for pressure swithcing valve located on the charcoal canister on my 02 tested good using a multimeter & 9volt battery. Testing my purge valve is still on my list, just ran out of time this last weekend. Good looking out though.

Originally Posted by stir_fry_boy

As you can probably imagine, I have replaced all the gaskets and valve at the top of my gas tank. No need to replace the fuel pump. They rarely fail. You can replace it without dropping the tank anyway.

I was actually hoping it was anything but the overfill check valve gasket because I wanted to avoid messing with gas fumes & my tank. When i pressurized the gas tank via the purge port on the canister, i could hear air escaping near the overfill check valve on top of the gas tank. I tried feeling for it with my hand but there's not much room up there....& by pressurizing my gas tank I mean connecting a hose to the purge port & blowing into it since I had air compressor issues. I purposely kept my tank close to full so it wouldn't take much air pressure to pressurize it to .5psi per FSM but will have it on empty when I lower it. I tried spraying soapy water but since there is very little room, it was tough to spray that area and see what was going on without lowering the tank.

I agree, I haven't heard of many fuel pump failures but was thinking since I have close to 180k on my original fuel pump may as well replace it while I have access to it.

[fourfive]

Originally Posted by LittleCaesar

I still say it is the canister. Find a junkyard in the Peach State that has an 2002 and grab it.

Get the Metabo yet?

Definitely not ruling out the canister completely, just putting it on the back burner for now since it "passed" the fsm tests. If after fixing all the suspect areas that my troubleshooting reveals & my P0440 code is still not resolved, I will revisit my charcoal canister again for issues.

The metabo came in over the weekend & it looks to be good quality. The sucker is small compared to my Ingersoll rand which is a good thing & hopefully will have enough power to handle any of the high torque bolts on my 4runner. I haven't used it yet but will update your thread once I give it some range time.

Originally Posted by JayRolla

Denso makes the oem pump. You can wire a denso fuel pump from a Mitsubishi Evo 8-9. Oem quality and 190lph flow if you decide on turbo or supercharger in future. Guy on ebay sells them with harness for like $80. I just installed one few months back.

Good to know. I've read that Denso does make a good amount of OEM parts but also saw that there were some denso parts that were suspect but don't think I remember coming across any negative feedback about the denso fuel pumps for the 3rd gen.

[Jhelms]

Originally Posted by Toyotayoda

P0440 is to generic a code, the definition is literally "problem with evaporative system". And without a $1200 smoke machine and a $3000 Techstream you are basically just guessing. There are really only 3 things that often fail in toyota evap systems, the vapor pressure sensor the charcoal canister, and the purge valve. Yes other things like tank seals and fuel fill tubes occasionally are bad, but it's rare. Check rubber hoses and fuel cap seal for visible cracks first, no need dropping the tank for a split vapor hose. I don't know voltage values off the top of my head but the Vapor sensor can be checked using a vacuum pump and a multimeter. if that checks out most probable is the charcoal canister, and if you are going to be dropping coin for the charcoal canister go ahead and get the purge valve as well. I've never had to replace an overfill check valve on any car in my career thus far.

On the 01 and 02, the check valve is a very common item to have fail. Most common symptom is a gas smell around the back of the vehicle. This gives the same symptom as a loose gas cap / 442 code and not a 440 code. 100% resolved with replacement of the valve. A quick search shows it is a common failure on our gunners - so much so, camelback usually has a few in stock as they get calls on it often.

[JayRolla]

Originally Posted by fourfive

Definitely not ruling out the canister completely, just putting it on the back burner for now since it "passed" the fsm tests. If after fixing all the suspect areas that my troubleshooting reveals & my P0440 code is still not resolved, I will revisit my charcoal canister again for issues.

The metabo came in over the weekend & it looks to be good quality. The sucker is small compared to my Ingersoll rand which is a good thing & hopefully will have enough power to handle any of the high torque bolts on my 4runner. I haven't used it yet but will update your thread once I give it some range time.



Good to know. I've read that Denso does make a good amount of OEM parts but also saw that there were some denso parts that were suspect but don't think I remember coming across any negative feedback about the denso fuel pumps for the 3rd gen.

Non oem part store denso is trash. B stock parts sold aftermarket. Denso oem is the best in the market. So you must get the denso with oem part#. The Evo pump was cheaper than Toyota dibs they are in demand.

[fourfive]

Originally Posted by Jhelms

On the 01 and 02, the check valve is a very common item to have fail. Most common symptom is a gas smell around the back of the vehicle. This gives the same symptom as a loose gas cap / 442 code and not a 440 code. 100% resolved with replacement of the valve. A quick search shows it is a common failure on our gunners - so much so, camelback usually has a few in stock as they get calls on it often.

I saw in your write up you also replaced the fuel pump for preventive purposes. Do you have any input on reasons for or against changing the fuel cutoff valve while the tank is down?

[TheDurk]

Originally Posted by fourfive

Sounds like you used Denso 950-0100 since it came with the additional parts & not 951-0001?

When you say cushion, are you referring to the rubber gasket looking thing in the diagram?

Were you having symptoms with your pump or did you replace yours due to easy access during your frame swap for preventative purposes?



Appreciate the tip about the cutoff valve. Guess the reason I haven't come across any info on it was bc they don't fail much. And you are correct, the overfill check valve does only apply to the 01-02 4runners. Will edit my original post.

Yes, I got 951-0100. Everything in the bottom half of the diagram below is in that kit except the cushion, which is the very bottom piece. It is rubber, and sits between the support bracket and the pump/strainer assembly. Mine was in perfect condition, but I have seen people say to change it. It is RUBBER, CUSHION(FOR FUEL PUMP) 23249-74610.

Old fuel pump was fine. Despite the poster above, the fuel pumps have failed on enough people in the forum I thought it was worthy PM since I had the tank out and had painted it. I am used to BMWs, and my son's '99 323i pump had just failed, as had my own 735i at about this age, so that made it a peace of mind thing. Kit was $79 on Amazon Prime.

[fourfive]

^Good info thanks. I'm going to add the PN# for the rubber cushion into the original post.

[LittleCaesar]

I think that through the dealer the valves are included with the new canister. I could be wrong here but thought someone had posted such some time ago.

If Xmas and new tires weren't around the corner I'd see about getting a Metabo for myself. Don't let the size fool you, it is a beast. Good luck with clearing the code.