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Is my fuel pump shot?

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Old 08-22-2012 | 06:21 AM
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Is my fuel pump shot?

Over the last week my 4runner hasnt been runnig very well, and by that i mean i feels like its out of gas, i thought the fuel filter was clogged so i replaced it 3 days ago and it was indeed very clogged but that didnt fix my problem, it starts happening after about 30 mins of driving and then it start to feel like its out of gas and wont rev higher than 3000rpm, which is makin me think my fuel pump is shot, would anybody else agree?
Old 08-22-2012 | 06:30 AM
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Or you have alot of Crap in your tank??? I had that problem had to change the filter on the pump like three times till it cleared up....
Old 08-22-2012 | 06:34 AM
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There is a filter in the tank as well that can get a lot of build up. Im assuming you have the 3.0, I am not sure where to check, but on a 22re, I pull the return lines off of the fuel rail and run it into a glass jar and see how fast it fills.

If the fuel pump is bad, I have had great luck using http://www.ebay.com/itm/New-Fuel-Pum...item35b6422050 they are expensive else where.
Old 08-22-2012 | 06:38 AM
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Yea when i took the old fuel filter off i blew through the new one and the old one and could barely blow through it but when pressure relieved abunch of literally black gas and black crumbs came out
Old 08-22-2012 | 06:47 AM
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I forgot to add that when this is happening ill pull off to the side or even at a red light, turn the truck off then back on right away then its fine for another 10-15 min then do it again turn it off then back on and fine again, i hate unreliable problems
Old 08-22-2012 | 08:24 AM
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You might have a lot of fine "crap" (I think that's the technical word) in the tank itself, which gets pulled up onto the "sock" filter. Once enough gets on that filter it chokes it off. When you turn it off, without flow to hold dirt onto the sock enough falls off to get you going.

This would ordinarily be a little far fetched, except your observation about the black gas and crumbs. You may need to remove the tank and clean it.
Old 08-22-2012 | 08:32 AM
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That was actually my next question is how and what do i clean it with? From what you guys are hearing does it sound to you like the pump is shot? How will i know if its shot by looking at it?
Old 08-22-2012 | 10:03 AM
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You won't. But your pump will run well enough to pressurize the system and start it. I've never heard of a pump that would run fine for 10 minutes and then just slow down; usually when they fail they just die and stay dead.

I don't know the best way (actually, I don't know any way) to clean a fuel tank. People talk about "steam cleaning," but I don't know what that involves. If it was mine, I'd try getting it out on a nice sunny day and cleaning it with a garden hose (sunny day so that it will dry before rusting).

Let us know what you find.
Old 08-22-2012 | 10:07 AM
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Might try the fuel pump test jumper and see if that makes any difference:
- http://www.4crawler.com/4x4/CheapTri...shtml#FuelPump

If it does, it may be either the Air Flow Meter or the Circuit Opening Relay cutting out and dropping out the fuel pump. If it does not help, then it may be the pump.
Old 08-22-2012 | 12:38 PM
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The truck has no problems starting up cold or hot, idles fine and revs fine until its been running for more than a half hour, im thinking the sock on my fuel pump is clogged and my tank is full of garbage after seeing what came out of my old fuel filter, im gonna try this on friday, ill take pics
Old 08-22-2012 | 12:48 PM
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You may have a "dead spot" in your TPS once it gets a heat soak on it. It's free to readjust and see if is within spec. Seen it before...
Old 08-22-2012 | 12:52 PM
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mine had this problem too it just seems like it would do it when i was a little below a half tsnk, if it was over half i never had an issue, turned out too be just crap in the tank, drain your tank, new fuel filter, clean your sock
Old 08-22-2012 | 09:49 PM
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Yea mine seems to only do it right around half tank too no problems otherwise, im tryin to make sure the tank is empty by friday so i dont have to drain anything else, should this fix improve my gas mileage aswell?
Old 08-22-2012 | 10:05 PM
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I've got a 1995 4Runner doing the exact same thing. that's y i'm on here!!
Old 08-22-2012 | 10:07 PM
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Bought it a DEA drug seizure auction about 2 months ago. Don't know how long it sat, but stickers have been out 4 2 years.
Old 08-24-2012 | 06:45 PM
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So im just about to lower the fuel tank but its still loosly in position, stuck up front and the hose clamp on the bottom of the filler neck was spun on backwards and i cant get at it to loosen it or im sure it would come down, has anybody removed their driveshaft in the back and slid their tank out sideways?
Old 08-24-2012 | 06:59 PM
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Originally Posted by scope103
I don't know the best way (actually, I don't know any way) to clean a fuel tank. People talk about "steam cleaning," but I don't know what that involves. If it was mine, I'd try getting it out on a nice sunny day and cleaning it with a garden hose (sunny day so that it will dry before rusting).
I clean mine with white vinegar and I have several other links of cleaning it on my 88 Runner build. It will take a few days Then coat it with Red kote.


I have not removed the driveshaft or dropped a pick tank from the underneath. I pull the bed as the hose connections are tight and hard to get to that way for me. Bed bolts can be tough, so I start a few days of soaking them in PB Blaster.
Old 08-25-2012 | 03:57 AM
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turn you key as fas as you can with out starting the truck you should her like a faint buzz, thats your fuel pump turning out if ya dont her it it dont work
Old 08-25-2012 | 06:43 AM
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Originally Posted by 86yotaaa
turn you key as fas as you can with out starting the truck you should her like a faint buzz, thats your fuel pump turning out if ya dont her it it dont work
It should not work that way. The COR won't close until it gets the STA signal, which is the same signal that turns the starter. I sure can't hear my fuel pump over the sound of the starter.
Old 08-25-2012 | 08:27 AM
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I'm with the "gunk in the tank" crowd. Been there before! Luckily, our yotas have drain plugs on the tank, so... I would drain all the fuel (you will prolly notice some nasty stuff toward the end. Then drop the tank, next... I take a couple rags to soak up what ever is left in the bottom... after you get as much fuel as possible out, vinegar does a good job of cleaning any nasty thick stuf caked in the tank, scrub, scrub, scrub! after all that is done, I take a garden hose to it, and flush the sucker out fully. Next take a shop vac to the inside to get any water out, and then a couple more rags to saok up whatever the vac didnt get.
Let it dry for at least a few hours (good time to crack a beer) Rhen clean the sock, put the pump back in, then the tank, add one can of dry gas, and fill the tank. All should be good after that.


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