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:mecry:I have an '07 FJ with 109,000 km. Has been working and running excellent! out of the blue yesterday while on the high way it had no power. Would idle fine. In order to get any acceleration past 2nd gear i had to have accelerator to the floor. Max speed was about 90km/hour. The slightest hill and you had to down shift continually untill you were down to about second gear. Could this be the fuel pump starting to go? Fuel filter? HELP?
 

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:mecry:I have an '07 FJ with 109,000 km. Has been working and running excellent! out of the blue yesterday while on the high way it had no power. Would idle fine. In order to get any acceleration past 2nd gear i had to have accelerator to the floor. Max speed was about 90km/hour. The slightest hill and you had to down shift continually untill you were down to about second gear. Could this be the fuel pump starting to go? Fuel filter? HELP?
Any lights on the dash? Sounds like the FJ is in the mode where there is a falt.
 

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Discussion Starter #3
No lights on dash. That was my first thought as well. If it throws a code check engine light should come on. Just no power. engine sounds normal. Do the engine light come on if computer derates the engine?
 

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Sounds like something is tripping the FJ into a fail safe mode.
 

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Discussion Starter #6
Could a plugged air filter cause engine to go into fail safe mode? Have a k&n on and am in process of cleaning now. Was really plugged. Lots of dust on last few drives!
 

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Discussion Starter #8
That's what I thought. No light. Fuel pump? They usually fail outright don't they? Fuel filter? I did fuel up about ten minutes before this started. Maybe bad fuel.!
 

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I had a catalytic converter go bad and plugged up the exhaust pipe had no power at all
 

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You most likely have one of two problems: a fuel line restriction or an exhaust restriction. You say this power problem started about 10 minutes after you fuelled up. So I say it's fuel related.

Fuel Restriction
A plugged fuel filter, crushed fuel line or clogged pickup screen inside the fuel tank can all starve your engine for fuel. Enough fuel may get through for the engine to start and run at low speed, but when more fuel is needed it can't get through resulting in loss of power at high speed. The same kind of problem can also be caused by a weak fuel pump. But fuel pumps usually quit altogether when they fail.

Inspect the fuel line from the tank to the engine. If you don't see any obvious damage, try replacing the fuel filter. If that doesn't help, blowing out the fuel line with compressed air from the engine towards the fuel tank may help dislodge a blockage and debris from the pickup screen. If the pickup screen in the tank is clogged with rust and debris, the tank will have to be removed so the screen can be replaced and the tank cleaned.

Fuel pressure can also be checked by teeing a suitable gauge into the fuel line. If pressure is very low (refer to a manual for the specs), the pump probably will need to be replaced.

Exhaust Restriction
As for an exhaust restriction, the easiest way to check for this condition is to hook up a vacuum gauge to a vacuum port on the intake manifold or throttle body. If vacuum is low and continues to drop as the engine runs, it's telling you pressure is backing up because of a restriction in the exhaust. The most likely culprit is a clogged catalytic converter.

If the converter has overheated, it may have melted internally. This would restrict the flow of gases through the converter and create a serious backpressure problem that would cause a loss of power at high speed. If the blockage is complete, the engine may start then die and not run at all.

Other causes here may include a crushed exhaust pipe (a visual inspection should find this easy enough), a double-walled pipe that has collapsed internally, or a muffler that has become clogged with rust (rare, because they usually blow out). If you suspect an exhaust restriction, temporarily disconnect the head pipe from the catalytic converter (which is no easy task because the bolts will probably be rusted solid). If the engine now runs normally, you have an exhaust restriction. Inspect the converter and replace it if needed.

NOTE: If the converter is plugged, it failed because something else caused it to overheat. Causes include misfiring spark plugs and leaky exhaust valves. The underlying problem needs to be identified and corrected before the converter is replaced otherwise the new converter will suffer the same fate.
 

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The engine will not be in a protect mode without the AWL or CEL illuminated. The problem will be something the computer can not see. While cleaning the air filter, have you ever cleaned the mass air flow sensor? How about the spark plugs? Did the problem show-up right after a fueling?
 

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...Inspect the fuel line from the tank to the engine. If you don't see any obvious damage, try replacing the fuel filter. If that doesn't help, blowing out the fuel line with compressed air from the engine towards the fuel tank may help dislodge a blockage and debris from the pickup screen. If the pickup screen in the tank is clogged with rust and debris, the tank will have to be removed so the screen can be replaced and the tank cleaned...
Some great info and trouble shooting tips. However there may be one point of confusion. It's my understanding that the fuel filter is INSIDE the fuel tank. So replacing that probably requires dropping the tank as well. If it were me I'd probably try disconnecting the cats to ID an exhaust problem first. Just seems easier and less dangerous that messing with pressurized fuel lines and what not. I hope you find the problem, I'm really interested to see what it turns out to be.

I'm also curious about the fuel you purchased 10 minutes before this started. I've heard stories about underground tanks accidentally getting filled with diesel instead of gasoline. I don't know any way of testing/analyzing fuel though if you were to syphon a sample out. Although I'm sure you'd be hearing about it around town if fuel that bad had been dispensed.
 

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It's my understanding that fuel filter is INSIDE the fuel tank.

Right you are. The filter is inside the tank.
 

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10 mins after filling is awful coincidence. I had a similar thing happen to me years ago and it was water in the fuel.

DEWFPO
 

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Discussion Starter #16
Hey Guys
Thanks for all the great information it is very much appreciated!! Strange as it may sound it is running great again. My mechanic and I ran a bore scope into the tank and it looks like water might have been the issue. There were a few drops left in the bottom of the tank! Whew!
 

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Good to hear she's running fine now. Thanks for letting us know what the problem was.
 

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Sorry to bring up an old thread however i just ran into a similar issue...

After filling up not even a few moments after driving the motor was running very poorly, hardly any power, would stall if idled, had to keep up revs just to keep it running and 5 more mins after that it just died and couldn't get the motor to idle anymore.

Though as far as I've read fuel octane doesn't matter it is my first time putting in 87 (mistakenly) and prior always used premium.

I have a feeling that it's the fuel filter that got plugged up since i ran down the tank to almost the first line on the gauge and i never have since i owned it.

Any ways, I'm just tossing my problem on here to have it hopefully resolved tomorrow and other member's can benefit from it.
 

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10 mins after filling is awful coincidence. I had a similar thing happen to me years ago and it was water in the fuel.

DEWFPO
Leadfree gasoline should absorb water and just burn it off. If you think that's what it could be put in a couple of ounces of STABIL and it will cause the water and ethanol to reorganize with the actual lead free fuel and be a better burn, but don't overdo it. It will not hurt your fuel.

I think the most likely culprit is your converter. Especially if you have noticed your gas mileage degenerating over the past month or so. Gas mileage will go down and down and then nothing as it plugs up.
 

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