hesitation
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hesitation
I am new to the forum here but so far it has great info. I have a '02 4.6 f150 supercab. Resently when you get on the gas from regular driving speed it has a jerky hesitation. If you continue to put the pedal down it gets worse and the THEFT light blinks off and on until you resume back to cruising speed. It gets even worse when pulling a trailer or going up a hill. I recently replaced the fuel filter and it did not help. Any suggestions? The truck only has 58k on it.
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Joined: Nov 2004
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From: Salt Lake City, Utah
What codes. Surely them should be some stores engine codes. If you can find any, let us know what they are.
I can take a stab at what I think might be wrong, but I know almost nothing about they history of your vehicle.
Ok, there is a possibility that the Throttle Position Sensor is going out of range. This is not a common problem, but does somewhat match your description. And issue that is common is contamination or failure of the Mass AirFlow sensor (MAF). This sensor tells the computer information about how much air is going into the engine, and how dense this air might be. If this sensor fails, the computer cannot add the correct amount of fuel under changing conditions. This matches your symptoms as well. When you are cruising, your computer can default to the O2 sensor for accurate data, but the O2 sensor is not helpful when you are accelerating. MAF failure or contamination is especially likely if you have a K&N filter, or some other type of oil based air filter.
I can take a stab at what I think might be wrong, but I know almost nothing about they history of your vehicle.
Ok, there is a possibility that the Throttle Position Sensor is going out of range. This is not a common problem, but does somewhat match your description. And issue that is common is contamination or failure of the Mass AirFlow sensor (MAF). This sensor tells the computer information about how much air is going into the engine, and how dense this air might be. If this sensor fails, the computer cannot add the correct amount of fuel under changing conditions. This matches your symptoms as well. When you are cruising, your computer can default to the O2 sensor for accurate data, but the O2 sensor is not helpful when you are accelerating. MAF failure or contamination is especially likely if you have a K&N filter, or some other type of oil based air filter.
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What others suggest are good ideas to start. CRC makes a MAF cleaner spray, I used that on mine recently. I also have a K&N. Not too impressed with the factory oiling of the K&N, I never re-oiled it and I and found a nice coating of oil inside the intake ribs, especially around the MAF. I wiped it out with a rag.
When I bought my truck 5 years ago it did the same thing you describe. I thought it was transmission, but I did a full tune up: plugs, wires, coils, fuel filter, and the problem went away and has stayed away all this time.
Recently I noticed a reduction in performance, so after reading here and corresponding with Bear River, I decided to replace my pre-cat 02 sensors, and clean my throttle plates/body. Turns out it was a great idea and my truck is now running better than ever.
When I bought my truck 5 years ago it did the same thing you describe. I thought it was transmission, but I did a full tune up: plugs, wires, coils, fuel filter, and the problem went away and has stayed away all this time.
Recently I noticed a reduction in performance, so after reading here and corresponding with Bear River, I decided to replace my pre-cat 02 sensors, and clean my throttle plates/body. Turns out it was a great idea and my truck is now running better than ever.
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What others suggest are good ideas to start. CRC makes a MAF cleaner spray, I used that on mine recently. I also have a K&N. Not too impressed with the factory oiling of the K&N, I never re-oiled it and I and found a nice coating of oil inside the intake ribs, especially around the MAF. I wiped it out with a rag.
When I bought my truck 5 years ago it did the same thing you describe. I thought it was transmission, but I did a full tune up: plugs, wires, coils, fuel filter, and the problem went away and has stayed away all this time.
Recently I noticed a reduction in performance, so after reading here and corresponding with Bear River, I decided to replace my pre-cat 02 sensors, and clean my throttle plates/body. Turns out it was a great idea and my truck is now running better than ever.
When I bought my truck 5 years ago it did the same thing you describe. I thought it was transmission, but I did a full tune up: plugs, wires, coils, fuel filter, and the problem went away and has stayed away all this time.
Recently I noticed a reduction in performance, so after reading here and corresponding with Bear River, I decided to replace my pre-cat 02 sensors, and clean my throttle plates/body. Turns out it was a great idea and my truck is now running better than ever.
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What I did was spray the plate with the cleaner and gently scrub it with a tooth brush, then wipe the gunk out with a red rag. I did this until the plate was real clean looking and got in and around the whole area as much as I could. Seems it was a good thing to do cuz at 115k miles, there was a good amount of gunk on the plate and surrounding area.
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Well last night I cleaned the MAF and checked the EGR and it looked fine. Anyone else have any new suggestions. I did not tackle the trottle body yet, but with only 58K do you all think that might be the problem?
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From: MAYBEE MI
you may have some lean codes without setting off the check engine light. i have experienced hesitation same way you described and found after weeks of checking various component that the fuel injectors were plugged up with rust on number 3 cylinder. no check engine light but when i ran for codes it gave me a lean code for
3 cylinder. after checking plugs, wires, and vacuum leaks or plugged vacuum lines i found no. 3 injector as well as the rest of them clogged with rust. apparently from a gas station fill up i presume. changed all injectors, cleared code and recheck no more
hesitation. hope info helps. ed
3 cylinder. after checking plugs, wires, and vacuum leaks or plugged vacuum lines i found no. 3 injector as well as the rest of them clogged with rust. apparently from a gas station fill up i presume. changed all injectors, cleared code and recheck no more
hesitation. hope info helps. ed
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you may have some lean codes without setting off the check engine light. i have experienced hesitation same way you described and found after weeks of checking various component that the fuel injectors were plugged up with rust on number 3 cylinder. no check engine light but when i ran for codes it gave me a lean code for
3 cylinder. after checking plugs, wires, and vacuum leaks or plugged vacuum lines i found no. 3 injector as well as the rest of them clogged with rust. apparently from a gas station fill up i presume. changed all injectors, cleared code and recheck no more
hesitation. hope info helps. ed
3 cylinder. after checking plugs, wires, and vacuum leaks or plugged vacuum lines i found no. 3 injector as well as the rest of them clogged with rust. apparently from a gas station fill up i presume. changed all injectors, cleared code and recheck no more
hesitation. hope info helps. ed
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From: N. Fort Myers,FL
It says that he changed them.