truck bucks in 3rd gear with gas so far down.
12-27-2009, 05:21 PM
#1
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truck bucks in 3rd gear with gas so far down.
when im in 3rd gear and the gas pedal like 1/4 way down my truck bucks but when i give it more gas it stops. when im on highway in 5th it will do it a little also. could this be a bad throttle position sensor?
12-29-2009, 04:07 PM
#3
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Well, I can safely say it has something to do w/ either air, fuel, or ignition!<-Joke. Make sure you don't have any Vac leaks. Then do an error code scan & give more info about the truck (how long since tune up, fuel filter change, last work done on truck, ect...) mikentiff might want to start his own thread to keep the info differing between trucks separate. Or who knows, maybe they'll be the same, but I doubt it. One's probably gonna be fuel & the other maybe........secondary air related (EGR).
Last edited by ymeski56; 12-29-2009 at 04:19 PM.
12-29-2009, 04:32 PM
#4
Hi-Rev Motorsports
A bad TPS will do this and also a malfunctioning MAP sensor...
the MAP is more likely to as the TPS will usually hesitate...but not always...
I would do as Y suggested and check for Vac leaks...especially the MAP sensor line...
I would pull it off and make sure it isnt clogged at the intake as well...
the MAP is more likely to as the TPS will usually hesitate...but not always...
I would do as Y suggested and check for Vac leaks...especially the MAP sensor line...
I would pull it off and make sure it isnt clogged at the intake as well...
12-29-2009, 05:31 PM
#5
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mine was doing about the same thing... i drove it and drove it for months like that.... about a week ago, it finally threw a cylinder #6 missfire... i changed the spark plug (just in case) and inspected the wire also... come to find out, i had a broken vaccum line that connects to the bottom nipple on the EGR solenoid.... you may want to take a look at that...
12-29-2009, 05:45 PM
#6
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Thread Starter
i did change plugs and wires and vac. lines recently. i had put a new map sensor on when i got intake cleaned and then like 1 month ago it failed causing it to misfire so i stuck old one back on and it ran fine. i am thinking TPS. well sometime in spring i might be taking out my engine to rebuild and build it up cause i got a rod knock. hopefully it wont be their when i put it back in.
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12-29-2009, 07:10 PM
#8
Hi-Rev Motorsports
just make sure you recon the rod and when having them grind the crank have them hold the tighter end of the tolerance....
then Chamfer all the oils holes especially around the oil pick up area...
use Royal Purple Break in and then when you swap it out for Synthetic Oil add a quart of Lucal Full Synthetic and call it a day....
Where Fords get the rattle on start up is the oil drains back to the pan so basically every time you start the engine it has to refill the oil feeds basically re-prime the system...
then Chamfer all the oils holes especially around the oil pick up area...
use Royal Purple Break in and then when you swap it out for Synthetic Oil add a quart of Lucal Full Synthetic and call it a day....
Where Fords get the rattle on start up is the oil drains back to the pan so basically every time you start the engine it has to refill the oil feeds basically re-prime the system...
01-05-2010, 03:05 AM
#9
just bought a truck that does this... you guys gave me some good ideas to look at.... never owned one of these 4.9s they sound fun..hah....mine has a rod knock on start up and has had it for like 8 years... but it runs like butt when you get on the gas hard
01-09-2010, 09:47 AM
#10
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Thread Starter
ok here's what i have noticed the truck doing now. it seems to only buck at 1600RPM in any gear. could it posibly be something with the distributor?