rage1187

First time poster. But been a lurker. I have read all that i know what to type. member of other board forums but figured i would venture out and about. i can give a brief description on what all i have experienced but if you dont feelt like reading all of that then skip forward.

here is what i have,,,,,,04 FX4. 5.4 3v

here is what i done cuz its a long boring story.

when i bought the truck it bucked and kicked, and threw the wrench light. Well 6 hours later and 7 broken plugs later i got that fixed. replaced the plugs with motorcraft plugs. replaced 1 of the COP's. Replaced fuel filter. Truck ran fine after that expect for the problem i have having now. I have enroute a S&B CAI and i have my X3 SCT tune/ programmer just waiting to be installed.

my problem.

At first it would do this when i was in overdrive. You would crest a hill at 55mph, would let off the gas to maintain the speed. once you got at the bottom of the hill you would apply throttle to keep the 55mph speed and thats when the truck would bog down. thats the only way i know how to describe it. it bogs down and the exhaust note changes, and you can feel the vibration throughout the whole truck. you apply a little bit of gas to get it out of it and it comes out of it. then the other day in town, i was at a red light. it turned green and i took off at a normal take off. and it done it. i held the throttle to see if it was a tranny related problem. kept the bog down sound and vibration but shifted fine. it never missed a beat on the shifts and it never bucked or nothing like that. its a weird sound. one minute your cruising down a back road on an open stretch and come to a hill on the downslope and then it happens. im at a loss.

and im just thinking outloud,,,,,,,i had a broken plug...so when i changed them could it have messed up the cats? when you mash the gas, the truck just flat out ****s and gets now. no hesitation non whatsoever now. only when your babying the truck and trying to drive i guess what i would call normal. shifts fine...idles fine... no engine codes are being thrown. only codes i have had with the truck since me owning it was when i first bought it, it had that misfire on CYL 5. got all that fixed. then i had some camshaft position sensors being thrown on both heads. fixed that. no codes since. when it bogs down it doesnt throw a code or nothing. so help a brother out. cuz this truck is starting to try my patience. i take care of my vehicles. it has motorcraft oil and motorcraft Oil filter. motorcraft fuel filter. plugs/ COP all Motorcraft. i need help.

primalurges

What about a fuel problem? I own a 96 vette that when its low on gas and you drive it a bit aggressivly it boggs down until you let your foot off the gas. What I'm thinking is maybe a fuel supply problem especially if you're experiencing this primarily on hills. I also used to have a jeep that would stall over speed bumps and found the problem to be about 2 gallons of water that somehow made it intothe fuel tank, the speed bump would mahe the water bounce up fromthe bottom, sucked into fuel system and result in a stall. If you're all out of ideas i would run your truck as empty as possible, drop the tank, empty it and look for water sitting onthe bottom.

Turkey Hunter

Im thinking that the bogging down is because your torque converter is locked while your in overdrive. When you give it a little gas it unlocks and its like its down shifting. If this is the case then it is perfectly normal

tekmunki

I had the same issue when cops were going out, after 2 went out I ran a whole new set.

Natually when you feel the 'shudder/shake' your first instinct is to let off the gas, I found by gunning it (risky I know) it would force it to throw the code and tell me which cop was missing. There's some tolerance before it will actually give you the code, chances are, if you replaced 1 and still have issues, you probably want to do the rest- then again, it could also be throwing money at a problem blindly.

I grabbed my set of cops (8) from amazon.com for around $170.

rage1187

i guess i could try that next time it acts up....gun it. i know when you punch it now, there is no hesitation at all. no pinging, nothing. she just gets up and goes now. not like it did before. but ill try it. its better than tossing money at it like you said. the only other thing i know to do is to drop the exhaust from the mainifolds and hollow out the cats.

Evil_E

I wouldn't do that unless you really want the truck to run like crap forever.

rage1187

i have a tune already for it. just would have to upload it and flash it. so i would be tricking the ecu in thinking im getting good readings and wont trip the CEL.

Evil_E

I wouldn't do that unless you really want the truck to run like crap forever.