Sputtering/hesitates when accelerating
Thread Starter
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Joined: Nov 2025
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I had got a new air filter and have cleaned the mas air flow sensor ! I’m trying to look up throttle body manifold and all that comes up is intake manifold is that what it is ??
rent a fuel pressure gauge or buy one. They are cheap enough. You need to do a lot of testing before firing the parts cannon at it. If you aren't sure, quit while you are ahead and take it to a reputable shop
Last edited by djfllmn; Nov 21, 2025 at 06:42 AM.
98 F150 5.4L E40D/4R100
Joined: Nov 2006
Posts: 28,519
Likes: 7,630
From: MI
SERIOUSLY THANK YALL FOR REPLYS
the fuel pump was changed because my sister said the day after she started driving it the fuel pump went out she had someone change that ( he only changed the pump nothing else (19yrold kid))
also I had changed the fuel filter well my buddy did (motorcraft filter) the issue stopped for maybe 2 weeks then started again! Some one said filter might be dirty again! Unit is facing the right way but I cannot speak about the fuel pump or anything else
it does Not throw a code for anything else besides a lean code
I ordered spark plugs and coil packs from Amazon 8plugs 8coils motorcraft as well they should get here today
i was going to change them and see if that still Happens before I do anything else
SO THIS HAPPENS at 1500 through 2000 rpm 40 thru 50 mph more or less It does not have a rough idle or nothing else out of ordinary and it does not have high rpm’s
the fuel pump was changed because my sister said the day after she started driving it the fuel pump went out she had someone change that ( he only changed the pump nothing else (19yrold kid))
also I had changed the fuel filter well my buddy did (motorcraft filter) the issue stopped for maybe 2 weeks then started again! Some one said filter might be dirty again! Unit is facing the right way but I cannot speak about the fuel pump or anything else
it does Not throw a code for anything else besides a lean code
I ordered spark plugs and coil packs from Amazon 8plugs 8coils motorcraft as well they should get here today
i was going to change them and see if that still Happens before I do anything else
SO THIS HAPPENS at 1500 through 2000 rpm 40 thru 50 mph more or less It does not have a rough idle or nothing else out of ordinary and it does not have high rpm’s
Don't get coil pacs , that truck doesn't use them. 5fours never used coil pacs. That's a older 4six and 4two thing. You have a COP system (CoilOnPlug). Replace w/DENSO coils. Those are OEM which boast the proper thermal protection and dual build magnet set ups. RA carries them. You can use Motorcraft coils as well , but they're the same thing for more money.
It's a very common low grade misfire and exactly how they fail.
Last edited by Jbrew; Nov 21, 2025 at 08:26 AM.
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Cleaning is the first thing I would do before replacing parts.
Thread Starter
Junior Member
Joined: Nov 2025
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I think it’s fixed
So I had a buddy replace the plugs and coils he said
“there were 2 loose spark plugs and 1 loose coil) the 2 in the back so that’s why it was misfiring and sputtering also in the process of him doing that the EGR valve one of the hoses were disconnected! I bought a new one of those ! I drove it for almost an hour and up some hills and accelerated a handful of times and there was no hesitation or no slow response! Hopefully the problem was fixed but yes it was the sparks and coils not being tight
THANK YALL HONESTLY FOR YALLS ADVICE AND INFORMATION
“there were 2 loose spark plugs and 1 loose coil) the 2 in the back so that’s why it was misfiring and sputtering also in the process of him doing that the EGR valve one of the hoses were disconnected! I bought a new one of those ! I drove it for almost an hour and up some hills and accelerated a handful of times and there was no hesitation or no slow response! Hopefully the problem was fixed but yes it was the sparks and coils not being tight
THANK YALL HONESTLY FOR YALLS ADVICE AND INFORMATION
98 F150 5.4L E40D/4R100
Joined: Nov 2006
Posts: 28,519
Likes: 7,630
From: MI
Yeah that's a big problem with these (gen 10's), sparkplugs loosen up and shoot out of the cylinder taking the chamber threads with it. Good thing you caught it. Torque spec is too low from the factory. Spec needs to be at least 28' lbs or they will most likley vibe out.
Gen 11's were the opposite as they would get stuck snapping off in the chamber.
Gen 11's were the opposite as they would get stuck snapping off in the chamber.
Thread Starter
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now referring to the problem it’s been driving great accelerating great up hill or even during a hill when I accelerate!
Atlwast I know it has a new fuel filter/fuel pump/ spark plugs and coils / and tires
Quick question ! If the plugs were just put in with a ratchet as tight as he could go that would be fine right???
he didn’t use a torque wrench but this guy knows what he was doing
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From: KY.
well my little sis had some one do it but it was more of a favor than get paid or laid thing so I don’t think he actually did his best and the back 2 were lose and most of the plugs were white on top!
now referring to the problem it’s been driving great accelerating great up hill or even during a hill when I accelerate!
Atlwast I know it has a new fuel filter/fuel pump/ spark plugs and coils / and tires
Quick question ! If the plugs were just put in with a ratchet as tight as he could go that would be fine right???
he didn’t use a torque wrench but this guy knows what he was doing
now referring to the problem it’s been driving great accelerating great up hill or even during a hill when I accelerate!
Atlwast I know it has a new fuel filter/fuel pump/ spark plugs and coils / and tires
Quick question ! If the plugs were just put in with a ratchet as tight as he could go that would be fine right???
he didn’t use a torque wrench but this guy knows what he was doing
98 F150 5.4L E40D/4R100
Joined: Nov 2006
Posts: 28,519
Likes: 7,630
From: MI