My 4.6 idles rough. Not bad, just not as smooth as it should. It has new plugs & wires.

 

When my 97 5.4 has rough idle, is usually have to clean the fuel injectors. My experience has shown success in purchasing Chevron Techron FI cleaner and pouring in the tank near empty. Fill to half a tank. Also I usually use a spray type intake cleaner at the same time. This is the stuff you spray down your engine's throat. Follow the directions on the can. Usually you spray a whole can in while running the engine. I generally do this service every 7-10K miles. Works so far!

Good luck!

Darin

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97 F150 Lariat 4X4 Ext. Cab. 5.4, AT, Tow Pkg, bedliner, white/grey 2tone w/ grey leather, Fact. CD changer, Gibson Side Swept, K&N, Bosch Platinum +4's,Michelin LTX 265/70 16, S/D Triton V8 emblems, Both doors cracked, Piston slap quieted by Mobile One & Slick 50 Synthetic.

 

Hello:

I have a 1997 4.6L Lariat too. I am getting a little rough idle also (not all the time, sometimes worse than others). Lately I have also been getting some ping. Have cleaned the MAF sensor and that helped somewhat (I am running a K&N FilterCharger) but still there a little. I am also using Bosch platinum +4 sparkplugs. Do either of you run aftermarket plugs or are your original MotorCraft platinums still in?

Thanks,

Rick K.

 

rickstruck,

check out my sig. for upgrades. also ordered a SVO (Powerdyne) supercharger to be installed. This will be later rather than sooner if gas prices continue to spiral out of control.

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97 F150 Lariat 4X4 Ext. Cab. 5.4, AT, Tow Pkg, bedliner, white/grey 2tone w/ grey leather, Fact. CD changer, Gibson Side Swept, K&N, Bosch Platinum +4's,Michelin LTX 265/70 16, S/D Triton V8 emblems, Both doors cracked, Piston slap quieted by Mobile One & Slick 50 Synthetic.

 

I am running Autolite plugs W/ Motorcaft wires. Both were just replaced and it still does it. I just installed a K&N air filter & that seemed to help (I think).

 

I'll second the fuel injector cleaner idea! I put on a lot of highway miles so I thought the engine would stay clean. I've been getting a worse and worse rough idle lately though. So I put in some of the cheap ($1.99) Gumout injector cleaner and the idle has smoothed out a lot! I wonder if it will help the gas mileage. I'll have to watch the next couple of tanks.

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2000 XL 4.6 5spd 2WD reg-cab long-box 3.55 LS 265/75/16 Chestnut (not 2-tone) Raven-Cap (and a '66 GTO with a '73 455, both combined cost less than a Lightning )