you may have a bad coil---take a pair of rubber handle plyers & remove the spark plug wires 1 at a time---when you pull off a plug wire you should notic the truck runs even worse---the one you pull off & it doesnt change the way it runs--that is the cylinder that has the problem
IIRC these are a coil over design. meaning the coil is over the plug. the coil should have one 8mm bolt holding it on the lower intake manifold. remove the coild to get to the spark plugs. look by the fuel injectors, coil should be just next to it or very close. coil usually says motorcraft on it and circle in design.
Most of the 4.6 Litre engines have some form
of plastic cover, mine was held in place with two 11mm nuts at the front
and press-fit connection at the back. Remove this cover to gain access
to the spark plugs. You may need to disconnect the air hose going to the
throttle body and some additional vacuum hose connections. Mark them
with masking tape and numbers if you have any question about
re-attaching them correctly. Along each side of the intake manifold you
will see 4 round coils held in place with a 7mm bolt on each one. Remove
the 7mm bolts from each coil. Each of these coils has a connector that
will be disconnected by pinching the connector to release the catch and
pulling gently. Do not worry about marking them unless the wire harness
has been modified. The factory wire harness keeps the connectors next to
the correct coil.
Remove each coil and plug connector by gently turning the
unit to break the rubber loose from the manifold, then pulling up on the
coil/plug connector as a unit. Do not be alarmed if the rubber boot
cover comes off, you can easily reattach it to the coil. Once the coils
and rubber boots are removed, use your compressed air source or vacuum
to remove as much debris from around the spark plugs as possible.
Warning: Wear Eye Protection when using compressed air.
Remove the spark plugs using the 5/8" spark plug socket,
swivel, extension and ratchet. Some engine installations may require
additional extensions or swivels to get the back plugs removed. It
normally takes just an 1/8 turn to break the plugs loose and then about
4-6 full turns to fully remove the spark plugs. If the plug does not
come out with the socket, use the magnetic pickup tool to pull
the plug out. You will not be able to reach it with your fingers.
Using the feeler gauges gap your new spark plugs to the
correct gap for your vehicle. A typical
spark plug gap for this engine is .054 inch. With the plugs gapped, fit
the rubber fuel line to the top of a spark plug and then apply a small
dab of anti-seize compound to the plug threads. Work the anti-seize into
the threads a little bit and then insert the plug into the engine. The
rubber fuel line will prevent you from cross-threading the spark plug
and you should be able to turn the plug in about 3/4 turn or more
easily. If not, remove the plug and make sure that it has not picked up
any debris in the threads. If so, clear it out and try again. Once you
have all of the plugs started, use the 5/8" socket to tighten them just
1/8 turn past their stopping point. Do not over tighten as this is the
leading cause for plug-blowout with this engine series.
With all of the spark plugs back in, you can then proceed to
replace the coil/plug connectors. Replace the 7mm bolts for each coil
and tighten them snugly but do not over tighten. With the bolts tight,
the coil/plug connector should still rotate slightly. Reconnect the
electrical connectors for each coil by gently pushing them in place
until they click. They are indexed and will fit only in one direction. Reconnect
the air hose to the throttle body and any vacuum lines that were
removed. Replace the plastic engine cover and fasten it in place. That's
it, your done.
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4 plugs for a 4 cylinder, 6 plugs for a 6 cylinder and 8 for an 8 cylinder --none for a diesel
pull the coil / lead of each plug ( one at a time ) unscrew the plug using the appropriate tool and replace
when you have to ask these questions it will be cheaper and quicker to get them changed professionally ( plugs cost from $8.00 each for the cheapest to $25.00 each for top quality lines )
AS efi plugs seldom need changing but you have a problem like a misfire, run the fault codes first and have the injectors checked
A Simple 5/8 deep socket( get a spark plug socket they work nicer) and get some extensions and a ratchet and some swivels. I like to use 3/8 size tools. Once in a while a 1/2 tools may be nice if a plug is not coming out. Next soak the plugs in the engine with some penetrating oil if they are giving you a hard time. dont use alot, just 2 seconds of spraying. Allow engine to cool off to air temp. This will allow thing to not burn you or for you to damage the soft threads in the aluminum head.
Changing plugs have not changed much on these vehicles than vehicles in the past. Just remove the spark plug boots carefully. Now you can remove each spark plug. Use the extensions and swivels in many combinations if one is not working easy enough. Always make sure you know what gap these plugs need to be and set them. Always use an Anti-seize lubricant on the threads of the spark plugs. This will prevent them from under torquing and getting stuck in the future. Put preferably new spark plug wires back on and use Dielectric grease to prevent the boots from sticking to the spark plugs and from moisture getting in between them.
The first 30 seconds or so of running may be rough if you decide to use penetrating oil to loosen the spark plugs. This is why you should us as little as needed. More oil makes for longer crap running time. Just let the engine idle on its own and clear it out on its own. Dont rev the engine or force anything until it warms up to normal operating temps. Cold engines and revving is not good for internal parts.
IIRC these are a coil over design. meaning the coil is over the plug. the coil should have one 8mm bolt holding it on the lower intake manifold. remove the coild to get to the spark plugs. look by the fuel injectors, coil should be just next to it or very close. coil usually says motorcraft on it and circle in design.
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