My '02 4.6 is missing on acceleration. Runs smooth at speed, tho.
I checked the fuel press today and it is 32 psig when engine running.
Engine idles great.
Put my little WalMart code checker on it and sez...no codes. I don't have a check engine lite either.
This truck has about 160 K miles on it. It has been taken care of before I got it. Nary a bit of rust and paint is in great shape.
The Ford place I got it from says the plugs were just changed. I am fixing to start pulling them and have some new ones ordered.
My plan is to look at the plugs. If they are new, to replace anyway and then to go make a loan and buy the coils.......if the plugs are old and haven't been changed....just to go with new plugs.
I have read here that testing the coils is useless.
Any input on this approach to my miss problem ?
Thank You

 

Read your mode 06 data.
You may need an obd2 adapter and app that will show it
It will show misfires count that has occurred without throwing a code

Check PCv tube; as well for leaks
Blindly throwing parts at it is a last resort

 

Fuel pump is at the end of it's life.

Where does it miss exactly and under normal acceleration driving down the road, - just above idle or at 40mph plus?

 

Last year the '00 4.6 started missing under load, ran fine, idle fine, at steady steady speed no problem, no codes, long story short, one bad coil.
The freakin truck eats coils, only put about 200 miles on the truck after purchase and needed 2 coils at different intervals, so picked up 8 and changed them all.
What I did, a little archaic, I didn't have a reader for each individual cylinder when the second one went bad, so I disconnected each coil one at a time when out for a ride.
Although missing all the time as it was running on 7 cylinders, under load when it dropped to 6 cylinders a definite change was felt until I hit the coil that was a goner,
no change. As I started on the passenger side, it was number 4 cylinder, so didn't take long to find.
Just an FYI-Drove the truck 20+ miles when the first coil completely malfunctioned and probably 15 miles when when the second started missing
under load, and at no time did the CEL come on.

 

Back in 05 I had a coil go bad in the 98, - low grade misfire. It would miss right after shifting into OD. I was able to pinpoint the cylinder it was on from hitting the gas hard as soon as the CEL started blinking. The on board gave me the code...that doesn't happen to often as the misfire monitor needs such a high misfire count to end up on the KAM. Coils were crazy expensive back then, 90 plus for 1 at the dealer or 60 plus 3rd party if they carried them.

In 06, had another one go, this time I couldn't get the monitor to pick it up. Replaced all 8 for system integrity. Back then Visteon and Motorcraft were the same coils. Also the only two built to Ford spec. Got a deal on Visteons and haven't had a coil problem with that truck since.

You can't get Visteons anymore, but there is Denso now. Denso sort of slid into Visteons slot. Since Motorcarft and Denso are the same Ford spec coils today.

 

Good info on the coils (and the fuel pump info....will put that on the list for later)
My truck is missing at the 40 mph and up accel....I can't tell if missing any sooner.
The PVC hose is bran new as well as the PCV valve. Had to whittle the old hose off the manifold...ha
I got a flip phone and it is a real dummy phone....like it's owner...ha ha. Can't hook any diagnostical thingys to it.
I am keeping the truck and will replace all (plugs and coils) because I don't want any worn out stuff in there. I had just as soon replace it all while I am at it.
I ordered coils from Rock Auto....think $25 each...Denso. Glad I read this forum and know about them. Ordered the plugs (Motorcraft) off ebay...$32.04.....plugs are:AGSF32FM .
Will use the rubber hose trick I learned here when installing them......and install dry and to 28 FT/LBS
Thank you

 

Coils will fix that...since it's missing under load after 40.