Louisiana1

I want to start of first by saying I know there are topics on this however I could not find any that contain my specific circumstances. I have a 2001 f150 with a 4.6 v8 and it has 67k miles. I just made a 4 hour trip without any problems however when I drove it the next day I noticed that it was really having trouble accelerating. It would have really delayed acceleration and the engine would studder. I noticed this most during light acceleration at lower speeds and cruising around 40 mph. Didn't seem to feel it as much on the highway. Now all this would have me believe it is a simple misfire however my check engine light is not on. I do not have access to a scanner because I am at school but I just wanted to get an idea of what this could be. I thought it was very strange that I did not feel anything yesterday when driving for 4 hours but I felt it first thing today. Could this be spark plugs or coils? Also something else that is on my mind is this weekend I did the Gotts mod however I put it back to stock after one day because I was trying to avoid something like this! Could that have anything to do with it? Possibly a MAF issue, however would that cause a misfire?

M4gery4x4

its possible that it could be a bad coil especially if your stillin runnin the original ones, check engine light wont always come on right away either sometimes It takes a while or for the misfire to get worse before itl display. my buds expedition doesn't have a CE light but if ya scan it 2 codes come up. am sure theres other possibilities causin the shaking, dirty maf possibly, hopefully some others will reply shortly with some better tips

Louisiana1

Thanks for the advice. Unfortunately, about the only thing I can do myself is clean the MAF because I don't have my tools with me at school. I'll try to scan for a code tomorrow at autozone however that won't do me much good except for giving me the peace of mind of knowing what it is a preparing for the mechanic's bill.

Bronco302

Louisiana1: A code is definitely the place to start to point you in the right direction. If you can get access to a scan tool that has the ability to view miss-fire monitors or better yet a power balance feature it will quickly point you in the direction of what cylinder is miss-firing. Ignition related misfires typically can be replicated by putting the trans in gear and applying the brake and increasing the rpm, this will load up the engine and ignition related miss-fires will usually show up(view power balance or miss-fire monitors). It could be water getting past a coil boot shorting on the plug, bad coil or a worn spark plug. If the miss appears to be random I would check fuel pressure and visually inspect for a dirty maf sensor first. Multiple cylinder misses can also just be a set of worn plugs or plugged fuel filter, if you have never done the plugs or fuel filter it might be a cheap place to start.
Hope this helps....

M4gery4x4

if it is a bad coil its only about $40 for a new motorcraft one, only tool ya need is an 8mm socket for 1 bolt holdin the coil down, should only take about 5-10min tops to swap it out

jferg92

Where are you finding motorcraft for $50?

M4gery4x4

rockauto, $41 a pop for motorcraft coils

Louisiana1

Update: Took it to the shop and of course the mechanic didn't feel anything after he drove it. He said it is probably the coils however he would rather just replace the problem coil instead of replacing them all. So he told me to bring it back next time I feel something. Also said that it could be water getting under the coil boot? It is so strange that it has been so obvious the past few days and all of a sudden its gone. I still have a sneaking suspicion it has something to do with me messing around with the air intake...

wilson84

He doesn't.have cops he has two.coils.n the front go out side in the dark pull wires off.one by one with truck running c if it arcs if it doesn't it means a bad coil

Louisiana1

I was under the impression that I have 8 COPs. Just to clarify I've got a 2001 4.6L.