Started having issues with this yesterday afternoon. Riding down the road and it's like the truck will start bucking or hanging up. Kinda hard to describe. I don't have much experience but I think it may be misfiring. I have about 220000 miles and haven't had a problem like this before. Haven't seen a check engine light or anything like that yet. It's a 2001 Lariat with 5.4 V8. Thanks for any help.

 

By the way. I don't know if this has anything to do with it but on cold mornings the truck will idle rough for a while. It will sound like it is revving itself.

 

I have the same truck, trim, engine, year and mileage. Lol. Sounds like a misfire to me. Most likely a bad coil pack. I have had 3 go on me now. The check engine light took a while to come one but eventually did.

If it is a coil pack, the advise I got on here was to buy either Motorcraft or Visteon brand. Motorcrafts were a lot more expensive. I found Visteon's on eBay for about $35 or so shipped.

 

The revving and the bucking are two separate issues but they compliment each other. If that makes sense.

The bucking is most likely a coil or two going bad. Even if the cel is not on you can get it scanned and come up with a bad coil number.

For the revving, I would check all your vacuum lines, especially the pcv valve and where it connects to the rear of the engine. That sleeve has been known to go bad.

 

I have the same year truck, engine and mileage.

I started to experience coil failures right at about 200k. It takes a long time before the check engine light goes on. This really surprises me considering how violent the misfire is. Once the check engine light goes on, it will tell you exactly which cylinder is misfiring. Change the plug and coil for that cylinder. I have had three go out in the last 18k miles.

Unfortunately I used cheap 3rd party coils and they go out within 2-6 months.

I just ordered up 8 motorcraft coils from rock auto and I am going to replace all of them so I don't have to deal with it. It isn't cheap at $41.79 per coil, but I am planning on keeping my truck for a long time, even if I have to put a rebuilt engine or tranny in it, so it is worth it to me.

If you are planning on keeping your truck for a long time still, I would go motorcraft, if you think you are going to be selling it and getting something newer, 3rd party is fine.

 

Well I'm only 17 so an upgrade really isn't an option. And plus I really like my truck. I just put a light bar and new fog lights in to make it look a little better. My dad will help me out probably and I would like to keep my truck running good. How hard of an install is it?

 

I have 260K on my '02... I've changed out more bad coils than I care to remember. Most of them are cake.... #7 is a mother.

 

Ended up being a coil pack and 2 plugs. Anybody know about the revving when it's cold?

 

7 is a mother!! Fuel line runs right over top of it!! 8 is pretty bad too. But 1-4 is cake and 5-6 aren't too terrible. Mine started crapping out at 150k replaced the plugs at 140k looks like for the first time. I bought them by the box of 8.

 

Only when it's cold? No engine codes? Or cel?
Do you have an ultra gauge? Their like 65 dollars if you don't have one. Best purchase I made for this beast.