Modular / Lightning guys?

[5.0calypso93lx]

I drive my 00' L daily and most of the time it's highway driving with the cruise set between 65 or 70. I was driving home last night from dinner and decided to get off on a backroad and mash the gas since I hadn't done it in forever.

That's when I noticed a missfire / breaking up. It didn't do it throughout the entire pull, but I could feel and hear a very noticeable breaking up that would come and go throughout the pull to 5k. I was pretty baffled since I'd never felt it before and the truck still drove perfectly fine at part throttle. The temperature has dropped big time here recently (down in the 40's in the morning when I'm leaving for work), so I thought that may be something to do with it.

This morning on the way to work I waited till the truck got all the way up to operating temperature, mashed the throttle again, and got the same exact result.

It's just strange because it pulls awesome for a second, then starts cutting out one second, and then clears up, but not in any specific pattern. I don't notice any difference in idle or part throttle driveability, it only happens at WOT. I was going to replace the plugs, but now that I'm thinking about it I can't imagine one going bad this soon. I was also going to starting unplugging coilpacks until I didn't notice a change in idle but the truck idles fine. I guess I could still try since I may just not hear it at idle, but if it's doing it at idle it is VERY mild. I don't feel a miss at idle either.

Any ideas? Truck is BONE stock save for a JDM Silver Bullet catback. Truck only has 36k miles.

[JIMS SVT]

Id check around the spark plug boot for water/coolant. Ive heard of 2v's having this same problem.

[2Kblacksleeper]

Make sure the spark plugs are not loose either. This was a issues on pre 03 trucks.
Also look for oil in the intake getting sucked back in on vacuum after boost.

I remember some of the little issues these trucks had since I had a 2000 but I dont remember them all.

John

[Blackout]

Id check around the spark plug boot for water/coolant. Ive heard of 2v's having this same problem.

Yeah if water gets down in the holes where the plugs are, it will definately act stupid.

When is the last time that you have done a tune up? Might be time for new plugs...

[Dirtyd0g]

Have you checked fuel pressure? Might have a clogged filter or pump screen. Coil's breaking down or something along those lines is the most likely.
Alan

[bobtsgt]

doing some basic data logs will also help point you in the right direction as well. If I have some time next week I can bring down my laptop and Xcal and we can do some runs

[orangeconv]

Regap the plugs, they could be blowing out

[cobraman302]

Weak coil pack possibly? Those truck are NOTORIOUS for coil pacs going bad. Mine had 3 go bad in a year and all had different symptoms.

[5.0calypso93lx]

Thanks guys, I started poking around a bit and looks like it's going to be fun to just change the plugs out. The coilpacks are wedged up underneath the fuel rail pretty good. As far as I know, they are the original plugs.

Bob, if you get time that would be great :bigthumb

[IWRBB]

The plugs look way worse to change than they really are. Take about an hour and pull all the air filter/intake piping, move the PCV lines out of the way and you'll have pretty good access. You can rotate the fuel injectors to get the electrical plug/harness out of the way of the coil bolts.

[smytty]

Someone mentioned the Fuel filter.. I had issues with mine at onetime.. Its a known issue that they get gunked up fast...

[SCHMUCKINGHAM]

Melted a plug strap, very common on Lightnings.


You can do everything with the fuel rails on but I strongly suggest taking the blower off to properly torque the plugs down. Only having the threads in contact really requires proper torque. Also, while your in there, clean the after cooler :)

[93hulk]

Mine was doing the same thing James. It was my plugs. They're Not that bad to change and the coil packs do come out from underneath the fuel rails pretty easy. I do recommend to run out to sears and pick up a 1/4 inch drive 7mm swivel socket. it will make getting the drivers side coil pack bolts out allot easier. Be Sure to put dielectric grease in the coil packs cause the passenger side back coils are notorious for getting water into the spark plug hole. Trust me I just did this this past weekend and cleaned my IC and stripped the rotors. Call me if you have any questions.

[thrillrr]

I have a 99 Lightning with 40000 miles on it . I have replaced 3 coil packs on it... It's usually one of the back two passenger side packs....Get you a 7mm swivel, like has been said ...makes a world of difference.
I also made up a tool just to change the plugs.. I used the craftsman 3 piece ext. set, 2 swivels and a sparkplug socket,and tacked everything together.

[2-8-1]

Thrillrr knows his stuff. I can also vouch for the rear passenger COPs. A lot of F150's burn through those two COPs for some reason. I assume heat soak or dampness. I also had issues with dampness on those same COPs on my 2V Mustang, however once I dried them off they were fine.

[pegasus]

it would be worth changing the fuel filter wile your doing the plugs

[mustang8998]

A lot of F150's burn through those two COPs for some reason.

Condensation, from A/C.

[2-8-1]

Condensation, from A/C.

So, dampness. I guess that is where the dampness in the GT's comes from as well.

[5.0calypso93lx]

I wasn't ever able to get the truck to replicate the problem until yesterday when it rained. I definitely think it is a moisture issue...