I have a 2002 F-150 w/ 5.4 Lariat. It has been sitting in my driveway for the last year and only driven around the block about once or twice a month. A few months ago, when I took it around, it started running very rough and the service light came on. I parked it and have not moved it since.

Now, I need to get it running again. It had a 1/4 tank of gas in it so I filled it up and put in a can of sea-foam stabilizer and cleaner. I plugged in an obdii to it and I got back a code for P0174 for fuel to lean. I reset the code and cleared the computer. I then drove it for a couple miles trying to get the light to come back on.

In the past, I have always had bad problems with the coil packs and that is exactly what this feels like, but without a code, it is difficult to tell. It feels like it is missing on a single cylinder.

I also have a seized fan clutch that I am about to replace, but I don't think that would have anything to do with the rough engine.

Any suggestions. I am probably going to drive it a little to see if anything clears up with some fresh gas in it.

Thank you.

 

Also getting a P3400 Cylinder deactivation code now.

P0174 - Powertrain
System to lean(Bank 20

P3400 - Powertrain
Cylinder Deactivation system (Bank 1)

After driving around for about 15 or 20 miles, the codes have changed.

Current Fault:
P0174 - Powertrain
System to lean(Bank 20

Pending Faults:
P0300 - Powertrain
Random/Multiple Cylinder Misfire Detected

P0306 - Powertrain
Cylinder 6 Misfire detected

P0307 - Powertrain
Cylinder 7 Misfire detected

P0316 - Powertrain

 

I would certainly look at the coils - especially 6 and 7. Change the fuel filter. Check for vacuum leaks, especially the PCV elbow behind the intake and the HVAC lines behind the battery.

 

I pulled the coils and plugs from 6 and 7. They were both full of rusty water. I blew it out with an airhose and pulled the plugs. I cleaned the coil packs up and removed all the rust, then regreased them. I also replaced the fan clutch.

It is certainly running much better, but it is still not right. It feels like it is only running at about 80% power and it will surge to 100% frequently. After turning it off and on a few times, I am now getting a P0351 code (Ignition coil "A" Circuit condition, PCM did not receive a valid IDM signal from the ignition module while the engine is running).

I am going to change the fuel filter after I run through this tank of gas. Vacuum is running at around 25.

 

ok, tried to edit my last post, but it kept crashing my browser.

I reseated the plug going to the #1 coil pack and it did improve even further. It feels like I have about 95% power back with just a slight miss now, however after driving it around the block, it seemed to be getting worse and dropping back down slightly with the miss becoming more noticable as I went.

I will try to work on it some more tomorrow.

 

I would change the plugs and all the coils. Use Motorcraft plugs and here's a set of OEM quality coils:

http://www.ebay.com/itm/8-PCS-BRAND-NEW-IGNITION-COIL-DG508-VISTEON-MADE-REF-60-1000-/281096663035?pt=Motors_Car_Truck_Parts_Accessories&hash=item4172aaaffb&vxp=mtr
Don't forget to use dielectric grease in the coil boots, and I'd clean out all the coil harness plugs with electrical contact cleaner.

 

I don't know if this will apply to your situation. I have a '94 T'bird with the 4.6 in it. I usually let it set during the winter. I start it up every month and maybe drive it for a bit if the weather is nice. Since I've got the truck I rarely drive it (which is going to change her shortly). Usually in the spring I get the same problem. For me, It's usually in the EGR system, the valve gets stuck or somehow gets plugged up. I haven't done seafoam, although all the guys in my T'bird club sware by it. I usually spray a crap load of T-body cleaner down the EGR tube and let it set for a few, then start her up and run her around. I know the newer 5.4's are different, but thought I would suggest it any way.......

 

If the EGR passages are plugged, you should get a P0401 code (EGR insufficient flow), and that won't make it run rough. It will just cause lousy gas mileage. However, if the EGR valve sticks open, then it will idle rough and maybe even stall. I would think that would give you a P0402 (EGR excessive flow).

 

The reason the truck has been sitting for a year is because I had a company vehicle that I drove before. I lost that job last week and, while I am hoping to find something soon, money is going to be tight until I do.

I can certainly replace the coil packs and spark plugs if it is necessary, but I need to make sure 100% before I do.

I can pull the coil packs and check the resistance on them. If they read as good, would it still be advisable to replace them?

 

Resistance checks won't tell you anything unless they are dead short or dead open.

If nothing else, pull #1 again and clean it up.

 

Ok. Thank you. I will start with that.

I found the Accel plugs that can be shipped and arrive by tomorrow. Are those decent, or should I stick with the oem?

 

Send them back, use only Motorcraft plugs. If you meant cops, get the ones I linked.

 

Well, the fact that the plug wells 6&7 had water in them is the clue. Since that won't happen unless someone hosed the engine or left the hood up in the rain for a long period of time. It was indeed water not coolant correct?

Regardless, the coils are compromised, -shorted, but not completely. Not yet anyway, but are damaged enough to DEFINITELY warrant a change out. Otherwise you'll end up pulling your hair out because intermittent problems will continue to occur, with you , - spending much of your time under the hood, puzzled, confused.

You don't want to miss that interview or orientation do you?

Well, you can avoid all that by taking/doing what glc posted exactly. That is the smartest thing to do, for more reasons that I feel like mentioning right now, is just that.

Grab those Visteons, he only has 4 sets left and they come and go. At that price, -well, your just lucky you can get that kind of quality for a fraction of what they list for at the dealer.

Use Motorcraft plugs and NOTHING else. These engines can be real finicky and usually are when it comes to ignition components.

There's only two other brands of plugs you can use for that modular. -

Denso's or NGK's. Since they are the only manufacturers that offer a quality fine wire iridium plug, - one that can handle that engines heat range.

Do that, - it will feel like a new truck once completed. With half cooked (weak) ignition system, -these trucks run like heavy slugs and suck a lot of fuel. Do all cylinders the same,- and all at once. Ignition integrity is important and you'll have that as long as you listen to what's being said.

Once a coil gets wet, -sure , you may be able to dry it out and it may fire for awhile longer... - Thing is, it's been shorted/hurt and if it fires right at all, it won't do so for much longer. Best thing to do is what's posted,- given your descriptions.

 

Thanks for the advice from both of you. I ordered the Visteons last night. They will be here on Saturday. I can pick up the plugs locally.

I am having to drive around a little. When it is cold, it seems to run ok, but as soon as it starts to warm up, it starts missing pretty bad. It will be nice to have it running well again.

 

Glad you listened to these 2 guys.. They know a thing or two when it comes to these trucks... Id be willing to bet that it will fix your problem..