My wife's 98 Expy EB 5.4 4x4 with 187,000 miles normally runs really good. In the last month or so when it's been cold over night it will start with a miss and runs with that miss until it warms up. Then runs great after that. This is intermittent, it does not do it everytime it's cold. I am not very familiar with this motor and all the sensors and stuff. Don't normally have to do to much to it. So any help or suggestions would be appreciated.

 

When was the last time you changed spark plugs?
Poorly gapped, weak/old plugs can result in a poor spark and more noticeable when first starting and cold. After the combustion chambers and engine warm, the plugs more easily complete the combustion process at normal operating temps.

 

I am thinking they are around 55,000 miles old. Probably time for a tune up I guess. Would have never thought spark plugs that's for sure.

 

I had a similar experience and it turned out to be the original spark plugs were still in there with 140K miles on them and gaps twice what they should've been. New plugs and it's started perfect ever since.

 

Wife is leaving for out of town on Saturday. I guess that will be a good time to hit some of the maintenance stuff up. Got to start pricing things out.

 

If you are pricing it out for someone else to do, don't be shocked by the 200-250 dollar labor charge.
If you're doing it yourself, you will need some big time patience, bungee cords to hold hoses and lines out of the way, duct tape to hold sockets and extensions together, a variety of extension sizes, dielectric grease for COP's, anti seize for plug threads, maybe new COP boots if cracked, and great plugs as you don't want to have to do this again for 100k. A torque wrench as you don't want to over tighten, etc. lots of threads here on this process.
Good luck.

 

I appreciate the luck. I have done the plugs before. Driverside not to bad. Passenger side sucks BIG TIME!!! All that rear a/c crap makes it very difficult. I will be doing all the work myself. Can't afford to take it anywhere.

 

Took me 2 hours honestly... Just did this on my 03 but same motor for all intents and purposes. Make sure you have OEM Ford COPs in there, if not that could be part of your problem. Non Ford COPs burn out quicker, don't burn as hot and are just not reliable. I found a non Ford COP in mine and instead of paying $45 for a new coil I just got three used good ones from ebay for $17 shipped and rebuilt a set of 8.

That is another thing, get yourself a COP rebuild kit from Rockauto or Amazon, it'll come out to about $30. You are replacing the coil springs and boots which are the parts that usually cause the COP to fail, not the electronic part.

Finally, yes you will need dialectric grease, anti seize, an array of sockets/extensions/swivels and a torque wrench. Yes a torque wrench. These heads are aluminum, have 4 threads for the spark plugs and if you think that going even 1/8 turn past hand tight is ok on the spark plugs you're dead wrong. They are so easy to blow out it isn't even funny. If you do not have a torque wrench, you can get a cheapie one from Harbor Freight for about $20. They aren't the best but they will get the job done on stuff like this. Torque value with anti seize on the plugs is 12-15ft lbs. I just set it to 15 and go.

Now, the driver's side plugs are easy like you said, the passenger's side ones... also not bad honestly. Get a cheap magnetic spark plug socket, put a 3" extension on it and sit it on the rearmost spark plug (the hardest one). Then put your universal swivel on that extension, then attach about 2ft worth of extensions to that and use one hand to stabilize it and the other hand to break it loose. Install is reverse but using the torque wrench but always always always get these plugs started by hand or you could cross thread one and then you are done. The rest of the passenger's side plugs are closer to you and get progressively easier as you work forward.

I honestly had a harder time with the stupid COP retainer bolts than the spark plugs themselves. The plugs you want are Autolite APP104s btw. Those are double platinum and have a 100k mile service life. Gap to .052 and go.

 

But the driver's side has the EGR tube and the brake booster in the way, making it kind of a toss up.

 

Thanks Scotty for the part number, gap spec and the torque spec. I appreciate that. Gonna look for a set of ford coil packs. I think I have a set of eBay cheapys in there right now. Will see if I can find a good deal on set of one ones.

 

Scotty,
Not sure if this is opinion or stated fact. If so, I'd really like to read that info.

Sometimes, I'd rather someone state that it's their opinion, if so, or attach the info to validate their statement.

I've used Accel aftermarket units and they've worked flawlessly.

Nothing wrong with spending the extra money for Motorcraft if it makes you feel comfortable. I do for my 6.0 filters...but many can save a buck or two, if the aftermarket product matches up.

 

Yeah testing.

Here is a testing sequence someone I'm friends with on one of the Mustang forums I belong to did:

From what I have heard and observed it is a crap shoot, with a 50/50 chance of long term success.

When creating my COPTesto-The-Destructor COP tester (see below) I asked people to send me bad COPs for in-depth testing. I received a bunch, including two sets of "eBay" specials each of which had one or more COPs fail in 20k miles or less as reported to me. Most of what I received were aftermarket COPs, Accel, MSD, Granatelli, etc.

Do you have a bad COP? In general if they work without problem they are not bad, or weak, as they are just high voltage transformers. Ford stated in a notice to dealers, asking for them to do better testing, that over 50% of the COPs replaced under warranty and returned to the factory had nothing wrong with them.

COPTesto (testing a WeaponX COP):



I call it "The Destructor" because firing a COP repeatedly in rapid sequence, and dumping 100% of its energy across a large gap, will cause it to overheat and burn out. The stock COPs can take 24+ such firings before burning out, most after market COPs are all done in 15 to 18 full dumps. In normal use a COP only discharges a small fraction of its full charge.

Some of the COPs I received:



In this photo is a set of Weapon X standard units with 5 burned out, a couple of burned out Accels, and front and center one of the "eBay" COPs.

Here is a video of a stock COP firing across a 16 mm air gap...

There are plenty of other documented tests if you search, this is just one example. Obviously this is a "torture test" and not normal conditions but it does prove the Motorcrafts are better. Will the Accels be fine? Probably but they might not last as long. The test above takes a very short time, stretch that out over 100k+ miles... you see where I am going. Again, its generally the boot or the spring causing problems, not the electronic portion so getting a set of used "checked good" OEMs from the evilbays or wherever and then just doing the boots/springs is fine as far as replacing them. At least IMO. YMMV.

You can get Motorcrafts new on Rockauto for about $300 plus shipping for the set if you need to buy a whole new set, or a set of 8 used good ones for $50 on ebay plus $30 for the new boots/springs. Or the Accels. I know everyone has a different budget. I got the used COPs to replace my ebay ones so...

 

I've driven 10s of thousands of miles on the eBay COPs without any issues. I know some will say they are inferior but let's be real here, no one is racing these trucks and 90% less than the dealer price is nothing to sneeze at.

 

I agree 100%, not knocking them. Just trying to figure out what's going on with the truck.

 

They may be OK, i mean they are not hard to change. I come from mustang land where we routinely spin to 6k+. Regardless, the OEMs are better but if you are on a budget the $100 sets of generics and autolites is tempting.