At 58,000 miles I developed a miss at 45 mph. Have had three (3) sets of plugs wires, transmission fluid changed, and recently the tensioners on the timing belts changed. I still have the miss. My truck is now at 75,000 miles. I am at my wits end. Anybody else had a similar problem??? Any technicians with an idea or two. I am working with a Ford dealership in Indianapolis. They are reasonably puzzled as well. Before replacing the tensioners the warmer and humid it got outside it seemed to be worse. Before having the truck in the shop the last time it would miss at all speeds and even at an idle. My most recent repair DID NOT solve my problem. Thanks in advance for any ideas. DaWG of Indpls...03-25-2001

 

If you have the dealership working for you ask them to swap out your computer, then test drive .

 

Longbow,

Thanks...That may be the next step. I took my truck back into the dealership yesterday and the computer stored a code P0301, which is a miss fire on cylinder #1 again. There was a hairline crack in the porcelain in the sparkplug. Runs great today. It is rainy and reasonably warm here. These are the conditions it ran its worst.

Have you had the same problem??

Thanks for responding...DaWG of Indpls...
03-29-2001

 

I had a similar problem. Mine was a simple fix. It seemed the spark plug on cylinder 8 was missing. After examination I noted that the plug was arching. After replacing the plugs with motorcraft replacements and new motorsport wires the problem was gone. Since I changed my own plugs let me tell you that it was really hard to tell if the wire boot was securely placed on the plug. I used some electronic grease don't no the proper name but by applying a little on the boot it slid right in.

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1997 4.6 xlt 5-speed.
System includes Clarion head unit, 2 12w6's, jl 6 1/2 components, Two alpines running the show.

 

Da WG
I have a similuar problem but not as noticable it is a slght miss on acceleration @ 45 and beyond.

Happy to see you have a resolve, I think with all the electronics etc on these engines I'm sure that the bulk of this type of problem lies between the computer and plugs .
Next time I take mine in (still under warn.) I 'll have the plugs checked out .

My ride 98 XLT SC 4.6l , 4x4 20,000 miles

 

Popeye

Thanks for responding.

The grease you are talking about is Dielectric grease. I used that product and it helped a little bit, but did not correct the problem. Of course if a plug was bad it was in your case the hardest one to get to.

How many miles have you driven on your repair? It seems the repairs I have had last about 250 miles and then it runs bad again.

DaWG of Indpls...03-29-2001

 

The Proper name is Dielectric grease it is also what Ford uses to lube the caliber slide rails during a brake service. It is a st for spark plug boots, otherwise a misfire is eminant. The hairline crack in the spark plug either occured during installation or the it was dropped in the parts department before it was installed. Glad u have it figured out!!!!

 

Superdave666

Only time will tell whether or not we have it figured out. With the tight quarters the technician has to work in, it does not surprise me that something like that could happen.

Thanks for responding...DaWG of Indpls