Started having this problem last weekend. Have
checked the fuel pressure (40-50), plugs, boost,
etc. on my '02 with 11,000 miles. It's not setting
any codes that would indicate the coil packs are
failing, but I can't think of anything else that would
cause this. Chip is seated well, checked the vacuum
lines, etc. Ran two cans of HEAT through and two
tanks of gas, because the Ford Dealer thought that
was the problem. It's back there now for the third
trip in.

If I punch it from a roll, it breaks up immediately, and
if I am stopped and launch, it sometimes breaks up
immediately and sometimes not. (I hate intermittant
problems!) Then it breaks up again at about 5200 rpm
just before all shifts.

Any ideas?

TIA,

Cliff

MY MODS:

JDM stage II + NGK TR6's

 

Fuel filter? I change mine every 12k miles.

 

Like ED said. It's probably the fuel filter. Check that first. I have under 13,000 on mine and havn't had any problems. Let us know what happens.
J-mart

 

I recommended that to the Ford Service Advisor, and he
said that it wasn't due until 15 K service. Wonder if they
can test it or something? Can't be too expensive, can it?

 

23k miles and I am on my 4th fuel filter. If that doesn't do it try and duplicate the problem with the chip out.

 

Well, with the chip out, it really dies 'cause of the 4 #
pulley boosting I think ... least that was what happened
when I tried that the other night ... Couldn't get on it
at all ...

 

In a word "Cats" go fell the exhaust tips and see if there is any flow, lots of flow...... Sounds just like mine when the cats fell apart and plugged.

 

I don't know if there is one but there should be some type of crank trigger to send signal to each coil for spark. Maybe it is not picking up signal at higher rpm's, or what about the MAF or TPS
could go intermitten and not set a hard code

Hope you find it
Just a guess on my part
Slick

 

Well, replaced the Fuel Filter ($49.00) and it's still there
so I guess it's strip it back to stock so I can have them diagnose
the problem. He ran the sensor stuff on it and even through the
breakup didn't see anything dropping spark or other stuff ... so ,..
It's gonna be a LONG night!!!

 

What are the TR6s gapped at? Did you change them? Are the coil pack connectors and the fuel injector connectors pushed in all the way?

Dan

 

Pull and check your plugs first. All of them.

 

Well, the latest is that the pulley will NOT come off ...

Interchangeable? I seriously doubt if anyone can ever
get these things off after they have been on for a while.

Next step is a Sawzall ... Cause a 6 point socket and a
three foot cheater and a 16 inch pipe wrench didn't touch it !!!
The Pulley now rotates on th eshaft rather freely, but the
bolt still isn't loose ...

I can see how Doug's got messed up at the dealer ... dayum
this is tough stuff ...

Anyone else have trouble getting the JDM pulley off ?

Cliff

 

They didn't see anything wrong with mine either. When I went to pick up the truck from the dealer, I floored it as soon as I got to the road. It did it again (mis-fired), so I turned around and took the tech with me for a ride. Sure enough he knew exactly what it was (coilpacks), took it right back into the shop and gave it back to me a 1/2 hour later with the problem fixed. That's what I call good service!

 

Of course you remember it is reverse threaded... Get the cheater on it and put some pressure on it then have someone tap the shaft to get it to break loose... The 450 ftlbs gets it pretty tight
Good Luck
Doug

 

A little birdy told me that it sounds like you have a piece of junk caught on your MAF hotwire.