04 5.4L FX4 113K

When driving in overdrive, around 55 - 75 mph (1800 - 2200 rpm) my truck will start hesitating under slight acceleration. If I accelerate hard (gear change) it does not do it.

When it starts stuttering, if I don't let off the gas the engine light will start blinking and the truck will stutter badly for about 20 seconds. Then the engine light will go on solid, the truck will smooth out and then the engine light goes off.

It seems to do it worse on warmer days or after longer periods of driving. On a real cold morning (in the 20's) it rarely does this.

Any thoughts?

 

Sounds like a random missfire, it's a plug, coil pack or both did you pull any codes yet?

 

Try to clean....
The TB
MAF
Change fuel filter.....

If those don't help start to look at changing the spark plugs and or coil packs....

 

If you have 113k on the original spark plugs, that's most likely the problem.

 

I've got the same problem. Already changed the fuel filter, cleaned the MAF and throttle body. at 150k miles now, did plugs at 110k.

 

+2... already had 2coils replaced under warranty early on... out of warranty now.. .120k... plugs were replaced at 70k i think..... but mine is on excel...i'll give it gas, and it will backfire.. or back pressure out the tailpipe... but i've read its due to back pressure in the exhaust... maybe not enough~?

 

COPS, boots, connector springs.....they all wear out....
Look up global on eBay and look for DG511 get a set for the v10 and you'll have a couple of extras...