jonboyb

My 2011 EB FX4 developed a slight miss/hesitation around 50k miles. 50-70 mph under any throttle you can feel it, but more pronounced the harder you hammer it. Not a condensation condition.....I know that one and this is FAR less violent and does it any time I want it to. This is just a subtle stumble....but it pretty much last as long as throttle is held consistent.

Anyways, when I started noticing it I immediately changed plugs with no change to this condition (low speed operation did improve though). Inspected coils and boots very closely, but nothing visually. Been driving now for 10k more miles after the new plugs with the miss and I make it do it all the time trying to throw a code, but my truck has never flashed a warning period. I thought eventually it would reach an adequate count and throw a CEL...but no luck. My idle has been smooth since the truck was new....but started to see a little wiggle now in the tach at redlights.

The thought of taking it to a dealer makes me sick even thinking about it....I haven't had any luck with a dealer in years across several makes and models. I've called about bringing it in for diagnostics, but there's $100 off the bat and if it shows anything.....they'll charge 10-fold for repairs anyway. They will NOT send a technician with a laptop to log the miss with me driving either. I'm seriously considering just buying a set of 6 coils and swapping....probably end up being cheaper than Ford diagnosing and replacing 1 bad one (if they even find a problem). They wanted $300 to change the plugs and I bet money they'd force me to let them change them again no matter what the outcome.

I may waste $360 bucks for the coils.....but it's tempting. Has anyone seen a thread where someone has successfully found a bad coil through manually testing impedance or other values? Man I miss working on old cars

jonboyb

I could buy a single coil and swap out one at a time too....but that sure sounds like alot of effort

ecoboost clark

I'm with you, Dealer violated me a couple months ago.

venatic

I had a bad coil on mine, but it also set the check engine light on it. Ran really bad and I took it to the dealer the next day. Turned out to be a coil that shorted out and they replaced it. I had an extended warranty on it, so I was only out $100.

maplelakeduckslayer

Coils did nothing for me. New in tank fuel pump did but that only lasted 4 months. Back to not running properly. Got code for o2 sensor, replacing this weekend. If that doesn't fix it on to another fuel pump. I'd look at your rear fuel pressure...I think fuel pumps are going to become more of an issue as more trucks get miles...I'm at 120k miles

PSI-FX4

How tough is it to change the fuel pump on these trucks?

maplelakeduckslayer

Not super hard. I had trouble getting the rubber fill hose off the fill neck, so I fished the whole thing down with the tank. The difficult part was fishing it back up because it needs to be twisted to go in and you have to have the twist right or the rubber will be kinked. If you can get the rubber hose off the filler neck than no problem at all.

KJ Smith

Did you drop the tank?


Last truck I did we removed the bed.

Fordman1979!

My Eco has 35,000 on it and I had a coil go bad. At first I thought it was a cylinder misfiring because when I punched it the truck would surge and hesitated to get going. I really couldn't get the power I wanted out of it. I took it to the dealership and they advised it was a bad coil. Lucky for me my truck was still under warranty and they replaced it for free.

maplelakeduckslayer

Yeah I dropped the tank. I should have cleaned the tank out though now that it appears it may have gone out again. Taking the bed off is maybe an easier option if you have some friends around, just didn't want to bother anybody to help me.