05' F150 5.4

Step on gas and truck has no power, runs extremely rough and the check engine light blinks for about a minute?
Anyone seen this problem before?

 

Generally when the CEL flashes its due to a misfire/s or a rich condition that exists that can/will damage the catalytic converters. Basically unburnt or unmetered fuel entering the exhaust causing high temps and can relatively quickly destroy the Cats.
The reason for it running extremely poor could be ignition items related, fuel drop ( injectors etc) When did the rough condition start?, did it come on quickly or more over time? Mileage on the truck?, any/all regular service or repairs done, anything lately prior to the drivability issues? If you can have someone read any stored trouble codes it would be a help in a direction to go.

 

05 F150 137,000
Bought truck with 132k. As far as regularly serviced not sure. Had a couple codes pop up about 500mi ago. They have come and gone but still truck doesn't run how it did when I got it. Codes were po307 and po174 which was misfire cy 7 and lean system bank 2. I took coil from cy 7 and swapped with coil from cy 1 cleared codes. Truck ran perfect for about 2 days then ran poorly and po307 code came back but po174 did not.
Now truck sometimes runs good and sometimes poor but if I really mash the gas cel will flash.
Frustrating!

 

Being it seems more intermittent, would seem to rule out ignition, but that said,, with that high of mileage and no service history, if the plugs are OE they'd be well beyond the change interval. Ignition breakdown/misfire most times is felt under steeper throttle angles,, sometimes idle if bad enough, or anything in between, but generally doesn't go away for days at a time. Base engine, comp etc generally won't be intermittent either. If an injector hung, or is failing it could be intermittent and not only cause the misfire, but allow unburnt or unmetered fuel down into the cats. Either way, continuing to drive it with a flashing CEL is gambling for 'very' costly Cat repairs...Might have a look at the plugs if unknown, (comp never hurts either to gauge base health) check injector connector/s and if the misfire continues, possible replace or relocate the injector for that cylinder. Cats assy are very expensive for that truck..

 

Is there any way to check if plugs are OE without removing? Read about how they can be problematic. Do have an idea why when I swapped out coils truck ran great then back to crappy in a couple days.? It just seems if it were plugs swapping coils wouldn't change anything. Heck IDK. I appreciate your help and input.

 

Plugs would be just something that would be way overdue if OE and at its current mileage.

You could pull one, generally one of the forward is easier, and check to see what brand was installed and its condition. If they've been run close to 140k, the electrode may indicate some-excessive burn back or out of spec gap spacing and can at times indicate how long they've been run. Or, if they could be of any suspicion due to gaps or any collected deposits on the plug face. 'If' it is an injector/s,, removing the plug/s will help pinpoint cylinders running rich or being over fueled. Other than the PO174, without multiple or random misfire DTCs kind of suspect as to other contributing components.

Like MAF,, it would generally affect the cylinders performance globally, and not just individuals. Same goes for vacuum leaks, EGR, leaking fuel regulator, EVAP etc, tend to affect overall cylinders performance and most often aren't intermittents.
Cat restrictions,, sometimes but again not intermittent.

You'd have to consider what would cause an intermittent very rough condition and no, in most cases it's not plugs. A more consistent breakdown or misfire that most times can be reproduced under varying throttle angles or loads/speeds is more likely to be due to ignition related items. But with the plugs, I usually like to know 'what's it's not' before moving forward. More so if there's no service history. The flashing CEL generally means too much unspent fuel is being dumped into the Cats. Ignition misfires can produce the condition, as well as injector issues, harness connectors (injector and COP connectors are in close proximity) or engine/fuel management components.
If your getting a consistent single cylinder position misfire, checking that plug during an 'event' may point to an injector failing or hanging open allowing an unmetered fuel drop. Or,, not...

So,, question, when you say you 'step on the gas' and the truck has no power, is that just off of idle? or, at speed and the throttle is 'held down' to try and force power out of it?

 

Just a couple of simple maintenance items. Could be something simple like dirty fuel filter causing fuel starvation, bad/worm plugs requiring the COPS to work harder to fire, especially under load, dirty injectors (as mentioned).

 

Man I sure appreciate all the info!

To answer your question when I accelerate off idle truck has power usually when I'm going up a slight grade when rpm's are at about 1500 it seems like its choking.
Also from idle if I put the pedal to the floor is when it runs real rough/less power and the CEL will blink.

 

"I put the pedal to the floor is when it runs real rough/less power and the CEL will blink"

I know not the same animal, but my Son's 2000 Taurus w/3.0 DOHC w/COPS did the same thing. Ended up needing a fresh set of plugs all the way around. I also shortly later put a new set of COPS on it as the boots were pretty wooped.