strick92

I'm getting misfires on 1,2, and 3 while under load on my 2004 F150 5.4L. 2,000 RPMs or greater. The check engine light will start flashing and there's a ringing/rattling sound, it's jerking,
and I lose all power until I let it shift up. I get more misfires on 1 and 3 than I get on 2. It's not misfiring when idling.

I've replaced all spark plugs and coil boots, and tested all the coils by moving them around to see if the misfire moves. No luck.
I just noticed the EGR Solenoid vacuum hose is collapsed. Can this cause the misfires?
What should I be checking next?
I'm also getting a system lean code.

Thanks

laterongc

Suggest posting more specific info:

? mileage on truck, and how long was it running properly before this started?


? what was last thing(s) done before symptoms and/or egr hose collapse occurred?

? what model plugs and where did you get them?

? what are exact code #s?

strick92

160,000 miles
its my uncles old truck. He drives it around his farm. He doesn’t get it over 2,000 rpm’s so there’s no telling how long this has been going on.
codes are p0300 p0301 p0302 p0303 p0174

laterongc

strick92

I bought the oem motorcraft plugs from rockauto.

needsmoarturbo

Is this a 04-08 style truck or a heritage model which looks like (is) a 2003?
I ask because the 04-08 doesn't have an egr.
either way if you replaced the plugs already then youve either got water/coolant in the spark plug wells, or you have a compression problem, or a fuel injector problem on those cylinders.

strick92

It’s not a heritage style.

needsmoarturbo

Buy or rent a noid light or use a test light to confirm that the injectors for those cylinders are firing.
if the injectors check out ok then do a compression check on those cylinders.

manicmechanic007

If the noid light blinks like it should, replace the 3 injectors
Use Motorcraft injectors

strick92

It only misfires when under load at 2000 to 3000 RPM. It's not misfiring at idle. Even if you have it in park and rev the engine, it only does it while driving.