05 fx4 5.4l ignition problem
 

Hey all just bought this o5 went to go home from work and the truck would not idle right when came to a stop. Then on take off felt like it was not running on all cylinders. I took it back to the dealer and they said that it was mabey a spark plug prob or a wire. I still have'nt got it back yet anyone eles have this problem?:smoke:

Sounds like it could be the plugs or wires. That is the first thing I would check. After that, it may be a fuel pump or line issue. Has similar happen on a car I had. New plugs and wires fixed the idle and the smooth taking off and driving.

no plug wires on this truck!

did the CEL flash? if not prolly not a plug/COP issue.

Need to ask projectsho if the 05 has an IAC if it does might be the culprit.

Could also be a dirty maf,
vac leak
cam phaser (if equiped)

do a search on "rough idle"

sounds like the dealer you brought it back to wasn't a Ford dealer

hey your right
 

I didnt buy from a ford dealer but that is were the dealer worranty is from so I had to take it there they also said something about the o2 sencer. thx:)

I have the same truck as you (F150 fx4 2005) and I had a similar issue today. I was driving down the road and the little orange "wrench" lit up on the dashboard and my truck would not accelerate. I was only a block from a family members house so i pulled in the driveway and shut down the engine. Restarted and everything was back to normal. Drove an hour and a half back home. Don't know what caused that!!!!

An engine misfire. Get your codes read ASAP.


Yes, the 05 still uses an IAC valve. however, when it sticks or otherwise fails, the symptom is usually idle speed problems or stalling/starting problems, not an apparent misfire.

O2 sensors will not cause misfires, either. Misfires are most commonly caused by plugs, COPS, injectors, or other base engine problems.

Your vehicle needs to be checked by a technician that actually understands it. Sounds like this is missing at the "dealership" you purchased it from. Most likely, they don't have someone who is experienced or trained on Ford's EEC system and how it controls the engine.

Try to induce the failure condition, then try to force a CEL. Once the CEL has been lit, get your codes read.

Steve

5.4 3Vs don't use IAC valves, they're all drive by wire, idle is controlled by the electronic stepper motor on the throttle body.

Being that it's a 2005 engine, I'd suspect stuck/sticking injectors for a misfire before anything in the ignition system.

Hey
 

hey calhoudeputy the truck is in the shop still wont get it back until monday so i will right back when they tell me what it actually was. Do you have a problem with vibrations around 80to100 km or 50to 70 mph?

Got it back now!!
 

Hey all well I got it back and it turned out that a injecter stuck open and fowaled the plug. So a new injector and new plugs and its all good and all under warrenty.:banana:

sorry i didn't get back to you sooner. No I havent' noticed any vibration and the truck has run with absolutely no problems since it happened that one time. Hope it doesn't happen again!