germanshepherd

Need help please. I spent hours searching and just not sure what to do. here is what I did have done to my 06. new plugs (motorcraft), COP's, cleaned throttle body/maf. new fuel and air filters. fresh oil. The truck idles ok for most part but still not 100% smooth. I also noticed now that after the plug change, when I give it heavy throttle, it will initially sound like it bogs down for a second before it revs up and accelerates. if I hit the pedal slowly but still pressing down it pulls and sounds strong but if I give it a heavier push, it makes that bogging down sound before engine picks up. RPMS seem ok when this happens though.

will resetting the PCM help with any of this? I did not recall it doing this prior to plug change. the idle is about the same as before the plug change. I read that many 5.4's have this initial hesitation with no known fixes for some people.
just not sure what all a PCM resent can fix, or even a reflash. thanks

germanshepherd

let me ask it this way, if I reset the PCM, will it hurt anything or make things worse or start throwing codes? maybe I need to accept the fact that this particular truck is just not going to idle as smooth as butter. I spent over a grand on it already trying to get a smoother idle. its annoying but not the worse idle either.

Newfiedan

I have a slight shudder at idle as well and like you I have spent a lot of time on it. Lol so far new headers (had 4 broken studs) new plugs, checked all my cops and put new plugs in. New phazers/ timing chain set and all new gaskets for the intake manifold and timing covers and valve covers. I gutted my 2 front cats due to one being burnt up and relocated my secondary o2 sensors to the rear cats. It's the best my truck has run so far but I still have the slight shudder. If you have the torque app check your fuel trims. My short terms match but my long term is slightly higher on bank 2. I am thinking I may have a crappy injector on that bank. But no loss of power when under load just that annoying idle shudder. I also cleaned my mad twice and the throttle body.
Resetting the ecm by unplugging it will reset the fuel tables and get it to relearn them but you may want to do the idle relearn procedure as well.

germanshepherd

thanks for the tips. I would have to have my mechanic do/check these additional things other than the resetting of PCM. I may just wait for now since I put so much into it already and money is getting tight. wondering if the idle issue is related to it doing that initial bogging down for a split second.

Newfiedan

Initial bogging may be from the foam gasket that sits on the face of the air filter tray. Remove it and check that gasket there is usually a moan associated with it but not necessarily. Use foam door gasket from any hardware store to repair that.

germanshepherd

thanks, did see that in other posts, mine was pretty much gone too and I replaced it with new foam but did not help but appreciate the tip.

germanshepherd

well I did notice today as far as the hesitation goes, it does it when overdrive, if I hit the overdrive button to turn it off, it does not do that initial hesitation thing. will do some searching..