personneford

I have a 2004 stx (v6),and im having trouble with engine when it gets cool or cold outside. My truck will start great, but after a few minutes warming up, it will start to run rough, and the only way it gets better is once i start actually driving it down the road, and after that,it runs great. I had the intake manifold gasket changed 2yrs ago, for it had leaks with the stock gasket that ford uses, so that corrected that problem. I also changed plugs, and put in new maf sensor. Im still getting the check engine light on, and its still rough when temp outside gets below 70 degrees. Ive also checked for all poss vacuum leaks, but cant find any at this time. When they pull the codes, it saying running too lean..Is there anything else i should be looking for? Sometimes the trk will stall when backing out of the driveway, but again, once i start driving down the street for a minute, it runs fine...

adamrcannon

Have you checked the fuel filter? F-150's run lean naturally, might not even hurt to run 89 and see if that helps.

Just a couple ideas that you didn't already cover.