on my 2000 5.4l f150 when i start it cold or hot 75% of the time it start idling at like 1700 rpm(ish) and slowly goes down to about 600 rpms over about 10-20 seconds and it will also idle high when i put it into a different gear (automatic btw) just for a couple seconds just wondering if this is normal and if its happening to others...thxs

 

My 97 4.6 idles high when I start it then drops after a few seconds it also drops when I put it in gear

 

like if im ina hurry and start it and put it into reverse and let off the brake before i let the rpms go down it will spin the tires in gravel

 

Yea mine idles high also when I first crank it up, then it drops back down. Dont know why it takes so long to drop back down. Mine doesn't take that long. Might plug it up to a scanner or code reader and see if it has anything malfunctioning. It could be worse, could idle at over 2000 or 3000 rpm. I'd check it out.

 

Vacuum leak possibly? Check your hoses. If it does that there is definitely something wrong. Does it stall when you come to a stop?

 

no leaks codes or stalls just kinda annoying not really hurting anything i dont think...

 

You may not have anything showing - YET. P071/P074 lean codes are stored pending for 20 ignition cycles before throwing a check engine light. Symptom usually points to either a vacuum leak, or weak spark (how old / miles are on those plugs?) and/or restricted fuel filter. In these cases, the PCM throws more gas in to compensate. From what I read here, throwing the truck into gear at higher idle tends to wear on the transmission over time.