hondamxer

I have a 2000 f150 v6 4.2. I went to work Thursday drove about 150 miles that day. It rode perfect. It sat maybe 45 mins. after I got home and I went to move it. It started fine and idled fine. I put it in reverse and it reved up and down quickly and stalled. It idled fine in neutral, put it in drive and rev same and stalled. I cleaned the idle air control with brake cleaner. It helped it for awhile. I started it and unpluged the iac and the truck idled real low almost stalling, pluged it back in and it reved high and went to "normal" idle. I replaced the tps. this didn't help. I unpluged the tps with truck running and no difference in idleing. Is this normal? should there be a difference in the idleing? I don't know what else to try and hope someone has had this problem and can help me fix it!! Thanks in advance for your help.

Good old Bill

Sorry to hear about your concern, have the same engine in my 02. Have you had any CEL concerns? Or actually is the check engine lite on (CEL). Would think, a code should have been thrown. I have read about other 4.2 engines with vaccuum leaks at the PCV valve. Question those comments as my PCV is located in the throttle body, has large hose for the crankcase vaccuum plumbing. Also has two small hoses 3/8 in size that have coolant. This thing doesn't even resemble a PCV. Maybe try cleaning the MAF located between the air filter and the throttle body. I know this hasn't been the answer you are looking for, but please keep me posted for my own future use.

hondamxer

I replaced the IAC and that has fixed it for now! It shifts hard into overdrive now though, but not all the time. Thanks!