It was killing and surging at idle for several months. I recently changed pcv elbow and cleaned throttle body and MAF sensor. Idles well now, no kill and no surge.

HOWEVER, it is and always has been way too strong at idle in my opinion. Even in traffic it takes a heavy foot on the brakes to keep it slow/stopped. It does sort of buck to a stop when downshifting, not violent but you really have to press brakes hard to bring it to a stop.

Yesterday I kept my foot off the pedals to test it and it climbed to about 15-18 mph without touching gas pedal. I even pulled up on the gas pedal from underneath with my foot. This strong idle cant be good for the brakes either I would imagine.

Any ideas?

 

Any codes? Multiple causes of a high idle, but it is indicative that some thing is not right. Check the codes and report back...

 

Sorry should have mentioned codes P0171 and P0174.

 

Those codes are lean bank 1 and 2. Too much air for the available fuel. Several causes, but I would bet a vacuum leak. Start checking everything. Could be simple like the plastic elbow by the PCV valve or some other cracked/rotten/disconnected vacuum line.

I always start with the simple stuff first.

 

I'll do that. I actually changed the elbow on pcv (mine didnt have an elbow originally more of a straight hard plastic tube with soft rubber ends that fit over the pcv nipple, the soft rubber was rotten). We replaced it with a hard rubber hose all the way across seems to be snug but I"ll double check it and the other hoses and see if I can find)

Anything else you can think of while I'm in there? What about the IAC valve its never been cleaned to my knowledge (130k miles).


Thank You

 

Fix the vacuum leak first.

Reset the PCM and allow it to relearn.

If you still have idle issues and you do not have any indication of a continued vacuum leak, then investigate the IAC valve (clean/replace).

If you skip straight to the last step, you will probably waste time and money.

 

So you changed the elbow at the PCV? Did you change the rubber elbow at the back of the intake manifold? The rubber elbow at the rear of the intake is a common problem.

Also, make sure the hard rubber hose you put in place of the plastic tube is strong enough that it doesn't collapse under vacuum. If the hard plastic tubing is fine, I would put it back with the new rubber hose ends

 

I will put that hard plastic tube back in place and make ends out of the hard rubber hose. Also I have not changed the elbow on back of intake I will have to look into that, not quite sure about location or which hose.

Thank You!!

 

Follow the PCV line. It goes from the PCV to the back of the intake. I suggest you buy one to have on hand, them swap them out. I posted this pic from another thread and this is the elbow you're looking for at the rear of the intake, under the IAC. It's only around $7 at AutoZone.

http://www.ebay.com/itm/like/251379083447?lpid=82

 

Thanks, but my particular vehicle did not have this elbow. It was more of a straight line. It was a skinny hard plastic tube with soft rubber ends that fit on the nipple of the pcv valve on one end and the nipple on whatever it hooks to one the other end.

 

That "whatever" is the elbow I described, unless the '04 doesn't have the elbow on the intake.

Can someone with on '04 verify if the elbow is the same as earlier models?

Look at the pic in Alloro's post #6. It's a '98 but yours may be similar in regards to the elbow.

https://www.ford-trucks.com/forums/1...when-warm.html