High idle things to check?

[Chriscpr84]

so I've been having an issue with a high-ish idle (1,200 rpm) and I was wondering what are some of the things I can check myself. I've already looked checked for vacuum leaks.

 

[Adieu]

Thats beyond highish, thats crazy high... 1200 rpm is more like cruise speed on rural highways

 

[Chriscpr84]

Yeah I understand lol. That's why I'm looking for things to check on tomorrow.

 

[NevadaGeo]

What engine and model year are your referring to? If you have a new Expy, I would take it in under warranty. May be a computer issue?

 

[stamp11127]

Use a scan tool to monitor sensor readings starting with engine cold up to operating temp. You would be looking for any that are out of range compared to the rest of them. Once up to temp check the operation of the throttle body with the scan tool. It will have a min & max reading during operation. Idle reading and wot. Compare the min to the specified amount that it should be.

 

[Chriscpr84]

It's a 2008 with the 5.4L. So no more warranty. As far as the scan tool goes I guess I will have to buy one. Can you recommend a decently priced one?

 

[stamp11127]

All depends on what you consider "decent priced". The software and cable for my VW project cars cost @$475.00 - but is necessary for the proprietary vw code definitions. Just another tool in the toolbox...

Check tooltopia.com for obd scan tools. OTC and Autel have been reliable products so far.

 

[Chriscpr84]

That's way over my budget lol. I guess I could just take it to the ford dealership and have them look at it I guess. Just didn't want to pay them for something I can do

 

[stamp11127]

That is nothing in this industry. The latest Snap-on scan tool with all the bells & whistles is @$20,000 - give or take.

You can get what I would consider a "decent featured" scanner for less than $200.

 

[ExpeditionAndy]

If you only use it once in a while Harbor freight has about 7 different ones.

http://www.harborfreight.com/catalogsearch/result?q=obd+ii

 

[stamp11127]

If you need to diagnose a problem your scanner should be able to graph at least 2 sensors at the same time - more is better. Usually the more you invest the more modules it will be able to communicate & control.

 

[Chriscpr84]

Okay I'm buying me a USB OBD2 reader tomorrow for my laptop. What is the best software to download for it and what exact readings should I be looking for?

 

[stamp11127]

I haven't used it but I've read about members on here recommending forscan.

http://forscan.org/download.html

 

[Chriscpr84]

Okay so I finally got around to reading my sensors and everything came out good. One problem I did find is that my idle is reading about 670 on the scan tool but my rpm needle in the vehicle isn't reading wrong. How would I go about getting that calibrated?

 

[Boose]

Just out of curiosity, how does it sound? It's pretty evident by ear when a motor is at idle, vs 1,200 RPMs. Especially the 5.4 if the cam phasers were never done