Hello,

I have a 2001 f-150 5.4 L. It won't idle when cold. The colder it is outside the worse the problem gets. I have to rev it up to about 1300 rpm before it runs smoothly. It idles very rough and the rpm will drop out to 100-200 or sometimes even stall out. It has been like this for about 6 months. I hope I did not damage anything else by leting the problem continue so long. At first (first month or so) it would run perfect once it warmed up but now it idles a little rough even after it is warm. Maybe I damaged a plug or coil by running it like this so long. It did have the check engine light on.

I read some other posts on this forum and decided to change the IAC. I changed the IAC and the dirty air filter. I cleared the check engine light when I changed the IAC.

The problem did not change at all but the check engine light has not come back on. It is still doing the same thing. If the check engine light would come back on I could get the codes pulled at the local auto parts store and post them here. The only change I see is that the base line idle RPM has changed from approximately 600 to 700.

Any other ideas?

Thanks for the help.

 

What about ur EGR valve,MAF,Air temp sensor on air intake ?

 

I am still learning when it comes to this stuff. Which one do you think I should I try 1st? I had someone else tell me it might be the temp sensor. Temp sensor is only $15.00 so maybe I should try that 1st?

Thanks...

 

Google "5.4 spark plug" The 01 and 03 years apear on consumer affairs alot. . . one post give the same description as you and then blew a plug out of the head. If that happens DO NOT GO TO A FORD DEALER!!!

 

Sounds like a vacum issue to me

 

I got new plugs for it. I will go ahead and change them out to see if there are any tell tail signs on the old plugs. Wow....this looks like it is going to be fun. It looks like a lot has to come off to get to the plugs! I will also check over the vacume lines again.

Ahaaa..... I just found my note with the codes it had before I cleared the check engine light. I hope this might help someone tell me the main problem here. I had auto zone pull these codes when the check engine light first came on 6 months ago. Of course they can't tell you what to do to fix it.

P0171 System Too Lean (Bank 1)
P0174 System Too Lean (Bank 2)
P0300 Random/Multiple Cylinder Misfire Detected


Thanks..

 

Clean you MAF properly, not sure what CAI you have, but I am guessing your MAF is gunked up. Also check for vacuum leaks like previously states, plugs and COP's can't hurt either.....if done correctly

 

Where is the MAC? What does it look like?

 

The MAF is the mass air flow sensor. It sits in the intake tube, attached from the outside, small 4-5wire connector to it. Between the throttle body and the air filter. Can't really miss it. Be careful about how you clean it though. I'm too lazy right now but there are some good suggestions on here if you do a quick search.

 

You sure you got a 300 code??? If so , change all your COP's - all of them.. That only happends when it gets really wet under the hood. There all F'ed..

Get new COPs on ebay for $100 @ Global Automotive..

 

http://www.fordf150.net/howto/clean-...low-sensor.php

^^^How to clean MAF^^^

With your codes it doesn't seem like its the MAF, but it probably needs a good cleanin anyways.

 

OK...... I hate to ask but what is a COP. Yes I did get a 300 code for sure. I have the print out from the auto parts store.

MAF looks clean. Could it have gone bad?

 

While it is good to ask questions, there is such a wealth of information on this forum, more specifically in the engine forums, stay away from Gen. Disc. it will just rot your brain Just do a quick search first, and I'm willing to bet it has come up here before. That being said, you need to take the advice of jbrew and replace ALL of your COP's, might as well do the plugs while you are there. If you do not feel "comfortable" then take it to someone who does or has done it before. The "stealership" will rob you for labor, so keep that in mind. Then clean the MAF and check for the vacuum leaks, get the codes cleared out, and go from there.

 

Eric, COP = Coil On Plug , It changes low voltage signals from the powertrain control module (PCM) to high voltage pulses. It produces the high voltage pulses to the spark plugs. They connect directly to the sparkplug, you have eight of them - one per cylinder.

Autoparts resale is about $50 - $60 a piece. The dealership charges $70 - $90 a piece.

Globale Automotive, an eBay store, charges $100 for all 8, so that's pretty much a no-brainer where to purchase.

Theres two types of boots in the pics - The Heavy duty Ford factory boots that use brass fittings with a copper conducter and the regular cheapy boots that come with most COPs..

 

Thanks you so much for the info. I will get the COPs off ebay tonight. I hope it works....