I have a 2000 f150 5.4 lariat 4x4 auto. When idling the rpms fluctuate and idles rough.. and after good and warmed up, every other stop sign I start to pull up to the truck just dies on me. I have a feeling my alternator my be screwed.. it gets hot after a while of. But battery charges fine from what I can tell. Did have problems starting till I hooked up the battery charger. Battery is brand new btw.

 

1 Clean / replace IAC.

2. Clean TB and MAF, EGR ( see Tech Articles section fer how-to's )

3. Pull any codes - post 'em ( lookin' fer misfires, lean codes, etc here )

4. Have charging system & batt load-tested.

good luck
MGD

 

I do have an iac and lean bank 1 & 2 code.

 

Please post the actual codes.

Possible vac leak ( usual suspect is the rubber elbow behind the TB - lots of threads discussing this - just drop the codes into Advanced Search & the'll pop up.

MGD

 

Erased codes yesterday and yet to pop back up..

 

Here's a video of the rpms. Don't mind the music. My cousin was with me.

 

Hey.

Always write the codes down before clearing.

While waiting fer them to reappear, at least remove and clean the IAC ( WD-40), the MAF ( with CRC cleaner) and the TB ( CRC TB cleaner).

Do the EGR passages as well - may need somethign stonger like carb cleaner fer that.

And - as mentioned search for the vac leak root cause and inspect it on yer truck. (171/174 codes, IIRC)

The video tells me nada - sorry. You wasted time that would have been better spent in maintenance and diagnosis. Are you serious aboot fixing this, or not?

Post back if/when codes reappear.

MGD

PS: - Hey Karl65, why don't ye git off ye ayss an' start pitchin' in ta hep?

 

Okay, just got home from about to do all the cleaning. One code has popped up since then.. P0171 system too lean bank 1.

 

Vacuum leak probably. Check the PCV system.

 

Ok so I've cleaned the maf, replaced the iac and the pcv valve. Attempted to clean the pcv hose. Still idling rough, has gotten worse. And 7 codes have popped up p0136 p0300 p0174 p0171 p1151 p1131 p0156.. but runs fine 2000 rpms and above.

 

2000 f150 5.4l.. truck idles rougher than dog ****. 1500 rpms and higher runs fine. I've gotten 7 codes so far..p0136 p0300 p0174 p0171 p1151 p1131 p0156. I've cleaned the maf and tb. Replaced iac and pcv valve. And somewhat cleaned the pcv hose. The elbow is fine from what I can tell. I replaced the intake manifold about a month ago and came with different setup for pcv valve in the rear so everything there is good. Thinking about replacing the pcv hose itself but having to order it. I'm all out of ideas of what to do next other than to take it to the local mechanic..

 

You already have an open, active thread on this issue:

https://www.f150online.com/forums/v8...need-help.html

Starting yet another thread for the same concern is against Forum Decorum, and just plain confuses folks.

Please desist. Contact a Mod to merge ye threads.

BTW - P0300 is a random misfire - you should get Mode $06 diags performed to see the extent of the problem, COPS, plugs, injectors ...?

http://engine-codes.com/p0300_ford.html

P-0136 - Bank 1 Sensor 2 fault: http://engine-codes.com/p0136_ford.html. This is a cat monitor and could be, like the code above it, related to another root cause ( intake air leak, etc). The fact that you now say the intake maniforld was changed could be a significant clue.

FWIW - it's best to include everything of value up-front to help folks help you - withholding crucial info ( like a I/M swap) isn't gonna help any....

 

Really bad vacuum leak now! pay careful attention to the elbow at the back of the throttle body. You dont clean those hoses. Sounds like you made the leak worse.

 

So did some tinkering and found that the pcv elbows are pretty deteriorated on the inside but no holes. The elbow coming from the pcv valve itself has collapsed and is being sucked closed. But when I pull the pcv valve/elbow out it sucks just fine? Could there be an issue with the pcv system? while idling I checked the other end of the pcv system, the hole on the driver side valve cover and there seems to be no suction coming from it? Should there be?

 

If your PCV lines and elbows are deteriorated and collapsing, you need to replace them!

I believe this is the correct one for your engine: