this? Loose plug, or clogged fuel filter? 00L with 9500 miles, using only Amoco 93. Wouldn't loose plug be covered by warranty? How about fuel filter since it's not even close to factory recommended change mileage? I do know some of you change at 10K? BTW changed to K &N panel filter at 5k, so that shouldn't be it since relatively new with no cleaning/reoiling? Thanks for any info!

 

I just noticed this week that my idle has gotten rough too.
it has seemed to "miss" once in a while...
02 with just 10k on the clock...fuel filter?

 

After a recent oil/fuel filter change I have noticed that my L is running much smoother at idle. I bought the truck with 18,000 miles and I expected the fuel filter was never changed. This was one of the easiest/quickest changes you could make to rule out possible causes. The filter was only $12 from the dealer and I put mobile 1 5w - 30 full synthetic in her. Good Luck, Jim

 

Jake, those are considered wear and tear items. Change the fuel filter. My stock plugs at 18000 miles looked like crap, and three were loose, change those too. These fule filters are crappy and need to be changed often. I suspect this rough idle is caused by your plugs though. There is actually a TSB out for the rough idle problem.

 

Interesting your truck idle getting bad at 10k, just about same as mine. Brasil, I realize plugs and filters are considered wear items,but if there are failure issues long before recommended changes, think it would mitigate this? Any help on TSB for rough idle? For all 5.4 or only L? thanks again guys!

 

Jake: I would look for a vacuum leak--worn, cracked, loose hoses. The plugs could be worn or loose. If loose, they don't always complete the ign. circuit to ground so a miss could develop.

If your idle rpms are surging and it trys to 'die', then it could be a dirty or worn IAC valve. It's easy to unbolt and flush out with a solvent until the vane inside it moves back and forth smoothly.

Dan

 

Does this consist of changing out the plugs? Cause I've had mine in a few times for this problem and no luck yet IAC changes, MAF cleaned, Updated computer, ect... no dice

I hope its for new plugs, cause i will just give them a set to put in and get free labor

 

a search on this issue 330+ posts because of this common problem--that fords seems to know about! Most likely culprits, in decending order are: 1. egr valve & pintle 2. Leaky heater hose over number 4 coil pak ruins this coil & plug 3. IAC which Dan referred to. Supposed to be most prevelent on 2000 and earlier 5.4, not just L? No indications for 01 & 02? According to thread, ford mainly disavows this problem as being "characteristic of this engine"! Some are suing or going through arbitration process, or their state's "lemon law" process. Interesting reading, but should start about midway to save time.

 

Jake

I just put denso plugs in my truck and I can feel that it does
idle smoother. if your stock find out what plug I think it's IT16.
My truck would shutter at idle some times to and it is 2002
with 4000 miles. Good Luck!!


JEFF

 

your 02 with only 4k. Guess they haven't corrected problem? Although the "search thread" is a b****h to wade through, plugs don't seem to be the problem if you read previous post. Plugs or raising idle slightly only masks core problem. If they claim you don't have a problem, print out 330+ post "rough idle" search thread and jam it down their throat! Good luck!

 

Jake

I won't take my truck to the dealer. but my idle problem don't sound as bad as yours. plus I have mods and I don't want to
here the bull sh*t! the plugs did help me.

JEFF

 

really that bad! However, I appreciate your input! Luckily, I have a really good SVT dealer with 2 good SVT techs that I've gotten to know personally. One owns a L with mods. You might clear up one last thing for me though? Don't most aftermarket plugs, including those you mentioned have a fairly short life of 10-15k miles? Thanks again!

 

Why would aftermarket plugs have shorter life? I would think a copper plug about 25000 or more and a platinum about 50000 or more? Not sure tho.

 

Try cleaning your mass air flow sensor, I just did mine and it made a big difference. I use carburator cleaner, I just spray the little sensor wires off and let it dry, it takes less than 5 minutes to do, you will notice a difference and it won`t hurt the maf sensor at all.

Larry.

 

well I dont have a lightning but I've recently been having the same problem on my XLT 5.4L. Tried so far: changed plugs completely, changed fuel fitler (about 20,000 miles ago actually), completely tore apart the throttle body and the entire throttle assembly and cleaned thouroughly, checked for vacuum leaks as best as I could and found none, cleaned the MAF sensor, replaced the IAC valve. nothing yet. I'm getting some free flow cats installed in a few weeks though I doubt that will help, I just want them . I'm afraid to take it to my dealer because I'm sure what the response will be... "you've got aftermarket air intake, aftermarket headers, aftermarket exhaust... that's your problem... $100 please".
Things I'm going ot check in the future are Throttle Position Sensor, going to install an aftermarket throttle body (edelbrock/bbk), going to clean the Idle Air Temperature Valve to see if that will help. If nothing else works I'm going to try to find a stock air intake and install that, to see if the problem is with the K&N FIPK.