What else to look for? Idling,fluttering

[fishnmaine]

I know this is a subject repeating itself......But I did just about everything.....2004 sport trac with 62000 miles...............This is in the past 10 days...........OK rough idle fluttering at park 700 to 1200 rpm...... holding it in drive not so bad......replaced the wires and plugs runs smoother when I'm driving....cleaned the IAC tonight.....hoses seems fine no splits or holes that I can see and feel.......cleaned throttle body.....I didn't change the coil because it runs fine when I'm driving.....Does this make any sense???



Forgot to say NO Engine Light, Codes or Pending Codes



Thanks

 

[scott degroot]

The hose everyone talks about can appear to look good. the only real way to inspect it is to remove it.



You mention that you have no pending codes which makes me think that you may have access to a scanner. If so what are the long term and short term fuel trims at idle and what is the baro hz reading?

 

[fishnmaine]

l1tech,



Don't have a scanner.....went to the garage the other day for a sticker and told him to test for codes.....didn't use a hand held scanner connected to those expensive ones.....and said everything seems fine.....he thought it might be the plugs and wires which Ford are notorious for and it wasn't bad enough to trip a code ........So what kind of reading should the long term and short term fuel trims at idle and what is the baro hz reading be....and if not right what else could be wrong?

 

[Jerry Gerner 2]

Did you use Motorcraft or Autolite plugs? Ford doesn't like other brands.

 

[fishnmaine]

Autolite double platinum

 

[scott degroot]

Short term fuel trims should always be around 0 and they will usually fluctuate between -3 adn +3. What's more important is the long term fuel trims though as this is the "learned" value. Ideally we would like to have long term fuel trims at 0 but realistically if the readings are within 10 either + or - that is acceptable...not ideal but acceptable. On Fords anything that is over 15 + or - will set either a lean or rich code.



The baro reading depends on elevation and is solely calculated by the mass airflow sensor. This reading is one of the most important pieces of information along with fuel trims that I look at when diagnosing a rough idle or lean/rich condition.

 

[fishnmaine]

Ok with all that I said at the beginning of my post........a few other things happen twice now from a cold start the truck idled at 700rpm.....had to step on the gas a few times to get the idle up there normally in a cold start........when it warmed up it idled down to normal...then it fluctuated up and down a little........I unhooked all vacuum hoses to see if any splits or holes all is fine......could it be my IAC or MAF??????

 

[mookie]

Check out this post. It shows where the imfamous elbow is. My hose was bad (though split on top, not underneath like most) and started to whistle. I never got a code but after I replaced it, my idle smoothed out.