Rough low idle :confused:

[twalter]

I've got a 2004 Exploder 4X4 with the FlexFuel 4.0L V6 126,xxxish Miles
Last Monday i noticed that the x was idling rough around 500rpm. While in park or driving.
I spent today looking for vacuum leaks with carb cleaner, cleaned the MAF, Changed the Hose that runs from the intake to the evap purge valve thinger.
Broke off the two torx head bolts holding the TPS on and had to buy a whole new throttle body($400FYI)
Installed the new throttle body and fired it up. it idles around 1000 for a few seconds then drops to 500 ish rpm. While the rpms are coming down it runs as rough as it did before..

Its been a real tiring day trying to figure this one out. any help would be appreciated.

 

[Foo392]

Have you tried cleaning your IAC?

 

[twalter]

2004 does not have a IAC....i looked for it.

 

[Foo392]

Ohh, yeah, I remember, those are "throttle by wire", you may want to look into the PCM upgrade, I think there were people who experienced better idling afterwards.

 

[twalter]

The shop i took it to said its a misfire on two cyl and i should have back monday afternoon.

 

[twalter]

Wasn't a miss fire...shop put it on three different scanners and only the snap on on said it was a miss fire.

They cleaned the injectors with a ford recommended cleaner and that helped a bit, tried to enrich the fuel air mix with no results. They checked compression in all the cylinders and preformed a vacuum leak test. They replaced the vibration dampener and still no improvement. Re flashed the computer to the latest program and that seemed settle the problem. now the vibration comes and goes... only while in the 600 to 1000rpm range.


Still looking for a solution.

 

[bahlingb]

Did you try a smoke test on it for vacuum? How is the temp gauge after warmed up, could it be a T-stat? Any check engine lights/codes? Have the plugs and wires been changed recently? miss fire could be a bad coil as well did it tell you what cylinder has the miss fire? t-stat is a $15 fix coil is a $35 fix hopefully its one of the two.

 

[FordFool2]

We noticed last year our 04 while idling at stop lights started to lunge or lurch. Turned out it was struggling to idle. The fix: A new set of plugs. We had a little over 100K on the odometer.

 

[MrBean]

a buddy of mine had the same issue, after months and lots of diagnostics from different dealership couldn't figure it out...so he started throwing parts at it...and cleaning random sh*ts...finally fixed by replacing O2 sensor...stucked at rich so ecu keeps taking out fuel when coming to a stop and sound like it gonna stall at idle. easy fix. good luck