Rough Idle... Frustrating

[joefnh]

Here is an update to an earlier post on rough idle on a 4.0L XLT

I have read several of the threads on rough idle and have attempted most of the possible fixes, so far nothing has worked. Here is what I have tried:

1.) Clean MAF with approved cleaner

2.) Ran 1 treatment of Seafoam (16 oz) through air intake vacuum hose near IAC. This should allow for even distribution to all cylinders.

3.) Cleaned IAC. Note: could not find felt filter pellet mentioned in another thread. This version of the IAC could not be opened to expose the filter. Is this a problem? Is the felt filter normally found on an 03 4.0L?

3a) Replaced IAC with a new one from the Ford dealership, no improvement
4.) Replaced plugs with Motocraft platinum.

5.) Ran 1 can (16oz) of Seafoam through the fuel system with a full tank of gas (87 octane)

6.) Changed oil / filter 5W-30 synthetic Mobil 1 Fram Xtreme Guard filter

7.) Replaced fuel filter (Fram)

8.) Replaced air filter (Fram)

9.) Checked for vacuum leaks, nothing found

So far nothing has helped. This engine has only 35K on it, any ideas on what might help??

--Joe

 

[oso2324]

Disconnect your negative battery cable for a 15-30 minute period or so to clear computer. See if that helps some. Buenas suerte. Mike

 

[TPLYNCH]

In the future, PLEASE don't post a new thread. Just update your existing thread. Helps us keep track of what's what and saves bandwidth.