Hey Scotty! ( or anyone else who can answer )
I have a 07 Ford Escape with 209k miles, over the past year its had some issues. Currently I've had a rough idle but the idling rpm is normal, engine mounts are fine, IAC and EGR valve are fine, replaced all sparkplugs and ignition coils, replaced alternator, no vacuum leaks, even new hoses on some, clean air filter; Used 3 different scan tools and not a single code. I'm wondering if it has something to do with the fuel pump or filter but I wanted some advice before replacing another part.(at this rate I may just replace the car!)
some issues are: loud vibration in cabin while idle in gear, especially in R, lack of acceleration, and horrible gas mileage and had an instance where it was sounding like I was going to stall out.
With those miles on that car I would also look at internal wear. Timing, valves, etc.
For the bad gas millage, you could check the MAF sensor. Since it's a vibration it could possibly be the drive shaft or wheel bearings, even warped rims or bad tires.
Measure the pressure on the rail. Also, monitor record live data (you may have already). I find this helps me with weird problems by being able to go back and look at the data (waveforms usually) synced and displayed on screen in the comfort of my chair/computer/info : )
Won't hurt to double check/clean that IAC...I'd also spray around the TB and IAC with soapy water...might make a temp seal and you notice the engine running better when it happens.. if it does.
