What would cause a rough idle?

[95RedTalonEsi]

I've had my 95 Talon esi for a little over a year now and, as on January first, it's started to idle rough, hesitate when I accelerate, and the mpg has dropped a bit too. Does anyone have any suggestions as to what could be going on w/ it? We've replaced a few things already. I was picking up a new thermostat and came our to the car not wanting to start at all (just today). We replaced the coil, but it still won't fire up. My fiancé moved the fuel pump relay a little and it acted like it wanted to start, but wouldn't. I'm at a complete loss....suggestions? Please?

 

[jimsgsx]

Check your plugs wires, boost leak test for sure. Fuel pressure. Check maf, ecu, fuel filter, biss. Man you pretty much need to check everything under your hood. Not the answer you were looking for I'm sure but its true. And where is rochester wa?

 

[p_o_s_pc]

Pull spark plugs check for oil on them.my 420a had the same issue.plugs were covered in oil. Cleaned them off and ran fine for a day. Obviously it isn't going to fix it permanently.
I also noticed the small coolant line , above the thermostat housing kinked, not sure if that effects it but check that as well

 

[tuurbo junkiiiee]

Maf is definitely a big one, same was happening to me when I noticed the Maf sensor was constantly coming loose

 

[PlanZero]

I'm convinced my Tsi runs like crap when it's extremely cold out. Unless I let her warm up for at least 5-10 mins in the morning, I have the same problems. The suspension's noisy, the door doesn't close right, etc. Unless its above 25 degrees outside. This morning she wouldn't start at all when it was -3, but by the time it reached 20 she started and ran fine. I know this was no help, I just had to vent.

 

[jbeaton9292]

Well when your saying its not wanting to start now im willing to bet its gonna be your engine coolant temp sensor on the tstat housing check the resistance on it the specs are somewhere on here if you search but i bet that is the problem