98 Escort rough idle

I picked up the "new" Escort on Sunday, and it turns out to be a former Coca-Cola fleet vehicle; service vehicle I guess. Reading between the lines of the inspection records, it seems like it was used
regularly from 98-2001 and then only very intermittently (less than 1,000 miles on it during the last 12 months). There is an open recall on it for something to do with the OBD2 module - the TSB summary implies that whatever this fix is, it's just a software upgrade.
The only real "issue" I have with this car is something that sounds like a VERY rough idle. It vibrates the whole vehicle, sounds almost like it's missing a cylinder :) RPMs are approximately constant. This sounds weird, but the roughness seems to get slightly worse if I turn on the cabin blower. You really notice this noisy mode when parking.
I haven't had anything open or unscrewed yet, but I'm wondering if this could be dirty spark plugs.
It has to go into the dealership for the OBD2 recall next week, so they will perform a "standard multipoint inspection", but I'd appreciate any thoughts on the issue.
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Check the simple things first: Closely inspect all the vacuum lines for cracks ,poor connections etc. Replace the spark plugs and PCV valve.Add some fuel injector cleaner to the gas tank. My 95 escort ( 1.9 ) has never had a very smooth idle: Selecting neutral should reduce the shake. "Lewin A.R.W. Edwards" wrote:

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Hi,

You know, my second thought is vacuum leak because it *SEEMS* to get slightly worse when I turn the cabin air away from the OFF setting and I can hear the vacuum pulling the mix door around... Not sure where to look at that, but I guess I will start by popping out the console.
At least the PCV valve is easy to replace; it's right on top of the engine and labeled "PCV VALVE" in big friendly letters :)
BTW, going into N does reduce the shake quite a bit. Maybe the thing is just working as designed.
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Check the vacuum lines in the engine compartment.There should be an emmissions decal under the hood that shows the routing of the hoses.Good luck.
"Lewin A.R.W. Edwards" wrote:

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