I replaced my coolant temp sensor this weekend. In the process I popped off the distributor cap. Now when I start her up she darn near dies seemingly missing. I have checked and rechecked my dist. cap and its tight, lined up, etc. After its run a bit seems fine.
At the same time I did fill up w/ 87 octane regular (been filling up with ethanol free since the car sits for a while between start ups) the day before.
Any ideas? So intermittent hard to nail down.

 

Perhaps some of the spark wires aren't completely seated (either on dist. or plugs) when removing the cap. Is there any way moisture was introduced when you opened it? Might not be a bad idea to lightly sand the rotor arm, get some of the carbon buildup off of it.

I doubt gas would cause it to stall/miss. I usually run 89-midgrade in my 240, it feels better, and my mileage bumps up 1-3mpg.

 

Hate to even admit it but I have to... Cleaned up the rotor and shes purring like a moose again.