I have changed lots of plugs in my life but what happened. Here is my story.
I had a problem after a plug change. Why? Did I break something in the ignition. I need recommendations for next time.
1997 855 GLT 75,000 odometer miles.
I just installed a set of Bosch #7555 (FR7DC) plugs that I purchased from IPD about 2 years ago. They replaced some Platinum 4 Bosch units that began to misfire intermittently after 15000 miles (never again will I use them).
Why did the engine have to be cranked over for a minute to minute and a half before finally firing all cylinders up to the engine idle speed? (ran real rich and then leaned to normal through the start up). Are the plugs the issue or is it my install procedures?
The car now starts and operates fine, but how can I avoid this again? I hope the long cranking period did not screw up my car?

My plug change procedure:
Removed the head cover plate, detached the turbo crossover pipe, detached accelerator cable, carefully pulled each Bougicord from plugs, removed each plug with 5/8" plug socket with 1/4" drive ratchet, sprayed aerosol brake cleaner into each plug hole to clean the plug female threads, verified plug gap, applied a slight bit of anti-seize to each plug, installed to proper torque, reversed procedures and had my long start up problem.
What did I miss?
R.E.C.