Ideas and info. HELP?

first of all, i have a 1996 240 w/ 75000 mi. and used to be a consistent 16.5 1/4 mile car but now is running @ best HIGH 17's.  If any help the car ran like a bat out of #### when the check engine light was on (go figure) and when it suddenly went off the car would not start one night after it rained.  when it finally started on the first revolution after i took a peek under the hood it had very little power and now takes 1-2 for the oil light to turn off after startup.  PLEASE HELP.  also it will run alright when it really cold out.

oh yeah, i meant 1-2 seconds