I have a 88 318i. The ground strap from engine to body came loose and car wouldnt start. Re-tightened ground strap now car cranks but wont start. Have power to coil but no spark going to distributor cap. has new coil,cap,rotor,and wires. Some one told me that computer might be fryed, is there any way to check that?any ideas would help thanks.

Yeah, that could be a possibility, the BMW electronics are very sensitive. Simply connecting the battery terminal with the ignition on will fry the ECU, and doing jumstarts as well. The best way to make sure is to have the ECU tested at your local Bosch dealer or BMW dealer.
Thats what happened to my 316, the computer fried and it would cost $1600 to replace, I was like "what the hell?" then I got another car. ECUs have come down in price, around $250 for a refurbished one, not sure where they have them.