I just bought a 1994 bmw 318i and when i was installing the stereo i cut the power wire. it sparked and now doesn't work so i was guessing fuse. all the fuses looked good so does anyone know if there is another fuse box somewhere on the car?

Have you checked for voltage to the injectors? If all of them are not working it could be something as simple as a blown fuse or a faulty relay. Try this website as there were some updates done to some 3 Series models around 2007.

fuse-box.info/bmw/bmw-3-series-e90-e91-e92-e93-2005-2013-fuses-and-relay

Did you replace the spark plugs with the same brand recommended by ? Might also what to go over all the wiring harnesses, you disconnected when replacing the exhaust. Might of pinched a wire.

On the 1994 318ic my advice is to cut the car in half so you can get to the upper mounting bolt on the starter :). If you don't want to do that, you have to remove most of the intake plenum, fuel rails, knock sensors, temperature sensors and oil pressure sensors and oil dipstick tube to get access to the bolts and wire connections on the starter body. Our car is really nice for what we use it for (towing behind a motorhome) and is in excellent condition but I would never consider another BMW after having worked on it a few times

Read more: http://wiki.answers.com/Q/How_do_you_change_BMW_318I_starter_motor#ixzz1xVChjQrw

you most likely have blown a fuse, check the fuses in the fuse box.....cheers.

Verify the TDC Cam sensor on the left front of the engine, disconnect and clean it and reconnect.

check the brake-light switch itself.

Rotor, cap, distributor, wires, etc...

the fuses u are looking for are as follows:
From the top left first row its# 4
then the bottom row its # 19
I also wanted to point out. from 1989 to 1996 the brake switch was the common failure for bmw's
the series it included were 318i, 525-540i, and all 7 series. if the fuses dont fix it.. its the switch
located under a panel u need remove on the drivers side on the steering collum

You are correct on checking the sterio, just 12+ and ground to see if it powers up. Fuse 25, in your fuse box should be numbered. If not, just pull them one at a time to see which one got fried.