I have a 94 nissan sentra xe. I have redone the timing and checked it numerous times... I have changed the spark plugs, ignition control module, fuel injector as well as service the new ones with new orings and pintle caps. Recently installed new alternator, camshaft, and filled tank with fresh fuel since the old one had sat in there for eight months so I had to get it out. The spark when I checked it seemed kind of small and red.. shudn't it be blue? Car seems to want to start.. what could be causing this?

You have done a lot of good things to your car. I recommend replacing the coil every 120,000 miles or 10 years, whichever comes first. Be sure to test all under hood and under dash fuses with a test light or multimeter. If the problem persists, loosen the distributor and advance the timing, if the distributor was not indexed. This is usually done by slightly rotating the distributor counter-clockwise (CCW).

If the timing belt previously broke or slipped, be sure to remove the spark plugs and check each cylinder's compression. It may reveal hidden damage to the valves, pistons, or head.

You have done a lot of good things to your car. I recommend replacing the coil every 120,000 miles or 10 years, whichever comes first. Be sure to test all under hood and under dash fuses with a test light or multimeter. If the problem persists, loosen the distributor and advance the timing, if the distributor was not indexed. This is usually done by slightly rotating the distributor counter-clockwise (CCW).

If the timing belt previously broke or slipped, be sure to remove the spark plugs and check each cylinder's compression. It may reveal hidden damage to the valves, pistons, or head.

Well the car has 135k miles on it... the coil doesn't look like it's been changed in it's 20 years of existence but I just tested it with a resistance test based off the service manual specs... the coil wire specs are 5k ohms per foot... the wire is about 8 in. and tested out at 3k. The primary resistance on the coil should be .9 ohms based on specs... the test showed 1.2 ohms... the secondary coil resistance should be 13k ohms.. it tested out to be about 12.1k. I don't know if I should change the coil since it's all pretty close to specs... but then again shouldn't it be exact?

If the coil measured out of spec, that is reason enough to replace it. You stated that the spark was weak (redish not blue) so I'd change it out.