fuel cutting off 1991 190e 2.3

After rebuilding and reinstalling the motor in a 190e 2.3 8v. 1991 the car will start and run for about 7 seconds. A new fuel relay was bought but didn't cure the problem. There is good fuel pressure and if you jump the relay the car will run. However the timing can't be adjusted by turning the dist. and the tach doesn't work. I only have a manual up to 1988 and I have a bosch manual that I've been using to fix the problem. These say that the functions that are giving me trouble are related to the voltage relay. Is this true? Can I test this relay and how might I do this? If any other suggestions I'm all ears. It's starting to get to me so any help will be appreciated. Thanks in advance.