Fuel Injectors

I have a 1999 Ford Escort SE car. It has approximately 109,000 miles. My car died as I was driving. It began to lose power and when I tried to give it gas it eventually died. We let it rest for about 30 minutes and got it to jump start. It wouldn't go over 40 mph even though I kept giving it gas. It began to clack heavily and died. When we took at look at the motor, we took the cap off the engine oil and it was smokey. I took it in on a weekend and the mechanic told us I needed a new motor. I brought it back home. It's been sitting for a year and my dad finally took a look at it. There were some of the fuel injectors not working properly so he cleaned them out. Gas blew out of three of them after he cleaned them, an improvement from before. The car still won't start. He took them off again and now only 1 has gas going through it. I was going to replace the injectors but is there anything else we need to be aware of i.E, computer system, fuel pump, etc? Just two weeks before it broke down I had a tune up. I was experiencing problems idling at stop lights after this was done. I took it back to the shop and they told me trash may be trying to push through. In addition a few months prior I had the timing belt replaced.