I have a 1989 245 with 169k miles. I had the check engine light go on. A couple days later the car began to idle extremely low after starting, almost to the point of stalling. A few days later still, the car would not start, even with an attempted jump start. I reluctantly took the car to my mechanic. He checked the charging & starting systems & found nothing. He had to replace the plugs because he said that they were full of gas, adding that the car seemed to have been running "full rich" at some point earlier. He gave the car a tune up. He also cleaned the throttle plates, I think saying that that should help with the starting problem.
When he hooked up to the computer, the code coming from the car was a Code 113. He said that because of the age of the car, his diagnosis computer can only tell him that the code relates to the fuel injector system & doesn't give the specifics of the problem. He reset the check engine light but it came back on. He said that in order to fully diagnose the problem, I would have to take the car to the Volvo dealership.
My question is this. Any ideas what the problem could be from what I posted here? I bought this car recently & have put as much into it as I have paid for it. I'm now in neary $4000. I fear getting taken to the cleaners at the Volvo dealership. What's the worst case scenario for repair costs in this matter? Should I just get rid of the car? I already fixed everything!
Any insight would be helpful.

Thanks,

DW