With a good multi meter and a test light, you can check out the fuel injection on that bus. If it is fuel injection that it. It its running poor cold, check the temp sensor under the intake manifold and also check the cylinder head temp sensor on the left side cylinder head near the number three spark plug. Like I said, if its fuel injection, take the bentley book, a multi meter and a test light and check it out. Most every thing on this system will test out with a multi meter. Bus fuel injection it very easy to work on and it runs great when its tuned right. Don't let anyone talk you into a carberator. Good luck.