I have a problem with my '94. It has 215,000 miles on it and has never had any engine work other than valve adjustments. The head gasket started leaking coolant to the outside of the head so I had it replaced. It had been smoking some and running rough when the engine was cold before I put it in the shop but nothing like what it is now. After the engine warms up it clears up and runs great with no smoke. Someone said it could be the injectors. If so, what should I replace them with?