I have a 1986 240 wagon, over 200,000 mi ,fuel injected was running great but now has an intermittent problem I cant track down. It doesnt seem to matter if the engine is warm or cold. Sometimes slow starting, when it is slow to start it idles fine but stumbles and backfires when I give it gas quickly but does OK when given the fuel slow and easy. other times it starts fine and I can stab the gas pedal and its fine but, when I give some gas slowly the RPM's go up to a certain point and then it starts stumbling again. Other times it runs great with no problem, with it being intermittent it is very hard to track down the problem part. Could it be the main fuel pump? pump relay maybe? or maybe the pressure regulator? I havent checked much into the fuel system yet. thought I would check with the fine people here before I started messing with the fuel system.
thanks Mark