I have an 87 245 thats getting poor gas milage, having trouble maintaining idle when cold, almost dies when i put in reverse after staring it up in the morning, hesitates when i first gas it after putting it into drive, and puts out a little black smoke when i accelerate hard at highway speeds. The air mass meter seems to work, it idles rough when I unplug it and races then idles well after I plug it back in. I tried to check the coolant temp sensor but can't get to it, do I have to take off the intake manifold? I tried to see if the injectors were gunked up but after removing the bolts that secure the fuel rail, I can't pull the injectors from the manifold. I recently replaced the main relay and in tank fuel pump, could these have anything to do with it? I've heard this could be a problem with the fuel pressure regulator, but how do I test this? Any help would be greatly appreciated.