The second one looks like the connector for the smog pump diverter valve so I'm assuming that was deleted. The first one I haven't seen before. I know what the connectors look like for all the sensors, the switches, and most every other electrical thing under there, but that one doesn't even look vaguely familiar. If there's a number on there, that would help. I think I can help you on getting it running better. It's important to make sure you have good fuel, air, and spark just like anything. I'd check the fuel pressure where the fuel filter goes and replace the filter. You want to see in the neighborhood of 13 pounds. I'd say eleven is the borderline, and anything less means replace the pump. Also make sure that your injectors are giving you a nice conical spray pattern. Anything drippy or otherwise sloppy either while it's running or after you turn it off is a problem with the TBI unit itself. A lot of people rebuild the TBI unit when they first buy the truck or car, and I think it's good, cheap, and easy preventative maintenance. With spark, you want to just tune it up. Plugs, cap, and rotor for sure. If the wires look iffy, I'd probably do those, too. I use all AC Delco ignition parts, and I suggest the same of anyone. Timing is important. I would try eight degrees BTDC and see how that treats you. Don't feel bad if you need to retard it a little, though. With air, make sure you don't have any vacuum leaks. The vacuum stuff is simple with TBI. Just do a visual inspection moving away from the TBI. It would probably be a good idea to replace the base gasket, too, as those are relatively fragile. If it's a high mileage vehicle, I can 99.9% guarantee that you have throttle shaft slop, which causes a vacuum leak. Not too serious, but I had bushings put in both the TBI in my Jimmy and the Quadrajet in my car to get rid of that. The sensors on TBI are just as important. Do you have a Service Engine Soon light coming on at all? That's a good clue in diagnosing sensor issues. If you don't have an oxygen sensor, you need one. I would check really well, and if there's not one, you'll have to weld a sensor bung, which I would do before the collector on the headers if it were me. A good post-purchase tune up item for TBI is the Coolant Temp Sensor, which I see threaded into the manifold in one of your pictures. What I'm thinking is that a sensor is not working right or not hooked up, and you're running in limp home mode, which uses very rich and inefficient mixture tables for the purpose of getting you to where you can stop if something's not right. This coupled with one or more minor problems is what I would be looking for. If you do have an SES light, you can get a paperclip, jump the two top right hand terminals on the diagnostic connector, turn the key on, and it's gonna do a series of flashes that you count to determine the code it's telling you. They flash in a series of three, and it stores three codes, plus a Code 12 (one flash, pause, two flashes) at the beginning and end of the sequence of trouble codes, which will also flash in a series of three.
