Response:
1) Disconnect that amp and subs.
2) Sounds like something is drawing a lot of amps. Has he been blowing fuses and replaced them with a higher amp fuse? Do any wires feel hot or warm. The fan belt could be over tighten,(this is bad for the bearings). Get it to a garage and have them check it.
3) One of the sensors is bad. Check your voltage at each sensor both cold and hot and compare to specs. Usually high voltage (battery voltage) is a cold cycle circuit. Low voltage (half battery voltage) is the run or warm circuit. This triggers the ECM to set the cycle for ignition and fuel pump. A common problem with the distributor model 4 cyl was the pickup coil and reluctor in what was known as the "Hall Effect" Ignition.
4) hall effect is possible. an automatic shut down relay is possible. another strange thing is the map sensor. these are all easy checks to find out no meters or other things. start with the shut down relay which is under the hood in the relay center and switch it with another relay of the same number like the ac or what ever and see if it runs when warm. for the test on the map unplug the vacuum and see if it runs (it will act flooded but it will run) if it is the map and if all else fails it can be the pick-up coil know as the hall effect. in the distributor flat plate their when cap is removed lol and have a great day.
