Chevrolet Repair: 1985 Cavalier Fuel System, throttle position sensor, fuel pressure regulator

Question
I have a 1985 Cheverolet Cavalier 2.2 Litre.When we pull off the air cleaner and try to start the engine the injector just dripped.Trying to correct this problem we have replaced the fuel injector, the fuel pump,the sock filter, and in-line filter, as well as some ignitions parts wires, plugs , cap, button. We have good spark. We got the car running and was driveable but would suddenly stop. If u waited five minutes, it would run fine again. It did that about 10 times. Now at the fuel injector, the spray is reduced more than a drip but not the nice cone it's supposed to be. We've also checked and replaced the fuel pressure regulator. I don't know what else to look for...did i miss something? I was told to check the fuel pump fuse and relay for loose connections...that's been done....What do i do Now?! Thanks for any help u can offer.

Answer
Hi Dan,
Sounds like time to get hold of a fuel pressure tester.
Throttle body systems need about 13 PSI constantly.
They will run with about 10 PSI, but 13 is what should be there.
If you are getting 13, and have good spark, and the injectors are new, about all it could be is the crank sensor, and the ECM.
I just hate replacing parts till the correct one is accidentally replaced.
Get a noid light, which connects to the injector connector, and see if you are getting pulses of voltage there.
It should be battery voltage to one wire to the injectors when the key is on, and the other wire goes to the ECM, which completes the circuit to ground, according to inputs the ECM recieves, one of which is the crank sensor.
Another sensor is the TPS, or throttle position sensor. it is on the throttle shaft, and tells the ECM how much air is entering the engine, as well as how much fuel you would like. One possible problem with the TPS is if it is wide open throttle, it could be setting a "clear-flood" signal, which would keep the ecm from injecting fuel. Check the TPS.

But check the pressure first.

The literature suggests pinching the fuel return line to see if the pressure regulator is stuck open, but don't damage it during that pinching.

Van