Chevrolet Repair: no fuel flow in chevy van, g20 chevy, flood mode

Question
I have replaced almost everything in the van an I still get no fuel flow into the injector body.
I have a 1988 g20 chevy van 305 auto tranny. I have replaced the fuel pump 7 times  cleaned the fuel lines  2 times cleaned fuel tank. 2 new brains new coil, dustributor ,cap an rotor, radiator, hoses , spark plug wires  dont know much more I can change that relates to the problem  , can you help?


               don dyer

Answer
Hi Don,
Have you unhooked the supply line at the throttle body to see if fuel is getting there? And, if so, what kind of pressure if you clamp a gauge on at that point?
You should have 15 PSI or so.
If you have that pressure when a gauge is connected like that, but the pressure drops when connected correctly, I would suspect the pressure regulator in the throttle body is just returning all fuel to the tank.
Another way to check, is find the flex hose on the return line, and squeeze it closed with some kind of clamp that will not permanently damage the hose, but will cut off flow back to the tank.

Now, if you have about 13 PSI at the throttle body, but just no fuel getting into the throat, You could have plugged injectors, or not operating injectors.

Get a noid light to see if there are pulses of voltage to the injectors.
You should actually have battery voltage to one side of the injectors when the ignition is on, and the ECM just pulses ground on the other wire.

Crank sensor signal is necessary for the ecm to pulse the injectors.

A TPS sending a wide open signal could cause a clear flood mode, and not inject fuel.

Van