Fuel Injection Problems

[EagleShadows2]

I have a 1988 Bronco XLT 5.0 and cant seem to get injectors to spray any gas into the engine.I have replaced all the components including the regulator.Pressure is 37 psi at the schrader valve.heres where it gets tricky...-I bypass the fuel relay because it doesnt let the pumps run unless I probe the tan and green wire with my test light.When i do that the relay clicks on and pumps start-BUT they do not cut off until I either pull the light out or cycle key off....What could cause this lack of ground in the relay???And why doesnt the relay shut off when pressure is reached??The pump obviously shouldn't run continuously if its not running.It does run fine when I rig up gas to trickle into manifold at the throttle body and I have power at the injectors.They just won't spray gas into cylinders(when i check plugs they are dry as a popcorn fart)Any help will be appreciated!!!!!!!!!!

 

[Seabronc]

Welcome to the Zone >< <'> . Post in the introduction forum section and include some pictures when you get a chance. Also, add your truck vitals to your signature page, it will help in the future with any other questions you may have.

The fuel pump relay and the injectors are completely controlled by the EEC. The EEC supplies the grounds for the fuel pump and the injectors. You are providing a back circuit that bypasses the EEC control to the fuel pump. Since the EEC is not providing grounds to these devices, I would first check all connectors between the EEC and the engine compartment for corrosion and tightness.

Good luck,

>-

 

[69bronc347]

when you turn the key on the engine control module(ecu) turns the pump on fro 3-5 seconds to prime the system, then when you start the engine it runs continuosly until the engine is shut off. when you jumper the relay you bypass the ecu. the fuel injectors are triggered by the ecu, from an input from the cam camshaft position sensor which is in the distributor. the fuel injector have 12v when the key is on and the ecu pulses the ground. no that you understand how the system works, what is the issue with the vehicle, no start? do you have spark?