Good Morning All,

First time for me on a forum. I acquired a 1989 Bronco 2 2.9L fuel injected. When I crank the vehicle, the fuel injectors do not open and spray fuel into motor (Node Light Tested). If I spray starter into the intake, it rolls over. I confirmed there is positive constant power to fuel injectors. It appears ECU is not grounding them out so they can release fuel. I have fuel pressure and new fuel injectors. Running fuel off external tank as I am ordering a new one. I don’t know what my next trouble shooting steps are. Should I replace ECU? What should I test?
All advice appreciated. Thanks all.

 

There is something puzzling me.
How do you know you have the correct fuel pressure? The fuel pump is supposed to be in the fuel tank , and you are not using that fuel pump.or are you?

I believe you feel the injectors are not working . Did you verify that no ground signal is coming to the injectors? How did you prove that?

 

Replacement fuel pump is running out of spare tank into fuel rail. Checked fuel rail pressure from valve on rail.

I disconnected fuel injector plug. I plugged node light in fuel injector plug and cranked motor. There was no blinking of node light.

 

If you provided a momentary ground to the injectors , do they inject? Must be very quick or could burn up injector.

pins 58 & 59 come off the ECA to provide the path to the injectors to ground them.
Pin #58, tan & red wire go to inj #2 and pin 59 ,brown wire go to inj #1.
They show a plug connection between the injectors and the ECA
The brown wire (inj#1) connects to a Tan and Orange wire at the ECA
The Tan and Red wire stays the same color to pin 58 on the ECA.
I would make sure the ECA has all good ground connections

We are sure the noid lights work, right?
I would suggest you find a way to verify there is continuity with those wires coming from the ECA.

 

Noid lights work. Rented them from auto parts store and checked them on the battery with alligator clamps.

I will pull the ECA in the morning and check grounds to ECA as well as continuity from injectors to ECA.

If both check out, next step is to replace ECA?

 

The ECU is supposed to pulse one leg on each of the injectors to ground potential. There should be a constant power source to each injector. If you are going to pull the ECU,disconnect the battery first. Upon removal, remove its cover. If you see some bulging or leaky electrolytic capacitors on the board, those are likely causing your problem. I believe there are three. If one is bad, replace all three. Do this only if you have decent soldering skills, otherwise replace the ECU only if you find this condition.

 

Super helpful. New ECA is $150 so likely just going to replace the whole unit if there are any issues when I pull it.

Is there anyway to tell if I am missing the ground for that part of the ECA to fire? I know it is getting + power from ECA as I checked with multimeter. Could the issue be missing ground for that part of the ECA to pulse ground for injectors? I am going to attach wiring diagram. Thanks!

 

I would be careful since that diagram is not for your particular vehicle.

If all the tests point to the ECA and you can get the right one, why not.

 

After replacing with a new ECA, it did not solve the problem.
What should I do next?

 

Something that is puzzling me, you spray fuel into the intake and the engine runs which tells us the ign syst is fine just no fuel coming from injectors..
If no signal is coming from the ECA to signal the injectors to fire,it is unusual for 2 circuits to have an open. Check the wiring from the ECA to the injectors. Make sure there is not a plug between them which could be the problem. I would check for a ground signal before and after that plug.
Don't overlook the plug that plugs onto the ECA. Check the pins on that too.


You say you checked the fuel pressure at the port on the rail, correct ?
How much pressure reading did it show?