2.3 not start spray starting fluid it runs

[Coldair]

Ok here's what I have going on 96 2.3 checked the timing belt/timing is good. Checked for spark has spark, replaced tps (didn't read right on my ohm meter ) checked fuel pressure 38 psi. Spray starting Fluid in the intake starts runs tell gone the a dies.
I was just going to Let the truck sit tell I got all the parts to install the 302 But thought what the heck why not drive it in the mean time.

 

[RonD]

If it starts when you manually add fuel then all is well but no injectors or fuel pump.
If you have fuel pressure then it is the injectors

For all injectors to be off then computer is the problem.
BUT(big but) could be the computer is being told not to start the injectors.

The TPS gets 5volts from computer
The TPS sends back under 1volt if throttle is closed and 4.5-5volts if throttle is wide open(WOT)

If computer sees WOT voltage from TPS while starting it will turn off fuel injectors.
This is called "Clear Flooded Engine Routine", common on most fuel injected engines

Unplug TPS and try to start engine
If engine starts replace TPS
If engine still doesn't start then get volt meter out and test the now disconnected TPS wires, top wire should have 5 volts
Middle wire low or no volts, if it also has 5 volts then these two wires are shorted together

 

[Coldair]

Thanks for some info Ron. I did put a test light on the injector harness both wires had power no ground is that normal?

 

[tomw]

There is power to the injectors, and the power will be seen on both 'sides' of the injector. The computer provides ground to complete the circuit so the electricity can flow, and energize the injector. The ground is provided each time the injector is to fire off, and spray.
There are items called 'noid lights' that can be plugged into the injector connector socket and they will show flickering if the computer is trying to operate the injectors.
tom

 

[RonD]

Yes, +1 ^^^

When you turn on the key the EEC relay closes and powers the EEC(computer), the coil packs, and the fuel injectors.
Ford injectors only have 11-16ohms resistance, 0 ohms is no resistance, so if you pull off the injectors wire, key on, you will see 12volts on the Red wire and low or no volts on the other wire.
If you put the wires back on injector then you will see 12volts on Red wire and 12volts on the other wire because the 12volts is easily passing thru the low resistance in the injector to the other wire.

When you crank the engine, the Crank Position(CKP) sensor will send a timing pulse to the computer(1995 and up), the computer will then Ground and unGround the coils to send spark to the correct plugs and also Ground and unGround the fuel injectors to add fuel.

Cam Position sensor(CPS) is used to fine tune sequential fuel injection and spark timing once engine starts.

If CKP sensor or it's wiring was the problem then you would also have no spark, so a no start when you add fuel manually.

CPS wouldn't effect startup but will effect operation

'96 4cyl will have 4 separate Ground wires for the injectors, so a bad wire would cause a misfire but not a no start, 4 bad wires would be an extreme long shot

Just to confirm fuel pressure turn the key on and off while listening for the fuel pump to run for 2 seconds.
Fuel pump will turn on for 2 seconds each time key is turned on, it isn't quiet
If you can't hear it then that is the problem.

If you have fuel pressure at the fuel rail/injectors, then unplug the 3 wire connector on each coil pack(no spark) and crank the engine over a few times.
Pull out 1 spark plug and check it's tip, it should be wet with fuel
If it is dry then that confirms no injector pulse.

As tom said, a Noid light can also be used on a fuel injector to show if computer is Grounding it.
The injectors are only Grounded for a few milliseconds so a test light or digital volt meter won't work, and with an old analog meter(needle/gauge) you might see a slight pulsing while cranking engine IF there was grounding.