4AGE - Stock ECU not pulsing injectors?

[Puffy]

Need the expertise of the 4age conversion clan on this one.

Wiring a 4age into a datto ute.
Everything that I deemed essential is connected but she aint firing up.

Here is the situation.

When I pull the injector plug, my test light shows power to both pins.
Bridging the injector plug pins with a test light it should flash when cranking right?
This is not happening so this is why I think the problem lies with the injector pulsing.

Getting spark at the plugs
Checked that ECU IGT to Ignitor and back to ECU IGF wires are good.
Injector grounds are well mounted (normally located on the intake manifold)
ECU is also grounded to be sure.

Is there something else the ECU uses to trigger the injectors that I have missed?
Any ideas

[roadsailing]

pretty sure the ECU switches the ground of the injectors, they are always powered on the other side.

[wilbo666]

Your test light may not be able to light up quick enough to show that the injectors are being pulsed!

Try with an LED and a series resistor would be a suggestion

The ECU needs the signal that the engine is turning (from the dizzy) to fire...

Cheers
Wilbo

[Puffy]

Thanks guys...
Roadsailing - yep that is my understanding also. One side of the injector is powered by batt and the other by ECU which than alternates to ground and pulses the injector.

Wilbo666 - Glad you said that.
I did think about the test light reaction not quick enough but was not certain.
The dizzy to ecu plug in connected.

I will make a LED test light to confirm if the injectors are working.

Cheers

[BLK_20v]

Check the brown wire that attaches to the block is earthed properly... U'll pick it as there is about 4 earths in one.

And you've got the power right at the ecu.

IS the Fuel Open Circuit wired correctly too?

[Puffy]

Hi BLK-20v,
I checked the ground and ran another ground to the injectors to be safe.
The pump is engaging on crank and disengages a few seconds after cranking has stopped so I think the open circuit is wired ok. Looking at the diagrams, I dont think the ECU relies on the open circuit to pulse the injectors ???

[roadsailing]

I dont think the ECU relies on the open circuit to pulse the injectors ???

i dont either, my sprinter doesn't even have a COR and runs great.

[BLK_20v]

Yeah the FOC doesn't matter for injector pulse, but mentioned incase you had injector pulse and your light wasn't showing it.

You haven't used a bigport dizzy in a smallport etc? Pretty sure they aren't interchangable.

[wilbo666]

Hi BLK-20v,
I checked the ground and ran another ground to the injectors to be safe.

I'm a bit confused...the injectors don't have a GND so how did you run another one to be safe?

They have +12V on one pin and the engine ECU grounds the other pin to turn the injector on...!

Cheers
Wilbo

[turbo ke20]

ground to the injector??????? sniff sniff.......i smell a fried ecu

Unplug the ecu and check each earth pin individually.

Ive been caught out before with the same symtoms you have.

Put the clip of your test light to a 12v supply and the probe in the ecu plug to test

If you have spark this is most probably the problem

[Puffy]

Sorry.... I meant ran another wired ground to to the existing grounds (brown wires) located on the manifold.
Thanks turbo ke20.... I will do that.

Cheers - Puffy

[schnickles]

Id say its probably just the test light not reacting quick enough you really need an led or a noid light as mentioned. Have you checked to make sure the injector power does not turn off when you turn the key to crank as ive seen that before... also check if you clip your test light to earth and touch the injector - at the ecu plug (with ecu disconnected and ignition on) can you hear the injector ticking the reason i ask this is i wired one the other week that had been sitting around for a while and all the injectors were stuck closed so it wouldnt run, fixed that and it was sweet.

[Grega]

um.
which loom do you have and what color are your injectors? early ae82 or late ae93 or ae86?
in my ta22 --> 4age conversion i have a resistor pack on the injectors - plugs into a large yellow plug
if not there.....no injectors worky whatsoever...

[Puffy]

Snickles... Im starting to think it is the test light so I will need to get a LED one from somewhere. confirm.
Grega... it is a 92 with grey plugs, high ohm injectors so no resistor pack.

Thanks for the ideas.... hopefully can track the problem down.

[Grega]

right. ah they even dribbling?
i diagnosed this on my ae92 years ago - took the injector rail off and cranked the car - only to see one of the injectors squirt a bit of fuel out - i knew they were being pulsed, just they were blocked.
if you spray aerostart in the thing does it run and die?

the NOID light (for testing injectors) is effectively just an LED with a resistor.....i used a resistor on mine due to the LED not being suitable for +12v from the ECU. simple solder job though and effective. bend the legs of the LED double so you can get some purchase into the injector plug