Injector always firing

[darkiller_666]

My number 4 injector is constantly spraying. Do the injectors all fire seperate or could i steal the signal from one of the others and have it spray the right time?

 

[Dsmj89]

Clean the connector where it plugs to the fuel injector and re-try it. It's not supposed to be firing all the time.

 

[darkiller_666]

I have cleaned and checked it numerous times. The number 4 injector is getting a signal from all of the injector ecu pinouts. Im still wondering to two injectors fire at the same time or all they all different?

 

[Dsmj89]

Correct me if i'm wrong but all injectors are supposed to fire at the same time when supposed to.

 

[darkiller_666]

Does anyone have a better understanding of the injector firing and how the ecu controls the signal to fire them?

 

[the_mork]

Injectors fire independently. IIRC one of the wires from each injector goes directly to the ecu. I cannot say for certain but it is fairly common for the "trigger" wire going to the ecu to be a switched ground so the wire could be grounding out on something which leaves the injector on.

 

[darkiller_666]

So what if i run a wire directly from the ecu to the injector? Thatll let me know whether it is the ecu signal or the wire grounding out?

 

[slowgsr]

Injectors fire in banks of 2. So our engines its 1/4 and 2/3 I believe.

Remember, these injectors always have 12V, they get fired by getting a ground signal from the ECU.

Heck.. Im not 100% which 2 fire at the same time so do this. At ALL your injectors, you will have 1 color at each clip... this will be ground. Than 2 injectors will have matching colors on the other side of the clip, and the other 2 will have a different matching color. This will tell you which are banked together.

It sounds as if you may have a short on the signal wire leading to the injector that is staying on all the time, check the harness first.

 

[slowgsr]

Injectors fire independently. IIRC one of the wires from each injector goes directly to the ecu. I cannot say for certain but it is fairly common for the "trigger" wire going to the ecu to be a switched ground so the wire could be grounding out on something which leaves the injector on.

They do not fire independently.. They fire in banks of 2. Its extremely rare to find a car that has independently fired injectors, and to change setups on our cars, gains are limited to 0.2%. Its very little. Proper term for our cars is sequential injection.

OP, goodluck. You can't run a wire right from the ECU as our cars use resistor packs since we have low impedance injectors (2.5 ohms) You need to check that harness, just start tracing wires.

 

[darkiller_666]

what if i try connecting the injector wires together after the resistor? I split the harness open and checked and retaped all the wires seperately all the way to the firewall.

 

[the_mork]

The injector wires go all the way back to the ecu and certainly can be controlled individually using something like evoscan. I don't see a good reason why they would be triggered in pairs but like I said I can't verify that for certain. You'll need to trace it through the firewall. I would suggest starting at the ecu and working your way back.

This has some extra information but you can use it to find the wire you need.

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