Can someone confirm what there Voltage is at the injector clip...
Can someone confirm what there Voltage is at the injector clip...
So i need to know what your battery voltage is and what your voltage is at your injector clip.
Currently on my car, I am seeing 12.5v at my battery, and I am seeing 10.9v at my injector clip. I am trying to track down why I have a loss of 1.6v. This is causing me all sorts of bad issues. But in order to confirm that this is 100% the issue I need someone to verify that I shoudl be seeing the same voltage at my injector clips as my battery.
Now a little more on this. I am seeing 12.5v at my Injector Resistor pack, which has been bypassed for High-Z injectors. So on both sides of the resistor pack I see the same voltage. When I tap into the +12 side of the injector clip, and ground to battery I see 12.5v, and when I use the ground on the injector clip and +12 from the battery I see 10.9v. So I am pretty sure that I have an issue between the negitive terminal of the injector clip and the ecu.
I have also swapped ECU, I am on an AEM EMS and I switched back to my stock ecu. The harness has not been hacked and slasched. It only has an AIT sensor soldered into the MAF harness, and a new MAP sensor. Those are both on the 5v circurit, I also see +12.5v at the Coils.
If anyone else has any advice on what to look for or what else to test to help track this down I am open to damn near anything.
Currently on my car, I am seeing 12.5v at my battery, and I am seeing 10.9v at my injector clip. I am trying to track down why I have a loss of 1.6v. This is causing me all sorts of bad issues. But in order to confirm that this is 100% the issue I need someone to verify that I shoudl be seeing the same voltage at my injector clips as my battery.
Now a little more on this. I am seeing 12.5v at my Injector Resistor pack, which has been bypassed for High-Z injectors. So on both sides of the resistor pack I see the same voltage. When I tap into the +12 side of the injector clip, and ground to battery I see 12.5v, and when I use the ground on the injector clip and +12 from the battery I see 10.9v. So I am pretty sure that I have an issue between the negitive terminal of the injector clip and the ecu.
I have also swapped ECU, I am on an AEM EMS and I switched back to my stock ecu. The harness has not been hacked and slasched. It only has an AIT sensor soldered into the MAF harness, and a new MAP sensor. Those are both on the 5v circurit, I also see +12.5v at the Coils.
If anyone else has any advice on what to look for or what else to test to help track this down I am open to damn near anything.
Well the ecu controls the ground side so you don't exactly have a straight path to ground, which could account for the voltage drop you're seeing. When the car is running (which i assume it's not when you are measuring with the 12.5v reading) the ecu is opening and closing the ground path, which will give you invalid readings using a multimeter. If you plugged in an O-scope you'd have a better idea of what's going on while it's running. If the car is not running then the ecu is blocking the ground path and messing up your readings.
If you're trying to get the battery voltage for ID injector battery comp values just use the positive voltage measured from the bypassed injector resistor to battery ground.
also, you said you're using an AEM so make sure the voltage that it says it's using for the battery comp table matches with what you're measuring when it's running and not running.
If you're trying to get the battery voltage for ID injector battery comp values just use the positive voltage measured from the bypassed injector resistor to battery ground.
also, you said you're using an AEM so make sure the voltage that it says it's using for the battery comp table matches with what you're measuring when it's running and not running.
Last edited by griceiv; Mar 14, 2011 at 09:26 PM.
KOEO the GND pin on the injector should be open. Put a test light on it and I bet it won't light up cause there is no real current on it. If you suspect an issue with the inj trigger wire then do a resistance test between the inj clip and ecu. What kind of "issues" are you running in to?
