Aftermarket ECU - Voltage difference vs Battery rewire

[mrsr32]

Hi

With the way the ECU power is setup, the voltage difference is about 0.70v on my car.  Most aftermarket ECU's only need power on pin 45 unlike the stock system which takes power from the ign to pin 45, then gnd's pin 16 for the 2x relays to kick in and then feed power into pins 49/59.

Has anyone rewired the relays so that they feed power into pin 45, which would mean the ECU voltage and injector voltage should be the same for better tuning?

This would involve switching the relays from gnd to 12v switched and then use a feed from the relay into pin 45.

 

[GTSBoy]

What is the voltage at your pin 45 and at your pins 48/49? Is the 0.7v difference there? If so.....the problem is in your ignition switch?

[mrsr32]

Difference between pin 45 from ign and the 49 from the relay is about 0.5V.

So If I changed it around the ECU would be about 0.20V diff than the battery.

[GTSBoy]

Well, you could run a new fat power wire over there if you wanna get closer.