General Tuning/ECU question
Thread Starter
Teching In
Joined: May 2014
Posts: 39
Likes: 0
General Tuning/ECU question Hey all...
I have a question for anyone who would like to tackle it. I am running a megasquirt 3 ECU in my ls swapped 300zx. Since day one, it has been easy to make the car run good everywhere except idle.
This is my first car where I have had the ability to tune the car myself, and I understand the basics of fuel/load/spark, and have it running great for cruising, WOT, etc.
Here's the problem. Anytime that there is a heavy electrical load on the system, the idle oscillates like mad. I can put enough timing in it to make it idle (like 38 degrees) under heavy load, but then I can't make it idle less than 1500 rpm.
Another really weird thing about this ECU. I am using FAST/Bosch white giant injectors Most things I have read said that this injector will function best with a dead time of between .95 and 1.1 ms. I have to back the dead time all the way down to.465 ms to make it run right at idle. As I increase the dead time, the oscillation will occur even when the fans/headlights are not on.
Can someone try to explain to me and my electronically challenged mind what would cause me to have to run so little dead time to make it fuel correctly?
I suspect that the injector drivers are weak, or somehow vary greatly from what is in a stock ECU, or some of the other more popular choices out there.
Thanks.
I have a question for anyone who would like to tackle it. I am running a megasquirt 3 ECU in my ls swapped 300zx. Since day one, it has been easy to make the car run good everywhere except idle.
This is my first car where I have had the ability to tune the car myself, and I understand the basics of fuel/load/spark, and have it running great for cruising, WOT, etc.
Here's the problem. Anytime that there is a heavy electrical load on the system, the idle oscillates like mad. I can put enough timing in it to make it idle (like 38 degrees) under heavy load, but then I can't make it idle less than 1500 rpm.
Another really weird thing about this ECU. I am using FAST/Bosch white giant injectors Most things I have read said that this injector will function best with a dead time of between .95 and 1.1 ms. I have to back the dead time all the way down to.465 ms to make it run right at idle. As I increase the dead time, the oscillation will occur even when the fans/headlights are not on.
Can someone try to explain to me and my electronically challenged mind what would cause me to have to run so little dead time to make it fuel correctly?
I suspect that the injector drivers are weak, or somehow vary greatly from what is in a stock ECU, or some of the other more popular choices out there.
Thanks.
