Need to get educated on Holley HP EFI
Hello! First off, I have reviewed several posts, but I am just not for sure what it is that I am looking for! So, here is what I have...
LQ4
L92 Heads
TFS 30602003 Cam
Truck Intake Manifold
90mm Throttle Body
Headers
TKO 600
Holley HP EFI
Base tune was the 480hp LS2 off of the global
If you need more specific info, let me know and I will get it.
The problem... Will not idle after any kind of throttle. We can get it to idle well at 1050 RPM, starts easy and the throttle response is very good. Unfortunately, after any kind of acceleration/throttle it goes right by idle RPM and dies. I am not sure what I am chasing down...I have read so much about TPS, IAC and air/fuel ratio that my head is spinning! It's so close to being driveable, but I just don't know enough about the EFI/ECU/LSx world. Please let me know what info you need and thanks in advance for any help you can provide!
Matt
Need to get educated on Holley HP EFI
What is your IAC hold position and the associated ramp decay time? Also, don't put too large of a number in the "rpm above idle to resume idle control" or that can cause a problem. Lastly, what is your IAC positron % at idle?
Thanks!
Need to get educated on Holley HP EFI
Mine has a 25% hold with a 6 second ramp decay time. Just be careful that your hold position doesn't result in an RPM that exceeds your "RPM above idle to begin ramp" or your idle speed can hang up high.
Also, I like to keep a low number in the "RPM above idle to resume idle control" because this is the RPM at which the ramp ends, and if that point is substantially above the idle speed the idle will rapidly fall to (and often passed) your target idle speed.
Need to get educated on Holley HP EFI
For starters, raise the "rpm above idle to start ramp" to its maximum setting then lower the hold position until the idle doesn't hang up high. You can check the IAC position at the resulting rpm to verify where the hold position should be.
In other words if the "rpm above idle to start ramp" is 1,000 and target idle speed is 800... Then go to your idle speed chart and temporarily bring the target idle to 1800 and see what the IAC position % is... Your IAC Hold Position will need to be less than that % for your idle to return.
Once you've got it working and understand the relationships you can fine tune for preference.
Need to get educated on Holley HP EFI
If your IAC is about 7% to 10% at idle then you should be set with the physical adjustments, the rest can be done in the computer. Make sure to do the TPS auto set if you do adjust the throttle.
I agree with the previous post, Danny Cabral is very helpful on the Holley forum.