idle timing with Holley HP efi
 

Engine is 1400hp procharged Gen7 sitting in a nordic heat Spinning Max 5 34P, the problem I am having is putting it in gear and it stalling........
I watch the idle bubble drop to new fuel cells and it gets rich and stalls.

I am thinking i need to lean those areas out so it doesnt stall. It idles at an afr of 13.2.

I am using timing control for idle,


Anyone have this problem?
https://cimg3.ibsrv.net/gimg/www.off...f35c66ebf.jpeg

I'm not running EFI, but I am using timing for idle control. I have found that by ramping up the timing below your idle set point it works much better than just idle control alone. I ramp up to 36 degrees by the time it gets down to 500rpm plus idle control it works perfect.

Can't you set timing to 30* for 1500 RPM and below? (just for reference)

are you guys running larger cams?

I assume the IAC is still in play? and responding quickly to the controller commands, or with the Procharger has the IAC been replaced with another source for Idle air control?

Just a thought not knowing the details of your engine management setup.

I tuned my 502 with Holley EFI last summer. You can get away from that problem easy. Are your idle timing near 10*? If you have more idle timing, retard it near 10 so you can screw idle air little up. Then watch what route MAP value go on chart when engine stalls and make agressive timing advance to those points, I use 25*. Take ignition controlled idle off from basic ignition setup, it doesn't work on my engine. It have to done straight to ignition chart.
After that tune fuel map right, if you have O2 sensor connected it's easy to adjust AFR to somewhere 12.5-13 when idling on gear, 14 is ok on neutral.

Hope you get some help.

OK yeah that was what i was told. I need to bump timing UP on those cells then look at fuel. I
Are you using timing for idle control? ASM told me to throw out in the entire area 15-18 degrees then timing idle control has a better chance

I do use the IAC i had it on slow but seems best idle is medium or fast

Perfect, I run about 11lbs of boost and a 11.1 to 1 comp motor, race fuel etc. if i run a small prop i never have an issue but the 34 Max5 drives me insane. I also have to take off with tabs all the way down and speed at idle is 6-7mph.....

I don't use idle spark (ingnition controlled idle) it not work with my long duration cam.
My engine is 502 mag efi, that engine iac is so slow that it not help nothing. Late idle timing make engine idle slow, so you put more basic idle air in and engine idle good. When on gear, advanced timing with little bit more air gives more power to idle on gear

I've found that the surge is not always a result of timing that a lot of time is results from the cells being too rich or too lean above or below the target idle speed. Basiclly when the engine senses a change in MAP it will go lean or rich and then you get the surge. The timing can fix it but the real problem is in the big differences in the tables above and below. You can see this when you're in live mode and the green dot is moving all over the place while it's surging. Once you smooth those tables it usually gets better. Takes a lot of patience sometimes.