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tjts1 · 04-18-2011, 04:28 AM

Here is how I tried to optimize injector off overrun on my manual Mercedes using megesquirted efi. The goal was to maximize my ability to coast with engine in gear and injectors turned OFF. Engine braking be damned, that's what the 4 pot calipers are for.

To go into overrun (injectors off):
TPS = 0% open
coolant > 60f
RPM > 1300

Once in overrun:
ERG is turned ON to help equalize the pressure between intake and exhaust

Exit overrun:
RPM < 1100
or
TPS > 0%

This seems to work pretty well for me. The EGR valve makes a big difference in how far I can coast. I was actually kind of surprised. Our other car which runs it's stock engine management will only go into overrun above 2000 rpm and coolant over 160f.

04-18-2011, 04:28 AM	#47 (permalink)
tjts1 Banned Join Date: Feb 2008 Location: california Posts: 1,329 Thanks: 24 Thanked 161 Times in 107 Posts	Here is how I tried to optimize injector off overrun on my manual Mercedes using megesquirted efi. The goal was to maximize my ability to coast with engine in gear and injectors turned OFF. Engine braking be damned, that's what the 4 pot calipers are for. To go into overrun (injectors off): TPS = 0% open coolant > 60f RPM > 1300 Once in overrun: ERG is turned ON to help equalize the pressure between intake and exhaust Exit overrun: RPM < 1100 or TPS > 0% This seems to work pretty well for me. The EGR valve makes a big difference in how far I can coast. I was actually kind of surprised. Our other car which runs it's stock engine management will only go into overrun above 2000 rpm and coolant over 160f. Last edited by tjts1; 04-18-2011 at 04:34 AM..