I’ve been hunting down the reason for my “dead” and irrepeatable throttle stabs. Sometimes at a certain RPM, the engine was crisp, and sometimes it would just bog and lower RPM.
I found out that it is my Overrun Strategy, that when I let off the throttle, is it isn’t in the idle RPM range, then it goes into the overrun strategy (which was slightly negative, and therefore the ignition timing stabilizing at -3º value once I was completely off the throttle.
I suppose an easy solution here would be a timer, to remove ignition only during X seconds. How is everyone else getting around this? I could disable the overrun strategy but I actually like the little pops.
Peugeot 106 rallye 1.6 8v
40 mm ITB’s
16v injectors
catcam 645
60 mm exhaust system
Post your project file. This looks like normal behaviour to me, you are in overrun constantly as you have come off throttle, but you shouldn’t need to cut so much ignition
Seems like I can’t share my project file as I can only save it as .emu3 and that can’t be shared here, I am running a classic.
I had initially tried the ignition angle table at 0º everywhere and received a more or less same pop all over my RPM range, so I delayed it into lower negative numbers. I see that this must be a mistake on my part. I have now raised these values into this
With overrun enabled, the overrun ignition table forces the ignition to a fixed value whenever I lift off the throttle. When I then reopen the throttle, the ignition has to ramp back up to the normal ignition table, which causes a significant delay in torque and a bog during the initial throttle stab. If I disable overrun, throttle response is perfect, but I lose fuel cut. I therefore need overrun to provide fuel cut without its ignition strategy compromising immediate throttle response. The difficulty is finding an overrun ignition strategy that works across a wide range of RPM/load without causing a timing-induced bog when the throttle is reopened.
Apparently new users can’t upload attachments… -.-
If you don’t want huge timing cuts when in overrun, your overrun ignition table should mirror your 0% tps base ignition table. E.g. 47.5 degrees at 8000rpm, 45.5 at 7000, etc… Or drop it down a few degrees from base. That said, I can’t remember if the table lets you go above 30 degrees.
What is the goal with the fuel cut? -70% fuel isn’t enough to combust, so it’ll just be flowing through and either igniting in the exhaust or igniting sporadically.
So tried these new settings, and now I’ve unblocked a new feeling, deep bogging whilst in gear.
So as soon as I prod the throttle whilst in gear, the engine bogs and then starts to pick up, here’s an exerpt of these bogging events, note where TPS is activated and RPM doesn’t meaningfully go anywhere.
Stopped at the side of the road, disabled overrun, and all was fine…
According ur statement ur main claim is bad throttle response after overrun. This is controlled by ignition exit rate. Set it to max value and u have a sharp response. But u need also to set fuel enrichment correctly after exit. I assume u have bad transient fueling after overrun exit. So increase those values. I think ur main issue is not ignition. Fix fueling first and then play with ignition.
