Stalls down hill

[maych87]

I have a aircooled porsche 911. I am in the process of setting everything up in tunerstudio. My current problem is when I am coming down a hill and engage the clutch the engine stalls. There are a couple variables. 1. it does not happen every time i go down a hill, maybe 50% of the time. 2. it may have something to do with my oil cooler fan turning on, the fan is not controlled by the megasquirt. It turns on at a certain oil temp and is controlled by another computer in the car. I have not been able to confirm if it only stalls when the fan is on. Attached is my msq and the datalog of it stalling, look at the very end. If someone could help me figure this out that would be great.

[billr]

When you say "engage the clutch", do you mean pushing down the clutch pedal and disengaging the engine from the transmission?

It seems to me that your over-run fuel cut needs to be tuned, so that fuel comes back on a bit before where you would normally be pushing in the clutch pedal. I would turn off the over-run fuel cut to confirm that is the problem. If so, then we know to focus on that.

[maych87]

When you say "engage the clutch", do you mean pushing down the clutch pedal and disengaging the engine from the transmission?

It seems to me that your over-run fuel cut needs to be tuned, so that fuel comes back on a bit before where you would normally be pushing in the clutch pedal. I would turn off the over-run fuel cut to confirm that is the problem. If so, then we know to focus on that.

When I say engage the clutch I do mean pushing the pedal down to the floor.

When I turn off the over run, am I looking for the problem to get worse to confirm it is an over run issue. If there is no change do we assume it is something else that needs further investigation?


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[billr]

No, I would expect the problem to be lessened, or even go away, if the over-run cut is off.

[turbo conversion]

For some reason I can't open your msq so I can't see any of your settings.

I do see in the log at counter 36.915s to the end afr is 19.8 and IACV duty is at 38.4 to 52.5 so the valve is not closed when it dies.

I agree with billr, I think it is fuel related because of the afr when it dies.

David

EDIT: word

[billr]

Just to confirm, both the MSQ and MSL open fine for me.

[turbo conversion]

Tried again, this is what I get and this is not the first time.

David

[maych87]

Sorry for not replying earlier. I just tested it out today. But upon checking somehow i did not actually turn my over run off. So the bellow datalogs and msq are with my over run still on. I will let you know what happens when I turn it off.

[maych87]

No, I would expect the problem to be lessened, or even go away, if the over-run cut is off.

I finally had a chance to turn over run off and there was no change. It still does the same thing down hills. Seems to be worse when decelerating slowly from above 2000 rpm. When I press the clutch to the floor, rpm falls past idle target to 0 rpm


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