After an engine stall..do I need to reset MS?

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linzerl
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After an engine stall..do I need to reset MS?

Post by linzerl »

With code 1.5.1, when my engine stalls, is it a requirement to reset the MS (by turning the ignition off and off again..or clicking ECU reset in Engine control) before attempting to crank again?

If I don't reset the MS, I get no PW when cranking (TPS flood isn't triggered and RPM is at cranking rpm). After a reset using either of the methods above..engine happily starts.

Unsure if this is a bug or working as designed.
billr
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Re: After an engine stall..do I need to reset MS?

Post by billr »

No, that need to do a power-down reset is not normal. I think a problem with your wiring is more likely than a FW bug.

PS: :msq:
TurboBob
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Re: After an engine stall..do I need to reset MS?

Post by TurboBob »

why is it stalling? Do you have a log of it?
linzerl
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Re: After an engine stall..do I need to reset MS?

Post by linzerl »

Thanks for looking.
Log and msq attached.

Some more background/feedback.

I'm unsure if a wiring problem would cause MS to calculate a 0ms PW when cranking..
The car stalled once due to my poor driving skills whilst parking it into my garage..and luckily I had my laptop handy. I then noticed a 0ms PW. The car has been MS'd for 7 years ..and runs very well..and generally doesn't stall unless I'm at fault. I have been purposefully stalling the car to investigate the problem.
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billr
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Joined: Sun May 15, 2011 11:41 am
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Re: After an engine stall..do I need to reset MS?

Post by billr »

Your "cranking pulse" is way, way low. Get that more realistic and see if the problem goes away. Did you see the tool-tip in TS that advises cranking pulse should be near 100 when the engine is hot? Yours is 6...
linzerl
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Joined: Fri Jun 24, 2011 11:37 pm

Re: After an engine stall..do I need to reset MS?

Post by linzerl »

Thanks for your help..I do have larger Injectors and higher fuel pressure than normal for this car (Rover V8 engine)..and I have reduced the crankjng PW recently..so I'll up the pw and let you know how I go. Unfortunately early next week is the first chance I will get.
billr
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Joined: Sun May 15, 2011 11:41 am
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Re: After an engine stall..do I need to reset MS?

Post by billr »

The injector flow-rate (size and FP) will not change the cranking PW from "normal" if the req_fuel value has been correctly calculated. Are you saying your injector flow-rate is kind of unknown, they haven't been flowed for rate and DT with your system? If so, I would correct that first! Having the req_fuel incorrect can cause all kinds of extra difficulty in getting your tune sorted out.
linzerl
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Joined: Fri Jun 24, 2011 11:37 pm

Re: After an engine stall..do I need to reset MS?

Post by linzerl »

Injector size are 440cc..and whilst they haven't been flowed, there are the standard Bosch Green 440cc ones.
The car starts on the key hot and cold...and have spent a large amount of time in the cranking pulse area to get it to do so. Whilst the cranking table is below the 100% that's suggested, the battery drain on to tune a high compression V8 and supercharger has an impact on the injector open times..in effect the actual cranking PW aren't that low..and the engine does reliably start.

To recap, the actual problem is a 0ms cranking PW until the MS is reset..then the engine starts normally. I can't see it being a cranking table issue..upping the hot values to the suggested amounts (near 100% of Req Fuel) causes a delayed start with a strong smell of fuel after starting..

Again, I appreciate your help..
TurboBob
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Re: After an engine stall..do I need to reset MS?

Post by TurboBob »

I haven't reviewed the log, but might it be getting stuck in DFCO/overrun fuel cut or some other mode that is forcing a 0 pulsewidth?
jsmcortina
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Re: After an engine stall..do I need to reset MS?

Post by jsmcortina »

Please post a laptop log that includes all data fields, that might show something.

James
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