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Old 04-08-2013, 03:16 PM   #1
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Default Tuning cranking pulse in 130-170f coolant range

Hey guys, I've been running my Reverant MS2v3 for awhile now (8-9 months). I've gotten most everything tuned to my satisfaction except the warm-ish start after sitting heatsoaked for an hour or two that people report a lot of problems with.

Anything < 110 or so (cold), or > 180 (hot start after sitting for just a few minutes) works pretty well. Starts right up with no issues.

But anything between those ranges takes a long time to start (I can crank for 10-12 seconds, stop, then re-try for another 7-8 seconds before the engine finally "catches"). I've got my IAT placed on the cold side of my intercooler.

One thing I've noticed: When it's having trouble starting in this range, holding the gas pedal approx 40% throttle position seems to help it start right up in just a few cranks. I'm not sure if this means I need to add more fuel (cranking pulsewidth), or more air (PWM cranking duty)? I've tried playing with both, without much success/help to what I've already got.

I've attached what I think are relevant tables and my current tune, if anyone has any suggestions it'd be appreciated!
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Tuning cranking pulse in 130-170f coolant range-screen-shot-2013-04-08-11.07.28-am.jpg   Tuning cranking pulse in 130-170f coolant range-screen-shot-2013-04-08-11.10.14-am.png   Tuning cranking pulse in 130-170f coolant range-screen-shot-2013-04-08-11.12.01-am.png   Tuning cranking pulse in 130-170f coolant range-screen-shot-2013-04-08-11.12.12-am.jpg  
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File Type: msq sjpAlmostAwsesomeTune.msq (95.0 KB, 74 views)
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Old 04-08-2013, 03:21 PM   #2
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Without a log, it looks and sounds like too much fuel.
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Old 04-12-2013, 10:02 AM   #3
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try to start with flood clear (ie, +70% tps in your settings). If it starts, too much fuel was given.
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Old 04-12-2013, 03:37 PM   #4
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Thanks Westfield, I'll give that a shot. I wasn't sure if 50% throttle means more fuel AND air is introduced, or just more air.

I have my wideband hooked up to a power source that cuts during cranking, if I move it to a source that keeps power during cranking will it tell anything useful since the engine won't be firing?
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Old 04-13-2013, 04:22 PM   #5
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Quote:
Originally Posted by SJP0tato View Post
I have my wideband hooked up to a power source that cuts during cranking, if I move it to a source that keeps power during cranking will it tell anything useful since the engine won't be firing?
Don't bother, even if you do this, typically the system drops below 9v during cranking and the unit will reset anyways and run warmup, so you wont get a good AFR read during cranking.

you inject based on the cranking pw% table, so if it starts better with more throttle, then you should reduce the PW at that CLT temp.
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