Lars
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| posted on 1/7/08 at 08:06 PM |
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Megasquirt and fuel pressures query
I have finally got my car started (zetec and MS).
And I have used the data logging to see what's happening.
As I have done no tuning I was not expecting any patterns, but what I did see that MS recorded the fuel pressure of between 14 and 16. (On several
starts)
This is obviously too low. But how can MS measure fuel pressure?
As far as I am aware there are no sensors in the fuel line.
Lars
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MkIndy7
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| posted on 1/7/08 at 08:21 PM |
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There are lots and lots of things that MS can process and log, that either require the correct imput signal to the MS (probably to the development
are) or are calculations based on other measured things.
For example:
I've seen in the Megalog Viewer a BHP guage or logger, No idea how to use it or set it up but from what I understand you can use the rolling
resistance of the car, its weight, and the gear ratio etc and it measures how the car de-celerates.
But as you suspect if you have no fuel pressure sencor anywhere then it can't measure the pressure, and the injectors are more likely to run at
about 30-40 PSI anyway.
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paulf
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| posted on 1/7/08 at 08:21 PM |
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It doesnt record or display fuel pressure, you must be missunderstanding the readings.
What tuning software are you using?
Paul.
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Lars
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| posted on 1/7/08 at 08:32 PM |
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The datalog recording in megatune gives a column called "fuel press".
I assumed that this was fuel pressure, as this showed 42 (looked like 3 bar) a couple of times during cranking, before dropping to 14-16 on
running.
But I cannot see a logical way that it can calculate this.
If you tell me that this is definitely not an accurate measurement then that keeps me happy.
Lars
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matt_claydon
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| posted on 1/7/08 at 08:36 PM |
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MS can measure fuel pressure, but only with a sensor. Without the sensor Megatune will just display nonsense values. There are also several other
readouts in MT that you can display that will read random values without the appropriate sensors and settings.
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Lars
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| posted on 1/7/08 at 08:41 PM |
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I shall ignore this then and start tuning.
Thanks guys
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