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Old 03-08-2010, 10:09 PM   #1
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Default Bad MAP sensor, wiring, vac line or electrical noise?

Don't know what's causing this but it is messing up my mojo. I get very short spikes in the MAP signal on my Adaptronic. Keep in mind the logging rate is probably too slow to show how high the spike really goes. I'm guessing atmospheric (101kPa). All I can feel when it happens is a hiccup from the pretty obvious changes in fuel and ignition and everything else that keys off the MAP.

Sadly I haven't had a chance to check the obvious stuff but I guess I could do that...

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Old 03-08-2010, 10:39 PM   #2
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Is it one data sample wide?
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Old 03-09-2010, 12:29 AM   #3
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basically. resolution down to about 300ms
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Old 03-09-2010, 10:21 PM   #4
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nobody has any ideas or nothin?

I only notice it in cruise FWIW.
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Old 03-10-2010, 01:50 AM   #5
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Any dampening in the VAC line?
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Old 03-10-2010, 12:41 PM   #6
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dampness or damping?

I'm going to yank it all out and check it this weekend I guess.
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Old 03-10-2010, 12:59 PM   #7
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If you lack damping in the vac line you should see periodic noise in it when you raise the time resolution to max.
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Old 03-21-2010, 06:46 PM   #8
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UPDATE. Still doing the weird spikey thing.

Ive swapped in a megasquirt style map sensor (along with its RC circuit) like this:


For reference, the vac line is long, like 3 feet. There is no "damping" other than compressibility of air, but I can't imagine it'd do something like that.
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