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Cosworth crank sensor voltage

Old 02-07-2019, 09:00 PM
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Topjoe9
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Default Cosworth crank sensor voltage

I've been carrying out tests on my crank sensor. I've been told I should have at least 2volts at ecu pins 3 and 4 whilst cranking the engine with ecu disconnected.
im getting nothing so presume sensor failure or break in the loom.
Is the test procedure correct or am I doing something wrong?
Thanks for your help.
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Old 04-07-2019, 12:46 PM
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Are you measuring AC voltage?

If so, yes it's faulty.

Martin
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Old 06-07-2019, 01:44 PM
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stevieturbo
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scope it, a multimeter is almost useless.

Voltage will vary with rpm, and could be as low as say 0.5 volts to a few hundred at higher rpm's and will be a waveform. NOT a steady voltage.
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Old 07-07-2019, 12:09 PM
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Thanks for the replies, My problem is my car is running a p8 ecu which is in limp mode. I've now replaced crank,phase, air and water temp sensors, tried another map sensor, set tps and base idle and still have the fault.
Om going to try to reset the ecu again as this may be the problem. When I try to do the reset procedure I don't get the very quick clicks as I'd expect even when being done on a standard chip.
Any ideas on anything else it could be ?
cheers.
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Old 07-07-2019, 12:15 PM
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Rather than doing random shit and throwing needless parts at it....some proper diagnostic procedure might help.

And what is this actual problem...and how are you determining what limp mode might be ?

http://bigturbo.co.uk/
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Old 07-07-2019, 07:35 PM
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I'm determining limp mode as it runs perfectly until exactly 4000 rpm then will not rev past it. I've been diagnosing the wiring and sensors using manuals and guides found on other threads.
the sensors I've replaced along the way have been spares I have which are known to be working.
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Old 07-07-2019, 09:29 PM
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So you've made up a limp mode ?

Check for fault codes, it will be a sensible first step, rather than throwing parts at it. It may be a basic system, but in the absence of anything else, it will be a starting point
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