Lancia Lybra 1.8 No start

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Lancia Lybra 1.8 No start

Postby dimosbmw » Sat Jan 03, 2015 10:54 pm

Hi at all!
I had a call from another workshop where they had a problem with a car.
When i went there they informed me that the car cut out while driving and the driver pressed the clutch pedal while the car was moving and then he released it again (something like jump start with high revs).
They found that the timing belt failed but this was due to the jump start..
So they repair the engine head,valves etc.
But the car won't start.

I pluged in my scanner and i got p0335 crankshaft sensor - no signal
I got a measurment of the crank sensor signal and after some research i realized that the toothed wheel on the crank has in total 6 teeth.

I then get a capture from both crank and cam sensors and i think that it's ok.

Cam vs Crank.psdata
Cam vs Crank waveform
(217.95 KiB) Downloaded 111 times


The problem is that i have no pulse on ignition coils which probably caused by the error code but i have crank sensor signal at the ecu plug (no wiring problem) so i am suspecting the ECU is faulty.

I hope that someone has similar experience with these car.

The car is a Lancia Lybra 1.8. Engine code:839A7000 with Hitachi ECU.
The engine is the same like Fiat punto HGT.

Thanks in advance!
dimosbmw
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Re: Lancia Lybra 1.8 No start

Postby tode » Sun Jan 04, 2015 11:16 am

One oddity in your acquisition are the voltage levels of the camshaft position sensor, the stage down is not zero volts (ground) and the upper part of the signal is about 6 V, or is usually 5V or 12V.
The probes are connected correctly? The power of the sensor is correct? The mass on the sensor is correct?
I think that if the camshaft position sensor must exit 0 / 12V control unit does not recognize the stage, even if the engine should start the same.
greetings
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Re: Lancia Lybra 1.8 No start

Postby sigoaprendiendo » Sun Jan 04, 2015 12:54 pm

I agree with tode about questioning the way probes are connected.
Did you check the signals at computer connector?
A bad ground connection is very likely as well!

I hope we have a happy ending with this issues
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Postby dimosbmw » Sun Jan 04, 2015 5:51 pm

Thanks for your replies!
Actually from some info that i have the cam sensor should give a signal from 5.2V - 5.8V so i think that is normal.
My BNC ground lead was placed directly on battery's negative and the voltage supply to the sensor was measured and found to be ok. Althought the battery was drained from repeated crank attemps and maybe this is the reason why the signal is not 0V but ~0.5V.

I found some info from a Fiat Brava which actually use the same system and i found these:
1.jpg

2.jpg


Maybe the workshop did something wrong with the timing..
I think i need to set the timing again by making a full (360o) rotation of the crankshaft without rotating the cams.

I will try it and i will post back!
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