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Citroen C3 cam vs crank fault engine timing is GOOD
Citroen C3 cam vs crank fault engine timing is GOOD
There is always that one that defies us. Got a 2010 citroen C3 1.6 engine code 5FS (EP6C) chassis VF7SC5FS9AA677179. Presented to us with an intermittent crank no start 2 Fault codes stored P0341 inlet camshaft position sensor out of range/performance & P0366 exhaust camshaft engine power too low (the description is from bosch KTS so more worried about the p codes). The best our information has it is this means the cam timing is off. So on with the scope perform 2 x cam and crank correlation and compare to a known good and yep the inlet cam is definitely retarded and the exhaust cam also but only by one crank tooth or so. Fit new timing chain kit including tensioner and both VVT pulleys. It would start when cold and run forever until the moment you tried a hot start then it would cut injector and primary ignition control and instantly log the two fault codes above. So we went through the combination of swapping VVT solenoids from side to side unplugged plugged in no change at all (plus inlet VVT should advance camshaft not retard it so can pretty much rule that out in one go) swapped sensors side to side and even fitted a genuine bosch sensor to inlet still no change. if you unplug one sensor at a time the computer logs an extra fault code for the correct cam shaft (wiring is not reversed on to wrong sensor). Got an unused spare head with camshafts in to visually compare where cam ring lobes are compared to where problem vehicles are THEY ARE IDENTICAL in every way locking tool included. When the engine is started from cold and stays running the 2 x cam v crank waveform matches known good when the computer starts logging the fault codes and then it will refuse a hot start is when the waveform stops being the same as known good. So i agree with the fault codes 100 per cent the scope shows the cams are out (inlet retarded more than exhaust) and the computer is telling us the cams are out. At this point if you whip the lid off i promise the locking tool will fall onto both cams and crank so the engine is physically in the right place. at that point we have a live cranking waveform showing an out of time engine that will lock up with tool in exact right position the only thing i can think of is oil pressure whilst cranking a hot engine (low oil pressure) so changed oil for correct oil and filter. But still the same. Right now its COLD with the new oil in and a timing tool that falls on but will not start and instantly logging the above fault codes with a live cranking waveform showing an out of time engine. So i have run out of ideas????? I hope you guys have got some to fire at me PLEASE. Thank you for your help in advance 
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- Citroen_C3_2010_Petrol_no start and a start.psdata
- (16.42 MiB) Downloaded 193 times
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- Citroen_C3_2010_Petrol_In cyl WONT START BAD.psdata
- (29.74 MiB) Downloaded 185 times
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- Citroen_C3_2010_Petrol_in cyl cam v crank good and bad.psdata
- (26.43 MiB) Downloaded 181 times
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- Citroen_C3_2010_Petrol_Cold crank no start timing tool falls on 1.psdata
- (4.58 MiB) Downloaded 176 times
Re: Citroen C3 cam vs crank fault engine timing is GOOD
Probably trigger wheels got magnetised? Anything unusual with the start cables from battery to start motor or even at alternator? Aftermarket sensors still on engine?
Re: Citroen C3 cam vs crank fault engine timing is GOOD
In pic attached the peak compression on the left is high and the cam v crank is off then the engine is stopped in the middle and then restarted and it returns to idle with a lower peak compression and a cam v crank that is now good prooving beyond all doubt that the mechanical timing is changing the peak compression and the cam v crank angle. Has to be mechanical to change peak compression cam v crank just backs it up further?
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Re: Citroen C3 cam vs crank fault engine timing is GOOD
Hello.
.
If there are serious errors in the engine management system, the velvetronic system is turned off.
The electronic throttle system is activated.
The engine starts working with discharge in the intake manifold.
That's why there is a difference in compression.
.
Since both phase regulators have already been replaced, it can be assumed that there is not enough oil pressure in the cylinder head.
There may be a leak on the camshaft lugs.
Data on oil pressure - are in the scanner parameters.
If you turn off the oil pressure control valve, you get an inflated pressure relative to the set one - up to the maximum.
This can be used to check the version with oil pressure.
Here is the pressure value when the valve is switched off on a working engine :
.
If there are serious errors in the engine management system, the velvetronic system is turned off.
The electronic throttle system is activated.
The engine starts working with discharge in the intake manifold.
That's why there is a difference in compression.
.
Since both phase regulators have already been replaced, it can be assumed that there is not enough oil pressure in the cylinder head.
There may be a leak on the camshaft lugs.
Data on oil pressure - are in the scanner parameters.
If you turn off the oil pressure control valve, you get an inflated pressure relative to the set one - up to the maximum.
This can be used to check the version with oil pressure.
Here is the pressure value when the valve is switched off on a working engine :
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Re: Citroen C3 cam vs crank fault engine timing is GOOD
Thankyou for the reply but even if the valve tronic system is causing the peak compression to change explain how the cam v crank is changing at exactly the same time as this should have no effect on the cam timing? I can see the Inlet cam v exhaust cam on cam signals shifting to advanced in time and retarded every time the inlet cam does this the peak compression changes? If you download the in cyl cam v crank good and bad and look at all the different peak compression stages and zoom into the cam v crank at that particular stage you can clearly see the Inlet cam is either rerarted in the right place or even on the medium peak compression stage it's even in an advanced position considering the valve tronics should only effect the how far the valve opens it should have zero effect on camshaft position is my thinking? Thankyou in advance
Re: Citroen C3 cam vs crank fault engine timing is GOOD
After starting the engine, a PWM signal appears on the control valve,
that is different from the control PWM = 10%.
When controlling approximately about PWM = 40%, a shift towards late is obtained.
The shaft occupies the same position equal to 110 degrees on the scanner.
But this is subject to the nominal oil pressure through the valve.
that is different from the control PWM = 10%.
When controlling approximately about PWM = 40%, a shift towards late is obtained.
The shaft occupies the same position equal to 110 degrees on the scanner.
But this is subject to the nominal oil pressure through the valve.
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Re: Citroen C3 cam vs crank fault engine timing is GOOD
That doesn't explain why it won't start and logs cam crank correlation faults during a crank no start and can also be seen on oscilloscope whilst cranking an out of time inlet camshaft. The VVT is not operational whilst cranking and I would expect an engine that has no oil in it at all to still fire up but just rattle like hell?
Re: Citroen C3 cam vs crank fault engine timing is GOOD
Just an opinion.
There may be not one, but several malfunctions.
One - is the wrong ratio of crankshaft - camshafts.
This can be argued - based on the errors that are available immediately after starting the engine.
The second - is the lack of engine start.
.
The easiest way to determine this, is to get input-output signals.
Where the input - is the synchronization signals from three sensors.
Output - signals from the coil driver and injectior driver.
There may be not one, but several malfunctions.
One - is the wrong ratio of crankshaft - camshafts.
This can be argued - based on the errors that are available immediately after starting the engine.
The second - is the lack of engine start.
.
The easiest way to determine this, is to get input-output signals.
Where the input - is the synchronization signals from three sensors.
Output - signals from the coil driver and injectior driver.
Last edited by vasek on Fri Jul 29, 2022 8:35 am, edited 1 time in total.
Re: Citroen C3 cam vs crank fault engine timing is GOOD
Here is 5FS, which starts normally.
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Re: Citroen C3 cam vs crank fault engine timing is GOOD
Cam v crank ratio is fine as it has started and run from Cold and restarted whilst cold with no problems and no fault codes. There is only ever 2 fault codes being stored ones mentioned above. If you leave it to power down completely and then try a hot restart you get a little cough as the ECU tries to run the engine then realises the cam is out and cuts inj a primary ign and logs 2 fault codes mentioned above. If you perform all of the above again with the inlet cam sensor unplugged it starts up as ECU cannot make the cam v crank calculations. So I say that something has to be moving around on the engine for 1. The peak compression to change at idle. 2. The cam v crank can clearly be seen moving and 3. The engine ECU fault codes match the scope capture. Unless you can see something in the data I have provided that I am missing?? The million dollar question is WHAT can cause that, that hasn't already been replaced? If you could upload a known good crank v 2 x camshafts on a HOT 5FS engine starting to idle In a downloadable pico file so that I can compare it to our vehicle too that may aid the diagnosis. Thankyou in advance for your help?