Vauxhall Zafira 1.9 CDTi Z19 DT 2008 - Hard starting cold or warm, code P0340 - Fixed #
Posted by James Eardley on November 8, 2012, 9:16 pm
Year of Manufacture *: 2008 Engine Size and Code *: 1.9 CDTi Z19 DT ( Optional ) Scanner Used: Modis and Pico ( Optional) Fault Codes: P0340cam position sensor circuit range/performance
Hi guys,
I have got some tunnel vision going on with this car hopefully someone can help give me some direction for tomorrow.
Vehicle was hard starting before the customer went on holiday to near plymouth from Sheffield. They rang me before they went a good few months ago but there was not much I could do in 3 hours before they set off.
While away the vehicle got worse so they took it to a local garage.
One thing led to another an the Cam sensor was replaced.
The customer took the car back because it still was not quite right, the bloke said he didn't work saturday or sunday so he could not help them.
The customer had the old sensor and told me specifically that the mechanic said he didn't need to take the timing belt off to change the part.
The car has been starting for the last two months (not properly) so the customer has put off the repair, as it is now getting worse they have brought it in.
I scanned it yesterday and noticed it did take about 5/6 seconds to start The above code was the only stored code. Cam speed was half the Crank speed.
I cleared the code in case it was old and organised it coming in today.
The same code was back She had drove 16 miles (I checked milage yesterday)
I have cleared the code again today and it hasn't come back during testing.
It is still hard/rough to start today but drives perfect otherwise.
this capture is BLUE = cam sig @ ECU RED = Crank sig @ ECU GREEN = cyl 1 injector current GOLD = FRPS @ ECU
Cranking speed averages around 200rpm, 250rpm with booster, is this in spec?
3 injection events are missing just before it starts, 5 seem to be missing altogether.
Cam and Crank signals are present and correct and are staying in sync (correct or not).
I am assuming the sync is correct due to the timing being correct, Has anybody got a known good?
Fuel pressure seems to be efficient throughout all my captures.
The car took 6 seconds to start in this capture.
I have checked leak off which, the fuel took about 35 seconds to reach my bottles down about a foot of pipe from idle to 2500rpm during the test. Compared to my usual results from other cars this seems very respectable to me.
Also there is no apparent problems with fuel pressure being generated or controlled in the captures.
I have physically checked the engine timing with the crank pulley timing tool and the cam timing marks as I didn't believe the Cam sensor could be fitted without disturbing the belt.
There were some big dirty paint marks all over the pulleys so I thought I was on to a winner but the timing was bang on
I dont want to over look anything, so, The timing tool I borrowed was not in a labelled box, but the tech knew it was for vaux CDTi diesel, according to Franklin brocure lists the same tool for 8v and 16v?
I am thinking I may have a dodgy starter motor problem, I have had problems like this before, where the engine has appeared to turn over quick enough but struggle to start, but it has always (for me) been accompanied with some 'noises' from the starter. In heindsight I should have took some data
This is the capture from the battery and starter during a rough start,
It took 4 seconds for the car to start in this capture.
I am not sure how clear it will be in the picture, but I am concerned with the starter solenoid curren drawing 85amps before the motor current kicks in.
What do you think?
Could I be overlooking anythink simple in my end of week 'blindness', other than the glow plugs
I know the starter scienario does not really tie in with the P0340 but is it possible I have got two problems and the cam signal is dropping out under different conditions and throwing me a red herring?
Did you remove the bottom toothed pulley and checked the keyway?
I did a saab a while back which had that fault, the bolt had a left handed thread. It had a L on the head. The vaux tech said it wasn't so double check. hth.
I didnt check that but I will cheers It would tie in with the fault too
I have got a known good capture for Z19 DTH 16v and the sync is different but not by much.
Does anybody know if they are the same sync?
I have got a 2005 Saab TiD diesel coming in tomorrow morning for alternater testing, hopefully it will be the 8v. The customer is waiting but I think it would be rude not to scope the Cam and Crank while I am at it
James, Does the car start promptly from a bump start? Might prove or disprove the starter motor theory (I had this with an Avensis D4D last year where a new starter motor fixed it). Trying to see on your scope trace if the fuel rail pressure is coming up smartly (the screen res on the laptop I'm using is lower than yours so the trace runs off the screen for me). Shaun.
I will try tomorrow I suspect it probably will do.
'Trying to see on your scope trace if the fuel rail pressure is coming up smartly (the screen res on the laptop I'm using is lower than yours so the trace runs off the screen for me).'
Does this help?
I am looking at the exciter wire current trace now and I think I can make out bad solenoid contacts possibly causing some problems.
I am going to go into work early tomorrow and scope some other starter motors on some diesels we have got in at the moment May shed some light
as been said above bottom belt pulley shears and lets pulley move causing starting problems timing will still line up with tools new pulley and revised tightening torque
Thanks for sharing those captures, I have been trying to add a big thumbs up 'smiley' to my post to thankyou but don't know how
I felt confident I may have 2 faults and moved away from a mechanical or electrical timing issue causing my hard start.
As there were no obvious abnormalities in my other tests
I persued the starter and cranking speed.
I took the starter off and tested it and found bad brush contact effecting my cranking speed
I tested the old and new starter in the vice with the booster pack and measured the current via the Booster neg cable here are the captures.
ZOOMED
I have fitted the new starter and the car now starts on the button the longest start I have captured is 1.8 seconds
The customer was reluctant to pay me to take the timing belt off and check the Crank pulley key way and I warned them that the clutch or flywheel may have caused the failed starter.
I don't know if the P0340 code was caused by the uneven cranking speed or if something is failing under different conditions, I service and MOT this car so I will see if the code is present when I next see it.
Does anybody think the 1 degree or 790us sync difference could cause the P0340 code? Or Could it be that the cam fall needs to be seen in the cranks missing tooth rising edge?
Thanks again James
Fixed #
Posted by James Eardley on November 23, 2012, 10:51 pm, in reply to "Fixed #" Message modified by board administrator November 27, 2012, 2:54 pm
Hi guys
I had this vehicle back in today.
The customer said the EML light was on permenantly and starting the vehicle was even harder to start than the previous repair.
When the customer turned up I scanned the car and P0340 was present. I asked her under what conditions did the light come on. She admitted it came on directly after a hard/violent stall.
on November 8, 2012, 10:11 pm, in reply to "
