Go Back   The 75 and ZT Owners Club Forums > The 75 and ZT Owners Club Forums > Technical Help Forum
Register FAQ Image Gallery Members List Calendar Mark Forums Read
Notices

Reply
 
Thread Tools Display Modes
Old 26th September 2011, 15:22   #1
Rob Bell
Gets stuck in
 
ZT-T CDTi +

Join Date: Nov 2006
Location: London
Posts: 561
Thanks: 7
Thanked 10 Times in 7 Posts
Default CDTi not starting: Cam position Sensor?

Hi Guys,

I love my ZTT I really do - but sometimes it can be a real pain in the...

So yes, this is another "Diesel not starting thread" - of which there have been a few over the years.

The problem on my car is that it failed to start on Saturday, and because I don't routinely keep a can of easy-start in the car, we had to call the AA to get us going again (easy-start did the job).

Since having the injectors rebuilt last year (excessive leak back), the car's performance has been significantly improved, but start up has often required turning the engine over for longer than it ought to - and it may take a few seconds to get going. On Saturday, it decided not to start at all.

I've replaced both the in-tank and underbonnet fuel pumps over the last couple of years (2003 model). And as mentioned, the injectors have been rebuilt due to the unsurprising discovery of excessive leak back.

So the possibilities are:
1. are the injectors still leaking?
2. or is this a new manifestation of yet another common diesel problem, the cam position sensor?

Once running, the engine runs a treat (which wasn't the case before the injectors were sent away). But the key question is how can I tell at home whether this is a cam position sensor problem without handing over the best part of 150 quid to Rimmer Bros for a new one?

Thanks for your help chaps!
Rob Bell is offline   Reply With Quote
Old 26th September 2011, 16:08   #2
FrenchMike
This is my second home
 
FrenchMike's Avatar
 
Rover 75 Saloon

Join Date: Aug 2007
Location: Avignon
Posts: 4,466
Thanks: 94
Thanked 661 Times in 554 Posts
Default

Quote:
Originally Posted by Rob Bell View Post
Hi Guys,

I love my ZTT I really do - but sometimes it can be a real pain in the...

So yes, this is another "Diesel not starting thread" - of which there have been a few over the years.

The problem on my car is that it failed to start on Saturday, and because I don't routinely keep a can of easy-start in the car, we had to call the AA to get us going again (easy-start did the job).

Since having the injectors rebuilt last year (excessive leak back), the car's performance has been significantly improved, but start up has often required turning the engine over for longer than it ought to - and it may take a few seconds to get going. On Saturday, it decided not to start at all.

I've replaced both the in-tank and underbonnet fuel pumps over the last couple of years (2003 model). And as mentioned, the injectors have been rebuilt due to the unsurprising discovery of excessive leak back.

So the possibilities are:
1. are the injectors still leaking?
2. or is this a new manifestation of yet another common diesel problem, the cam position sensor?

Once running, the engine runs a treat (which wasn't the case before the injectors were sent away). But the key question is how can I tell at home whether this is a cam position sensor problem without handing over the best part of 150 quid to Rimmer Bros for a new one?

Thanks for your help chaps!
Hi Bob,

Have an eye here,that could helps:

http://www.the75andztclub.co.uk/foru...ad.php?t=69308

Another tip to test the camsensor:
During cranking you must get around 9 volts on the yellow wire (middle one)

Good luck

Mike

Last edited by FrenchMike; 26th September 2011 at 16:13..
FrenchMike is offline   Reply With Quote
Old 26th September 2011, 16:35   #3
Rob Bell
Gets stuck in
 
ZT-T CDTi +

Join Date: Nov 2006
Location: London
Posts: 561
Thanks: 7
Thanked 10 Times in 7 Posts
Default

Quote:
Originally Posted by FrenchMike View Post
Hi Bob,

Have an eye here,that could helps:

http://www.the75andztclub.co.uk/foru...ad.php?t=69308

Another tip to test the camsensor:
During cranking you must get around 9 volts on the yellow wire (middle one)

Good luck

Mike
Mike, you're a star! I was looking for these links using my wife's Blackberry while waiting for the AA to arrive, but couldn't find them!

Might try the cam sensor spacer trick before buying a new sensor - any recommendations on where to buy? Local branch of Halfrauds presumably? Rimmer Bros don't currently have them in stock
Rob Bell is offline   Reply With Quote
Old 26th September 2011, 17:11   #4
FrenchMike
This is my second home
 
FrenchMike's Avatar
 
Rover 75 Saloon

Join Date: Aug 2007
Location: Avignon
Posts: 4,466
Thanks: 94
Thanked 661 Times in 554 Posts
Default

Quote:
Originally Posted by Rob Bell View Post
Mike, you're a star! I was looking for these links using my wife's Blackberry while waiting for the AA to arrive, but couldn't find them!

Might try the cam sensor spacer trick before buying a new sensor - any recommendations on where to buy? Local branch of Halfrauds presumably? Rimmer Bros don't currently have them in stock
The other old tip is to put the sensor in a fridge for 15 minutes and try.

Mike
FrenchMike is offline   Reply With Quote
Old 26th September 2011, 17:21   #5
Mike Noc
This is my second home
 
Mike Noc's Avatar
 
Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4.

Join Date: Jul 2009
Location: Hampshire
Posts: 11,531
Thanks: 3,470
Thanked 3,119 Times in 2,247 Posts
Default

If the engine starts with Easystart then it isn't a cam sensor fault. Could be a coincidence as by the time the AA man got there the sensor may have cooled down but if it starts again on Easystart then it sounds more like low fuel pressure on the HP side.

Mike

Last edited by Mike Noc; 26th September 2011 at 18:30..
Mike Noc is offline   Reply With Quote
Old 27th September 2011, 17:17   #6
Rob Bell
Gets stuck in
 
ZT-T CDTi +

Join Date: Nov 2006
Location: London
Posts: 561
Thanks: 7
Thanked 10 Times in 7 Posts
Default

Thanks - I'll check the pressure profile as FrenchMike demonstrates on the link, but using the retrospectoscope, the car often is a little harder to start from warm, but then it never really starts that brilliantly from cold either.

It will be properly annoying if it proves to be the injectors being at fault! >
Rob Bell is offline   Reply With Quote
Old 27th September 2011, 18:10   #7
James.uk
Passed Away
 
2002 Pale Blue. Rover 75 CDTi Connoisseur auto. 170K miles

Join Date: Dec 2008
Location: Near the M67.
Posts: 14,509
Thanks: 199
Thanked 585 Times in 397 Posts
Default

I had a similar problem recently, mine turned out to be the HP pump that feeds the common rail..

My pump was putting out 45bar which was enough to run the engine, but it was not enough to get the engine started..

Pump should produce about 150bar apparently...

New pump sorted it..

But do a leakback test on your injectors asap..
...

Last edited by James.uk; 27th September 2011 at 18:13..
James.uk is offline   Reply With Quote
Old 28th September 2011, 12:57   #8
Rob Bell
Gets stuck in
 
ZT-T CDTi +

Join Date: Nov 2006
Location: London
Posts: 561
Thanks: 7
Thanked 10 Times in 7 Posts
Default

:LOL:

Well, having replaced two LP pumps, I guess it would be just my luck if the HP pump is on it's way out.

As much as I love our ZT, it does seem to be having a habit of working its way through ALL the common problems these cars have. I've also had the pleasure of replacing the fan and trinary switch!
Rob Bell is offline   Reply With Quote
Old 28th September 2011, 14:14   #9
BigRuss
Premium Trader
 
BigRuss's Avatar
 
75 CDT Tourer,2.5 Launch Saloon, Omipro MG/Rover (T4)

Join Date: Jul 2007
Location: Liversedge, West Yorkshire
Posts: 5,405
Thanks: 1,105
Thanked 1,340 Times in 661 Posts
Default

If it is the high pressure side of things then chances are that either the pressure regulator on the HP pump is sticking or the micro-pellet filter is blocked.

Good news is that the regulator is available seperately, as is the filter, replacement of either does not require removal of the pump

Russ
__________________


Replacement Key Service
http://https://the75andztclub.co.uk/...d.php?t=244732
Full T4 Testbook diagnostics available.
Diesel ECU repair and replacement.
Options enabled or disabled as required.
Diesel X-Power 135 and 160bhp, Rover 1.8T 150 to 160
MG 160 V6 to 177 upgrades available
P.M. for details.
BigRuss is offline   Reply With Quote
Old 28th September 2011, 15:22   #10
Rob Bell
Gets stuck in
 
ZT-T CDTi +

Join Date: Nov 2006
Location: London
Posts: 561
Thanks: 7
Thanked 10 Times in 7 Posts
Default

Thanks Russ - that's encouraging.

The first thing to do then is to interrogate the fuel pressure line sensor as FrenchMike details. If the HP pump is causing mischief, then presumably the returned voltage will provide an indication of this?
Rob Bell is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 13:28.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright © 2006-2023, The Rover 75 & MG ZT Owners Club Ltd