Jerky running
 

Hi Everyone, problem with my 2003 Rover 75 1.8T Tourer. The problem started about a month ago with the car cutting out at 3000rpm which then recovered when accelerator lifted and revs fell below 3000. For a period afterwards when excellerating hard the car would cut out, again recovering after accelerator lifted off. Now I have a 'Jerky' ride experience after initial excelleration. Any Ideas please. Regards Ken

How'do Ken sounds like a failing Boost Control Solenoid (attached to the side of the Airfilter Box)- check the Vac hoses connecting to the Solenoid are Connected and intact.


It's possible to bypass the Boost Control if a new Solenoid is required ;)


if i get a chance i'll post a pic or two.




Paul.

Jerky running
 

Hi Paul, any help you can give me, photographs etc, would be most appreciated. Regards Ken

How'do Ken,

I will need to fire up my old laptop to retrieve some images i Have - I had a look on here and all the images from my previous posts r.e this issue are gone - and i don't have any useful images of this area on the laptop i'm using currently :duh:

rather frustrating as I know this issue makes the Car horrible to drive - dangerous even - Good news is, if it is the Boost Control Solenoid then it's easy to confirm and rectify and relatively inexpensive (no more than £40)



You will have to remove the Air filter Housing -

Unclip the Boost Solenoid (circled in the attached image) from the Air Filter Housing, unscrew the Jubilee Clamp securing the Inlet Air Duct, remove the 2 securing screws to the Back of the Cover.

remove the lid and Air Filter.

the Base of the Air Filter Housing will release with a Pull Up and Towards the front of the Car - may take one or 2 attempts (it's secured with 2 rubber bush mounts)

this will allow better access to the Turbo.


check the Vacuum Hose connections are secure at the Turbo - if these have come adrift the Solenoid can't function - and you'd be lucky re-connection should cure the issue.

also check hose connections are on the correct ports - I'll find the image i have showing correct connection and post asap ;)


If the Vac Hoses are connected -

Remove the hoses from the Turbo and the Boost Solenoid - including the small Vac Hose that runs from the Solenoid to the Air Inlet Duct. (use electrical tape to temporarily seal the port on the Inlet Duct after removing the Small Vac Hose)

Connecting the 2 Ports on the Turbo using the Small Vac Hose will bypass the Electronc Boost Control Solenoid - and allow the Turbo to dump excess Boost Via the Wastegate :cool:

this will allow the Car to run at Wastegate Boost Pressure - put the Air Filter Housing etc back and go for a test run - if the issue has Gone you will need a new PierBurg Electronic Boost Control Solenoid and it may be worth replacing the Vac Hoses with Silicon Hose.

it will be fine to run the Car with the Wastegate "Hardwired" the only drawback is a bit less Boost Pressure.


[IMG]https://i.postimg.cc/Y49Rw0tS/Boost-...l-Solenoid.jpg[/IMG]



hope that makes some sense :D - i'll have a look tonight for some better images.



Paul.

Found some pics - not the best quality - hopefully they're clear enough :}


Removing the Air Filter Housing should allow access to the Turbo Vacuum Hose Connections.

[IMG]https://i.postimg.cc/w77ZJD39/2015-11-12-11-25-06.jpg https://i.postimg.cc/jCJhPD5P/2015-11-12-11-25-11.jpg[/IMG]

You should see something like this.

[IMG]https://i.postimg.cc/XrxK4FHS/2015-11-12-11-24-55.jpg[/IMG]


Use this small Vacuum Hose (Circled)

[IMG]https://i.postimg.cc/3kLGPhN3/2015-12-08-15-15-17.jpg[/IMG]


and connect the 2 ports on the Turbo - this will allow the Wastegate to control the Boost Pressure and eliminate OverBoost and Fuel Cut/Shut off.

[IMG]https://i.postimg.cc/wyNsysVB/2015-12-08-14-59-02.jpg https://i.postimg.cc/CnHBJT9T/2015-12-08-14-59-14.jpg[/IMG]


this is a sure way to diagnose and confirm if it's a Boost Control Issue :}


Correct Vacuum Hose Connections.

[IMG]https://i.postimg.cc/dh0kRfBp/boost-Vac-hoses.jpg[/IMG]


Old and New Electronic Boost Control Solenoids.

[IMG]https://i.postimg.cc/Y4c5tjrM/2015-12-08-15-06-05.jpg[/IMG]




hope this makes sense :shrug: i'm not great at explaining things :D




Paul.

Jerky running
 

Hi Paul, thank you very much, most helpful. I will try to carry out your instructions. Regards Ken

Jerky running
 

Hi Paul, the rubber connector on the yellow pipe which goes to the Turbo was worn and fitted badly eventually falling off which improved the running. Chris from Fareham found it and fixed it, you are both Stars, thank you both very much. Regards Ken

:cool: Best Case Scenario a nice easy inexpensive fix - for what initially feels like a major (expensive) issue :}



Paul.

Jerky running
 

Hi Paul, symptoms came back soon after replacing pipe and the problem pipe rubber connector started to come away again. So I changed the Solenoid, now car is fine. It seems the Solenoid was permanently shut causing back pressure on the pipe making it move away from it's connection on the Turbo. Well I learnt a lot.Hopefully my experience may help others. Regards Ken

the Pierburg Boost Control Solenoid failure is common - I've replaced mine a couple of times - it's an easy fix so doesn't concern me too much - this last unit has been fine :}



another issue which could cause the same symptoms would be a stuck/seized Wastegate - this can be tested with a pump connected to the Vacuum Hose (it may be more difficult with Original Vac Hoses, I have Silicon) - remove the yellow hose (on the diagram) from the Boost Control Solenoid, connect a suitable Pump to the Hose and pressurise - the Wastegate Actuator should be seen moving behind the Exhaust Manifold.

[IMG]https://i.postimg.cc/dh0kRfBp/boost-Vac-hoses.jpg[/IMG]


Paul.