The Dispatch | Expert | Scudo Hub

Mattress

Member

Registered: 2021-11-25

Posts: 1

Delayed turbo pick up.

Hi,
My 2006 Hdi expert appears to have a flat spot, the turbo eventually cuts in from 3rd gear onwards. I have since changed the fuel filter with no change, then changed  oil and filter which has improved performance slightly from what it was however not totally. The engine check light stays on most of the time.
The engine light will go out and turbo works although delayed if van is blasted along dual carriageway. Can anyone advise me with solutions on this issue.
Thanks

JohnDragonMan

Member

From: Derby, East Midlands, UK

Registered: 2020-06-02

Posts: 456

Website

Re: Delayed turbo pick up.

try unplugging the mass airflow sensor. its the little sensor on the pipe coming out of the air box right on top. if you find it all works perfectly normal (besides the EML being lit up) it is that sensor that has failed. they are like £20 on ebay brand new

theres also another sensor that may be failing, that is the boost pressure sensor located on the boost pipe under the airbox/battery tray. you cant miss it, little black pipe going into a large pipe. this small pipe can over time split and cause a boost leak and make the sensor not read right.
these engines are great as you can just keep unplugging things till they start to work right.

they only need 3 sensors to start, and just 2 to sustain a run. the crank position, fuel pressure sensor, and cam position sensor. the cam sensor is only used while cranking the engine over then its not used when its running.

hope this helps!

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- JohnDragonMan
Notice: I have the tendency to void warranties, blow fuses, cause fires, and other fun stuff.
Words of wisdom: Internally rust proof the sills and subframe! both skins!!. There's always user serviceable parts inside. "Oh that shouldn't have happened".
My 2005 Dispatch Camper Project

OAT

Member

From: Borders/Dales

Registered: 2017-01-03

Posts: 1,013

Re: Delayed turbo pick up.

they only need 3 sensors to start, and just 2 to sustain a run. the crank position, fuel pressure sensor, and cam position sensor. the cam sensor is only used while cranking the engine over then its not used when its running.

hope this helps!

That's a big chunk of very useful info in a nutshell there John, cheers.

Why is the cam position sensor required? 

Surely its position is always physically dictated by gearing and it's always in a "known" position in relation to all other shafts?

JohnDragonMan

Member

From: Derby, East Midlands, UK

Registered: 2020-06-02

Posts: 456

Website

Re: Delayed turbo pick up.

its basically like a self test.  if the belt is out a few teeth but not enough to cause interference with valves, it just wont fire the injectors.

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- JohnDragonMan
Notice: I have the tendency to void warranties, blow fuses, cause fires, and other fun stuff.
Words of wisdom: Internally rust proof the sills and subframe! both skins!!. There's always user serviceable parts inside. "Oh that shouldn't have happened".
My 2005 Dispatch Camper Project