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Re: 1.9 dCi No Boost
Just as an update to this, I have found and fixed the problem!!
From reading other threads, i worked out that there was no boost sometimes due to the waste gate either being stuck open or the control solenoid being stuck.
So i removed the vacuum pipe from the solenoid to the waste gate. a good suck on the end of it proved that there where no leaks and the diaphragm could be heard lifting the valve and re-seating it.
The solenoid was was not open circuit electrically and was not blocked, by the blow and suck test again. This lead me think what tells the solenoid to move.
I looked at the boost pressure sensor located on the pipe from inter-cooler to inlet manifold. took out the sensor cleaned and replaced, still same problem. I then removed the wiring to this sensor from the plastic conduit and found one of the wires to be broken. Soldered them back together and problem went away!!!!!!!!
This has been caused by the age of he cabling and the heating effect of the engine, the heat has stressed the cable insulation and made it stiff and brittle, the heating effect has also slightly tempered the copper through the constant heating and cooling.
I guess if you get told that a sensor is playing up either by a fault code or mechanic, you should also check the wires to the sensor for signs of ageing.
Currently in benmini's garage:
2001 Renault Laguna II 1.9dCi Sport Tourer