My car MY99 went into the local dealer for a service this morning - I had reported the well known problem with hesitation below 3,000rpm, and intermitent clutch judder. On the 'hesitation' I was given two leaflets with an explaination for the hesitation.

The first, from Bryan C Pimm (Group Technical Services Director) states "We have experimented with various techniques in an endeavor to eradicate the phenomenon and acheive customer satisfaction. However, we have been firmly advised by Fuji Heavy Industries that the phenomenon cannot be eradicated, and is a normal characteristic of 99MY/00MY specification models. Where improved performance has been reported, this is invariably attributed to the rectificatin of other conditions previously mis-diagnosed or undetected..

Part of the second leaflet states "At engine speeds of 2,500rpm- 3,000rpm, exhaust gas velocity can be reletively low, and turbo boost pressures accordingly lower. This is caused by the turbine wheel and the impeller wheel in the turbo-charger unit not having attained sufficient rotational speed to create a smooth flow of turbo-charged air pressure into the engine. This causes airflow to pulsate, and produce a sensation of 'unsmoth' combustion.

My words now - Having driven other turbo-charged cars and not experiencing this 'phenomenon' I smell bullsh1t.

I will see tonight if there is any improvement and if they have rectified 'other conditions'

 

Since the small TD04L turbo generates max boost by 3000 rpm its hardly likely to be that, as you say .... since fitting an aftermarket ecu does eradicate the problem conclusions can be drawn I think. Also see my post in RT's thread on the same subject.

 

Bob, this topic keeps coming up, with less than satisfactory results for the people that have the problems ...

In the other thread in general, the suggestion of the "oversensitive" knock sensor was brought up.

Is there any validity in the following ?

Standard ECU uses knock sensor to adjust timing.
With the Unichip setup you still use the standard ECU which uses knock sensor to adjust timing.
Prodrive ECU probably still uses knock sensor to adjust timing.

Link does not use knock sensor to adjust timing ... ? (Is that right ? Do you normally use a "fixed" ignition map with the Link, without 'auto adjustment' at the onset of det ?)

If so, than a Link changes things in 2 ways: MAF sensor & knock sensor. So the answer must be in there somewhere ?