406oc.co.uk

Well things had been good with the car for a while now, but in the spirit of Christmas, Aunti Poll has decided to descend for the festive season (Uninvited, I must add ).

I have had a good read through other postings on this subject, but can't quite find one that exactly duplicates my problems, so I shall explain them...
Been 6 months DeFapped and Remapped. Things went well for most of it, but in the last month the following happens;
The EML light comes and goes, limp mode almost never comes into play.
If the EML is out and I accelerate hard or labour the engine up a hill it will come on.
If I accelerate through the gears, 1st, 2nd & 3rd, the car picks up well, until I change into 4th, then it's like the throttle is disconnected and I have to wait for about 7-10 seconds and the power will come back.
On hard acceleration with the EML light on, there is a fair bit of smoke, but none with the EML light off.
The swirl flap is opening correctly at 2100RPM.

I am sure it is a vacuum issue, but the system confuses me a bit, so I would like some advice, if that is what it is.

Here is what PP2000 is telling me;
Engine ECU: Intermitent fault. Turbo pressure signal. Short circuit to positive or open circuit or value to high.
Engine ECU: Intermitent fault. EGR air circuit fault. Air flow higher than recommended.

Would it be the electrovalve on the bulkhead being faulty that is causing this?
I hope someone knows, because I so like this car, but it is sapping my faith at the moment....

On the HDi, turbo pressure is controlled by an electrovalve mounted to the bulkhead which uses vacuum to control the wastegate. A lack of vacuum to the electrovalve will cause the wastegate to remain shut, allowing the turbo overboost and trigger a MEL and maybe even limp mode - so I am sure weak vacuum is causing DTC #1. The solution to this is first to check all your vacuum lines, ensuring there are no cracks/holes in the system. If all the vacuum lines are fine, then I would investigate the electrovalve as these are prone to failure too. Either way, its an easy fix so don't worry too much about it I believe Doggy had the same issue as you did.
With regards to the EGR issue, have you blanked it off or is the system still functional?

I did not blank off the EGR for the reason that the map I had didn't delete that part of the system.

MixMan wrote:I did not blank off the EGR for the reason that the map I had didn't delete that part of the system.

You can temporarily block off the vacuum supply to the EGR to disable it, then see what the car goes like. It will be fine with the map you have on it.

As Benjamin says, the most likely culprit is the turbo solenoid.

I recently replaced all my vacuum hoses with a 3mm silicon hose from eBay - cost less than £5 The 3mm is a tight fit on all the fittings and will eliminate leaks as the culprit.

Well here is a bit of an update....

Still driving round with the EML on, all the symptoms are as before, but here is what I have done;
New Mass Airflow Sensor
New Turbo Electrovalve
Checked all the vac pipes and they all seem to be in good order as far as I can tell.

Here is what PP2000 is telling me;
Engine ECU: Intermitent fault. Turbo pressure signal. Short circuit to positive or open circuit or value to high.
This is the same as it was before the changes.

Ok, I am lost, anyone have any ideas? Pressure is on as tax expires on sunday and the MOT. It's my only car and I need it to get to work.....

If the fault is intermittent, I think its an old fault and PP2000 can clear it. Is everything connected back in?

The EML light may go off on its own accord in a few runs..

It's not intermitent, it's all the time.
Everything is reconnected correctly and PP2000 will clear the faults, but as soon as you put your foot down it returns to the fault.
The EML does go out sometimes, but that only lasts a few moments before it returns.

Is the vac pipe fitted snugly on the turbo? It should be the left-hand EV, front pipe - follow it down with your hand and you should feel it go on to the turbo 'nipple'....

So that sounds like either a duff sensor or the wastegate not opening.
Possibilities:
* sensor
* vacuum supply
* vacuum electrovalve
* wastegate

GM: can you remember if the turbo electrovalve swappable with any of the others? (Some are either open or closed and others can open partially to a requested percentage.) A swap could eliminate the electrovalve.

Hi Richard, yes all three on the bulkhead have the same part number - its only the swirl-flap one that's different.

I checked all the Vac pipes to see they were seated fully, only one I cant reach is the one to the turbo, typical
I have to admit defeat now and put myself in the hands of a dealer and hope they dont rob me to much....
However, while looking around I came across the two air dosers at the front, same part number, but they look different in detail, could this be a cause? At the top one has a yellow painted star drive type thing, the other (lower) just has a hole.

Ok, first off, thanks for the explanation of how to upload a pic

After spending an age looking at the engine and feeling a bit intimidated, I found a diagram of the air system on another post. I then spent a couple of hours with colouring pens and a pencil working out what went where....
Then I went and re-checked all the pipes of the vacuum system and stumbled across this curious thing....
I have a feeling that this lower Doser is defective and causing my problems, as it should block off the warm air supply once the engine is warm and only allow the air from the intercooler through... am I right or wrong?

The vacuum pipe that works the lower doser was VERY loose on mine, the rubber sleeve had swollen because it was oily and just fell off when I touched it.

Mixman, First I would get rid of all of the doser gubin's as explained by Doggy, Gumby & Gingermagic have done this mod too
All have reported good things.

But it does sound too me like you could be having the same problems as smbbob, the 2.2's have variable vane turbo's & these can get
sludged up with time also the actuator for the variable vane part can become faulty.

Apologies if you already did this but when checking the vac pipes I'd suggest removing them and while you're at it fit new. I ended up needlessly swapping the swirl actuator on mine only to discover one of the pipes off the vac pump had a big split in it where the clamp was. It looked fine when on the car and I only spotted it as I was modifying the pipe work as mine has a Nico pipe fitted.

Also I'd reset the EML and get a willing volunteer to run her up to 2100 RPM and watch the swirl actuator to make sure it moves and holds when the revs hit the mark. If the EML pops up thats a big hint at leak and not component failure.

As DDD says if you can remove the dosers it simplifies things greatly, Nico pipes are ideal for this but Doggy has managed it without, the vac reservoir is another potential leak point but I wouldn't recoomend permanant removal until you've lost your dosers and EGR as it keeps vac for your brakes if things go tits up somewhere else in the system.

Before I fixed mine it would accelerate fine as the swirl was only actuating briefly before shifting gear, it was only when I held a gear on a 60+ road at over 2100RPM that it popped up and I got limp mode. Not fun when overtaking and your car slows to 50 in the right hand lane!!!