Help required......

[GingerMagic]

Hi everyone.

I recently had my clutch/DMF changed by a local garage who have been very good in the past but not a Peugeot specialist ( but conveniently next door to my work... ) and since I got the car back it has seemed a bit hesitant.

The chaps in all fairness put the car back on the ramps to check if anything was amiss and gave it the all clear.

I can only describe the problem as lack of low-down grunt/response. I bought a new MAF as the symptoms were similar and there was an offer at GSF, but the problem hasn't gone away, but I now have a spare MAF

I spent half-hour this lunch time with my vac gauge and I have managed to work out that the vacuum leaving the turbo EV is low, about 200 on the gauge, but the vacuum going in is the normal 700 on the gauge. I have a feeling that the vacuum reading should be 700 on the gauge coming out of the turbo EV to feed the turbo vanes, but I have no way to check unless a fellow Hdi owner can put a vac pipe on their turbo EV to test for me..??

Now, the interesting part is if I unplug the MAP sensor, the vac reading jumps to 500 on the gauge and back down to 200 when I plug it back in again....

So, to summaries, it seems something isn't quite connected as it should be ( although it all looks okay from above ) and the turbo axle isn't fully retracted so the car is running with the vanes partially opened at low revs - so is this something that someone has come across before? It seems something is telling the turbo EV to reduce vacuum...

Just to add my vacuum system is fine, swirl is completely bypassed, no reservoir and no leaks. I have tested several spare EVs and MAP sensors with the same results.

Any help would be appreciated as this problem occurred about a week before my IQ93 was flashed, so I'm unable to fully appreciate its potential...

Kelv.

I have posted this on the Coupe club too....

[Doggy]

Hi Kelv, sorry to hear you have problems.
I don't have access to a vacuum gauge or I'd happily do the comparison for you. Failing that, have you looked at the turbo pressures, (requested and actual), on planet? (You usually get around 1000 +/- 50 for both and a difference of < 30 or so at idle).
Not tried unplugging the MAF, but I would have expected it to read no boost and attempt to correct it by adjusting the turbo, which it sounds like what yours is doing.
The turbo e/v is controlled in a time-proportioned manner - it opens and closes rapidly so as to mimick a true adjustable valve. The pulses will be too fast for your vacuum gauge to register, but the point is you will only ever get the same vacuum at the outlet if the duty cycle is 100%, (or is it 0%? - it'll be one or the other). You can probably get a good impression of whether it's doing what it should by observing the duty cycle via planet, while watching what the gauge tells you.

Not much help I'm afraid, but if you get some numbers from planet, I'll do the same on mine and let you know what I get.

[GingerMagic]

Thanks Eric.

Graham ( Womble ) from the Coupe club works just down the road from me, and he has offered his car for a vacuum comparison. I'll check his outlet ( snigger ) and see what it reads.

I'll also have a butchers at donor cars engine bay to compare leads/connections etc.

[GingerMagic]

I tested Grahams car today, and his vacuum output is the same as mine, so my vacuum isn't the problem.

Back to the drawing board but I will concentrate on the throttle as it isn't as I left it and almost at the end of the coiled bit....

[Doggy]

Regarding the TPS, mine has the spring clip on virtually the last possible slot - nearly as tight as possible - but provided you get 0% with your foot off & 99% with it buried in the carpet, I guess all's well.
Is your clutch switch OK?
Cruise working OK?
I'm assuming you didn't fit the Volkswagen MAP sensor or Vauxhall rail pressure sensor - correct?
Have you checked for a boost leak?

[GingerMagic]

Not yet - I'll have to go back to basics and just check all the things that I recommend other people should check if they have a similar problem.....pffft.

Cruise works okay, standard 406 sensors at the moment.

Vacuum is fine, MAF and MAP are fine, turbo EV is fine so that eliminates quite a bit, I'll check for boost leaks next as the pipes were removed to get the gear box out.

Time to break out PP2000 - its better and easier on my new laptop ( £30 from eBay ) is far quicker than my old one...