2.0 DTi limp mode.

[Ken Edmonds]

As I mentioned in my introduction, I've got a late 2002 Astra 2.0 DTi. I understand it has effectively a Vectra C engine which is why I'm here.
I bought it knowing it was running in limp mode. That's not as daft as it seems, although I'm beginning to wonder, as I paid comfortably under £2000 for it.

I bought an interface for my laptop and Vauxcheck from Gendan. Error codes were P0100 and P0400, MAF and EGR. I replaced the MAF and cleaned out the EGR, absolutely no difference and the same error codes. I was reluctant to replace the EGR, largely because of the price but also for some unknown reason I had a feeling it was't faulty. As it turns out I was right but I'll get to that.

I bought a vacuum gauge, checked the pump output then plumbed it into the system. No problems.

Next I took the inlet manifold off to de-gunge it. It wasn't too bad and must have been done before. When I came to refit the upper manifold I noticed a few nicks out of the lower face which I cleaned up with wet & dry on a lump of steel bar. The upper face had big chunks out of it which I built it up with chemical metal as a stopgap until I got another manifold. There were a few nicks on the EGR face too but that cleaned up OK.
Cleared the codes, started up and 30 seconds later - EML. Just EGR this time, no MAF.

Beginning to despair I bought an upper inlet manifold from a scrappy and a brand new EGR.

Still no difference, if anything it's worse, The throttle pedal has absolutely no effect until it's been running for 30 seconds or so then it will rev to 1500. After a bit longer it will go to 1900 and longer still to 2900. Then the EML goes out, the turbo cuts in and it revs to about 3500. As soon as I put load on the EML comes back on and it's in limp mode again. Before all the "fixes" it would rev to 1900 immediately and the rest as before.

I've run out of ideas and everything that's been suggested hasn't helped yet. Are there any geniuses around?

Sorry for such a long screed as my first proper post.

[brifen]

All these different code readers are fine and do a relatively good job but none quite as good as Tech2 IMO.

Do you know anybody/garage with Tech2 and have the car diagnosed properly? It may just be worth while.

The only thing you've not really mentioned is the boost sensor, have you cleaned that? Alternatively i'd get the old volt/amp meter out and check the electrics to the aforementioned sensors. Also check out the MAF Sensor (again) and check airfilter too. Airflow or lack of it can cause all sorts of probs. Was your new MAF a Brand New Part or a scrap yard pick up??

Bri.

[Ken Edmonds]

Thanks for the response.

I know of a mobile sparks with what I believe is Tech2 but he's not local so I haven't got a price from him yet. The car's SORNed and hasn't got an MOT so it can't go anywhere.

I cleaned the boost pressure sensor with carb cleaner while I was de-clagging the inlet manifold. The air filter's new, as is the fuel filter. The MAF is/was a new pattern part but since I fixed the leaking manifold it hasn't complained about that so the original one is back on now. I also tried it with the pipe to the MAF disconnected to be sure there wasn't a blockage in the air filter box/induction pipe anywhere.