RPM blip by itself when starting

**nlscater** · 04-10-2010,09:51 PM

Hi,
I've been searching on here for any signs of similar symptoms as my poorly 1998 1.9TDI 110, but to no avail.
Does anyone have experience of engine revs instantly bliping to 2K then settling back to ~900rpm idle, when starting.
I also seem to be in limp mode all the time now.
Along with a simultaneous failure of my central locking pump its quite dishartening to have my car falling appart around me!
I'll try and get a diagnostic readout, (my audi garage wanted £50, is it possible to do this any cheaper?)
Many thanks
Neal

**bannedbiker** · 05-10-2010,07:19 AM

Have a search around eBay for either a small handheld fault code reader, or a lead to connect your car to your laptop, then download a shareware version of vag.com
I picked my reader up for about £20 and its paid itself off in no time!
I'll find a link to an old thread which had some good advice...

**bannedbiker** · 05-10-2010,07:22 AM

...Somewhere in this thread:
https://www.vwaudiforum.co.uk/forum/s...d.php?t=102960
is links to both handheld readers and laptop leads on eBAY.

**Quattros** · 05-10-2010,07:37 PM

rpm sensor speed sensor? could be giving a spike in its signal hence the jump in rpm. central lock pump does fail, mine failed at @ 95k, replace with used one, and so far so good..

**VAGMAN54** · 05-10-2010,07:52 PM

or possible air in fuel..................

**nlscater** · 05-10-2010,09:17 PM

Hi,
I've put an OBDII scanner on, and it said there where no DTCs. However i am worried that its the correct reader, it has U380 model number on it (not U280). Will this give me an accurate reading, is there any difference? I can't beleive there are no error codes, my airbag light is on and my inspection is warning is on.

On a slightly different note, I took the air mass flow sensor out and went for a drive but there was no difference, still very sluggish, no turbo.

I do hear a slight turbo whistle but certainly not as loud as it used to be. I'm now consistantly in limp mode.

Strategy: (please suggest otherwise if you think this is not right)
If my OBDII reader is not right, I'll get one off ebay and try some more error codes.
I'll try replacing my fuel filter as i've not done that for a few years.

However it is starting to rack up the faults and I'm beggining to consider cutting my losses and getting rid, but that feels like giving up!!

**VAGMAN54** · 05-10-2010,09:24 PM

an eobd code reader will find nothing on your 1998 diesel,that wasnt brought out untill 2004/5 on diesels you need a code read from vcds or another type of code reader basically it needs to read your model and not a generic reader....

**nlscater** · 05-10-2010,09:37 PM

OK, something like a laptop and vagcom cable? What is vcds?

**VAGMAN54** · 06-10-2010,07:01 AM

yes,vcds is the new vag.com or a snap on type scanner.............

**NickPicks** · 06-10-2010,07:51 AM

I thought VCDS stood for Vag Com Diagnostic Software. I presumed that Ross tech were told not to use the word Vag in their product, so abbreviated it (I might be wrong though)

You can get an ebay cable for around £15, and use the shareware version of vag-com 409 or vcds lite. That'll tell you what the fault codes are, then you can post them back here for everyone to advise you about.