further 1.8t problems

[ub7rm]

When you open the door is quite a distinctive hummmm noise, you will know if you hear it or not.

   so is that hummmm noise suppose to be there cuz like u said every time i open my door i can hear it ..... but i hvnt got any error code showing up .....

Thats normal mate, thats what should happen!

[AndyMitton]

anyone know the correct part number/cost for the fuel pump relay? looked on GSF and they list one for like 7 quid and another for 30odd quid

Thanks, Andy

[AndyMitton]

well, here we are again.

had a look on VAGCOM after messing about with my car...same codes as ive had before (fuel trim rich, secondary air leak, pressure drop between turbo and throttle...and a low signal to MAF fault...this may have been that i unplugged the MAF (cant remember if i unplugged the MAF before or after i reset the codes last time...) anyways...

cleaned the throttle body so its gleaming and re-aligned it...all seemed ok...much much smoother idling now

problem is, that its still giving crap fuel economy and the emissions light is bak on....i suspect i will recieve the same error codes from VAGCOM when i plug in tonight....has anyone any light to shed? all the hoses seem to be in good order. fed up...wish i still had my rover!!

Thanks, Andy

[AndyMitton]

...anyone...?

[ub7rm]

So the fuel pump relay didn't make a difference then?  :sad:Does it at least prime every time you open the door now?

I'll need to have a think......

[AndyMitton]

primes most time, yea. but sometimes ther's cars and that driving by so dont hear when i open the door...if it wansn't priming would the effects not be a lot worse?

its been pulling really well recently actually, just the emissions light is on again.

thinking MAF could be on its way out, but not too sure really. cleaning the throttle body out had made a difference though to be fair. just sometimes feels slow n sometimes its brilliant.

Thanks, Andy

[ub7rm]

Its very very frustrating when this happens.  I'm starting to think its your O2 sensor.  MAF problems generally cause lean running not rich whereas generally O2 probs cause rich running.  It would give you exactly the symptoms you describe too.  When my MAF went I wasn't sure if it was the problem or not so when I went to the VW parts dept they agreed that they would take it back if it didn't solve my problem as long as I brought it back in a couple of days.  Maybe yours will too?  Or do you know anyone nearby with a 1.8T (or a 2.0 - same part no iirc) that you could do a swap with?

So what exactly have you done so far to address this problem?

Just a final (and probably stupid) thought but hows your oil level?  If there is too much in there it will cause an emissions problem and will more than likely result in poor performance.

[AndyMitton]

deffo not too much oil. thanks though

the local VW dealers, to be named and shamed are Richard Alexander who are terrible! (wakefield)

so i won't b going there. well ill get it on my VAG COM tonight or tommorrow, and you can address bank 031/032 to check for the o2 sensors functioning

you're right, i MAF would cause lean running! Thanks!

i get a secondary air injection fault, so maybe a pipe's split; maybe i've not looked hard enough?

cleaned throttle body, new temp sensor, checked most hoses, throttle body alignment, new plugs (gapped at 28 thou), new diverter valve (other one was sha**ed)

Thanks mate, Andy

[ub7rm]

Can you hear the secondary air injection pump?  When you start her from cold (ie first start of the day) its quite a distinctive noise, especially with the bonnet open.  Sort of sounds like a hoover.  It should cut out after about 100 seconds and will coincide with your revs dropping.  The SAIS only operates with a cold engine for a very short period of time so should not be causing any performace issues.

Given topher's post and you not hearing the pump priming I would be focusing on that.  If the pump isn't priming (or operating at all) I think its possible that the engine would 'suck' the fuel out of the tank but would suffer from fuel starvation under high load or when going up hills etc etc.  I could also be talking s**t here.

Let us know how you get on with the vag com results.....