still got starting troubles (sorry for the essay)

[ub7rm]

I would try the MAF first, the only reason being that you can return it if its not the problem (best to make sure with the guys in the parts dept first though!) whereas you cant with the O2 sensor.  That said MAF problems tend to cause lean running and O2 sensor probs tend to cause rich running, not an exact science though.  So I would therefore say that in the end its most likely to be the O2 sensor causing rich running and sooting up your TB.  Obviously you'll need to clean the TB as soon as you replace any of these sensors otherwisw you're not going to see any benefit.

[Chris 'N' Jen]

Cheers for the info mate.

great help.

Ill let you know what happens when i get it done.

 

[Chris 'N' Jen]

can anyone explain this?

Due to starting problems iv been trying different ways of starting up on a morn. If i turn the key untill the ignition lights come on and go off, instead of banging the key straight round. then try to start it, its starts a lot easier and doesnt stall straight away. It by no means starts perfectly though.

cheers 

 

[ub7rm]

Have you looked into the fuel pump / fuel filter?  Could be a fuel starvation issue?

[Chris 'N' Jen]

Fuel filter has been changed.

If it was the pump wouldnt it happen when its hot too?

Thanks mate

[ub7rm]

Very true, I was thinking that it wasn't a total starvation just reduced flow / pressure somehow and the cold starting prob was maybe because it takes a bit more fuel to start from cold and a bit more time to get the fuel through from the fuel tank if its been sitting a while.  If you're saying starting it diesel style is a bit easier it might be because you are giving the fuel pump a bit more of a chance to prime / let the fuel come through the lines.

I'm wildly speculating at this point!

[Chris 'N' Jen]

i know what your saying mate.

do you still think could be one of the afore mentioned sensors or do i have to bite the bullet and take it to a vw specialist.

Not lookers at darlington this time.

[ub7rm]

If it were me:

1) Run some fuel cleaner through and give her some beans 

2) Clean out the throttle body, if its dirty again you know this is at least part of the problem.  If that makes a difference to the starting habits of the car then you've got a good lead - it verifys that the tb clean that happened before wasn't just a fluke and that it wasn't the result of something else like a dodgy wire knocked back into place temporarily.

3) IF this eases the starting problem, replace the MAF & clean TB again.  See how she goes for a week.  If you're back to square 1 take the new MAF off and refit the old one.  Tell the parts dept you only had in on for a couple of hours 

Then replace the O2 - no going back with this one though...... and clean the TB again.

If none of this works, probably best to bite the bullet and take it to a garage.  VW dealers are rip off merchants, see if you can find a good local garage or vag specialist.

It would be a lot easier if you had vag-com as you could log the readings from each sensor and look for any abnormal readings that could indicate a problem.  Fault codes alone quite often aren't enough to diagnose a problem.

[Chris 'N' Jen]

Thats a great help mate.

Thanx very much. If wether permits im going to clean the throttle body this weekend. Its got some fuel system cleaner in at the min. think i need to go down to the local boyo place and thrash a few of em (or try anyway) Typically the throttle body is at the back of my engine 

Thanks again