boost leak?

[Biggss2]

Hi all,

I have just cleaned my MAF in IPA in the hope it would give me better mpg/power...

N75 valve is disconnected, and there is some sort of chip switch i have bypassed i understand its some sort of superchips chip?

the problem im having is there is a stutter/hesitation 3rd gear, when belting it/joining the motorway.

If im giving it beans on local roads, its not noticeable, Initally i thought its the maf hose not on properly, Ive secured this to the point where if i tighten it anymore the jubilee clip will snap!

Im thinking, leaking diverter/dump valve maybe? (standard item at the moment)

or is this a symptom of the car knocking/pinging? i run it using BP optimum unleaded fuel.

Im sure this car has soo much more to give.. powerwise.

or could it be a lambda sensor issue, I have yet to VAGCOM it, got lead and VCDS just working all hours at work

any thoughts/ideas/suggestions would be much obliged.

Many Thanks in advance..

[newsh]

You need to pressure test, there is no other way.

[Biggss2]

sorry for sounding dumb, how would i do this?!

[UrS4boy]

Sounds more like a weak coil or bad plug starting to act up. You don't say ABY or 3B. If ABY you could use this post to help you with finding the weak coil:

http://forums.quattroworld.com/s4s6/msgs/22611.phtml

[Biggss2]

Hi URS4

its an aby!

it does struggle to start from a good bl;ast/warm too!

Plugs maybe?

[Biggss2]

Ive not long changed the coils

[UrS4boy]

Hi URS4boy. its an aby! it does struggle to start from a good blast/warm too! Plugs maybe?

Hmm... that makes me think fuel pump or fuel pressure regulator but it could be anything.

Click on ME and then the labels for the fuel pump and FPR for more info.

Could also be a G62 issue (making the engine think it is still cold even when it is warm)
(another label for you to click on).

[Biggss2]

hmmm, I changed the FPR off one on an audi a4, as i thought this was the problem, when it wouldnt start, as fas as i can remember it was the same bar pressure it provided/ same part number?!

fuel pump is new too!

g62.. is that the thermostat? eng reaches, holds temp ok though?!

[Biggss2]

and what a useful link.

thank you!

[UrS4boy]

g62.. is that the thermostat? eng reaches, holds temp ok though?!

No, the G62 is not the thermostat. Click on "G62" in that link.

[newsh]

http://www.s2forum.com/forum/search.php?searchid=1959327

[Biggss2]

Hmmm

Going to go with the easiest option 1st change the plugs..

Newsh the link doesn't bring up anything?

Got a dreaded oil leak aswell that seems to be coming from right hand side of block that needs seeing to! Will i ever get this car running right! The oil light bleeps aswell (level is fine), could this leak be from the oil switch?

[Biggss2]

Thanks for your help guys..

I think I'm going to change the fuel filter too see how much of a difference that makes!

[newsh]

I ran a search on "pressure testing how to" it came up with a list of topics, you have some reading to do Basically, you pull off the hose at the maf and plug it with a cap with a tyre valve in it and blow in air from a compressor, this will show up any big leaks in the inlet tract and PCV system. To really test the IC and inlet hoses properly up to a bar or so you need to isolate the PCV by disconnecting and plugging the connection on the side of the maf hose (20mm plug) and the hose going to the boost tube.
The classice leak, apart from splits and loose clips, is the IC O ring being perished. This is the O ring which seals the joint between IC and cross member at the LH end of the IC. You can easily fit a new O ring (bumper removed) but a lot of people do the "Mark H mod" which is to fit a modified silicon reducer hose over the join, a search will find you the details.
It takes a while to get these old cars sorted but when you do at least the parts you fix stay fixed
Are you really sure you want a 3B in your life as well??

http://www.s2forum.com/forum/search.php?searchid=1959546

[Biggss2]

cheers newsh, im hoping to change spark plugs, fuel filter, and the g62. thinking about it it does run a bit rich smells quite strong, on standstill. as for the 3B its to ball about in while i get the niggles sorted on this one!!