20Vt trouble

[20vcqdriver]

Well after standing for 5 months, started the old beast up after the usual plugs out and wind over to get oil round to get pressure, then started her up and left to idle for a minute and then went to reverse the car out and as soon as I opened the throttle she stuttered and almost died, some blipping the throttle brought the revs up and so long as I did not shut the throttle engine kept running and managed to reverse out onto the drive. Once warm the problem virtually disappeared but on starting from cold the issue returns. Not been out on the road as no tax yet, but wondering if anyone on here can mention some ideas and see if you come up with the same conclusion. New hoses and clamps fitted from turbo to engine during charge cooler install and majority of Vacuum lines replaced with silicon equivalents too, so do not think I have an induction leak. Was hoping for a trouble free start to this years quattro driving...

[Puglife]

What is there in the form of idle sensors or stabilisation valves? Possibility it could be that, or another possible problem area would be the Idle switch on throttlebody.

[20vcqdriver]

Car idles fine, it is when you come off the throttle switch that things get unstable. Will tick over smoothly all day... present suspect is the MAF but this was changed last year (admittedly for a 2nd hand one) and do not wish to spend a fortune on a new one if there is something else at fault I have not thought of.

[mikes2]

fault codes should be the first port of call.

I'd be inclined to suspect a good run may see this sorting itself.

[4v6]

Originally Posted by mikes2

fault codes should be the first port of call.

I'd be inclined to suspect a good run may see this sorting itself.

I suspect a series of test pilots may be willing to perform such a service....

Hope you get it sorted asap.

[martinjs]

Could be the maf, try it with it disconnected.

[dynamodav]

How about drive it around for a little while and see if it fixes itself, you did just start it up after 5 months.

[20vcqdriver]

Further developments... Took a chance and drove it 1/2 mile down the road once it had warmed up. CAr is only boosting to mechanical boost of 0.4bar. Not sure if a faulty MAF would cause this or if I have some other unknown issue. Was also making an unusual whooshing noise as I opened the throttle. Doh! No sign of an air leak but they can be a b***er to find...

[quattroamm]

Hi, can you give some details as to which chargecooler you have used and where it is fitted, thanks.

[20vcqdriver]

Originally Posted by quattroamm

Hi, can you give some details as to which chargecooler you have used and where it is fitted, thanks.

No Probs. See pics. Had to modify it mind you as I wasn't happy with the cooling arrangements with only the centre getting most of the water so as ever I modified it.
It appears I have a mammoth boost leak on the inlet manifold Though trying to find it is turning into a mare of a job. Going to try and borrow a boost leak tester from Tim C.