Hot/warm start issue

[Groundhog]

As per Mike2's reply it's likely the fuel accumulater or fuel pump return valve, both easily checked with a fuel pressure gauge if you have or can borrow one.

[fb1]

Cheers i'll try the relays. And ive got a mate that should have a fuel pressure tester.
Hope you all have a good christmas. I'll update after the fesivities.

[fb1]

Finally found time to pop into a friendly local vag independent garage just around the corner. He diagnosed coolant temperature sensor. Also not running quite right. Part ordered and should be fixed and engine set up correctly on wednesday :-)
Also qouted £350 to change cambelt, tensioner, waterpump and do oil and coolant service. Including parts. Seemed reasonable to me. Does that sound about right?

[fb1]

Still not running right. Ive now found that if i spray carb cleaner under the inlet manifold the revs pick up and seems to run lovely for a few seconds. I guess this indicates an air leak. Are there any vacuum pipes hidden under there or will it be the actual manifold? Also does anyone know of good independant audi garage in norfolk that has been around long enough to have actually worked on these cars? The guy i took it to, although a lovely chap, hadnt really worked on these before.

[msh]

Originally Posted by mikes2

Strong possibility of a fuel pressure problem - leaking injectors or the fuel pump check valve.

you could try unplugging the cold start valve to see if it improves. blue plug injector on the inlet manifold

VERY VERY HIGHLY unlikely - how do injectors suddenly start to leak and where do they leak on a running engine? Simptoms are exactly opposite.

[msh]

Originally Posted by fb1

Still not running right. Ive now found that if i spray carb cleaner under the inlet manifold the revs pick up and seems to run lovely for a few seconds. I guess this indicates an air leak. Are there any vacuum pipes hidden under there or will it be the actual manifold? Also does anyone know of good independant audi garage in norfolk that has been around long enough to have actually worked on these cars? The guy i took it to, although a lovely chap, hadnt really worked on these before.

If you're able to handle some basic tools, read my thread http://www.classic-audi.co.uk/forum/...ad.php?t=29491

Your problem sounds like mixture too lean, and if there's some leak as you've likely found, that's the reason. Now only question is why the ECU doesn't compensate for it - quite likely oxygen sensor is dead, and probably someone has adjusted the mixture screw to compensate for this for it to pass emissions test. There's a quirk with 2.3 engines - with more or less normally running ones, no like yours, which dies by itself - when oil cap is opened with engine running, engine is likely to stall, because that allows engine to draw in intake atmospheric air, not metered by metering head, making mixture lean - right, but warm engine with properly working oxygen sensor and rest of injection system withstands this - it for a moment drops revs, until ECU compensates for lean mixture, then it runs fine, while camshaft is pouring oil drops through open cap, lol.

Anyway, as for your problem - if you're able to handle some bigger tools, order new gasket which goes between both sides of intake manifold, and get yourself a cheap set of hexagon, torx and, I forgot what's the name for third type of usual bits, and ratchet, and take off the upper intake manifold - doing that will require usual treatment of long time not moved bolts - each bit hammered in before trying to undo that bolt - and it's quite likely that 6 mm hexagon bit will turn around head of some bolt due to need for excessive force, as these bolts tend to become stuck - so then suitably larger torx or other bit has to be forced in with a hammer to undo it - under the manifold look for perished idle speed valve hose, one or another, check if injectors are tightly in their places and inspect if both sides of intake manifold had a good seal and surfaces arent warped - although 2.3 short intake manifold is less likely to do that.

[Sandro]

Originally Posted by msh

If you're able to handle some basic tools, read my thread http://www.classic-audi.co.uk/forum/...ad.php?t=29491

Your problem sounds like mixture too lean, and if there's some leak as you've likely found, that's the reason. Now only question is why the ECU doesn't compensate for it - quite likely oxygen sensor is dead, and probably someone has adjusted the mixture screw to compensate for this for it to pass emissions test. There's a quirk with 2.3 engines - with more or less normally running ones, no like yours, which dies by itself - when oil cap is opened with engine running, engine is likely to stall, because that allows engine to draw in intake atmospheric air, not metered by metering head, making mixture lean - right, but warm engine with properly working oxygen sensor and rest of injection system withstands this - it for a moment drops revs, until ECU compensates for lean mixture, then it runs fine, while camshaft is pouring oil drops through open cap, lol.

Anyway, as for your problem - if you're able to handle some bigger tools, order new gasket which goes between both sides of intake manifold, and get yourself a cheap set of hexagon, torx and, I forgot what's the name for third type of usual bits, and ratchet, and take off the upper intake manifold - doing that will require usual treatment of long time not moved bolts - each bit hammered in before trying to undo that bolt - and it's quite likely that 6 mm hexagon bit will turn around head of some bolt due to need for excessive force, as these bolts tend to become stuck - so then suitably larger torx or other bit has to be forced in with a hammer to undo it - under the manifold look for perished idle speed valve hose, one or another, check if injectors are tightly in their places and inspect if both sides of intake manifold had a good seal and surfaces arent warped - although 2.3 short intake manifold is less likely to do that.

sometimes You write pure nightmare

[Sandro]

Originally Posted by fb1

Still not running right. Ive now found that if i spray carb cleaner under the inlet manifold the revs pick up and seems to run lovely for a few seconds. I guess this indicates an air leak. Are there any vacuum pipes hidden under there or will it be the actual manifold? Also does anyone know of good independant audi garage in norfolk that has been around long enough to have actually worked on these cars? The guy i took it to, although a lovely chap, hadnt really worked on these before.

You discovered problem Yourself... engine sucks by vacuum carb cleaner through "air leak" and indicates the problem. Find the crack or broken pipe.
If not, come to Chelmsford after 2 weeks and wil help to find You the problem

[msh]

Originally Posted by Sandro

sometimes You write pure nightmare

Sure - but in how many foreign languages you're able to write some nightmares?

[fb1]

Hi. Thanks guys most helpful. Although msh, my 'handling of basic tools' only goes as far as a hammer, 2 screwdrivers and a monkey wrench. My lack of oscilloscope and test tubes might hinder me slightly :-)
Ive yet to have more than 10 minutes to look over it properly. When i take off the inlet manifold do i have to remove much of the injection system?