11 Turbo running issue.

[jack joy]

Helps if I put in the right section!

Hello,yet another question! Sorry!
The 11 suddenly developed this running / idling issue I'm starting to run out of ideas.
It was idling perfectly and then stalled.Since then it will not idle below 1200rpm and hunts baldly,I held it at a steady 3000 yesterday and the misfire was still there.
It's had :
New manifold gasket,
New fuel pump +filter
New plugs
New Dizzy cap
Leads are good
Fresh fuel
Compression test (all cylinders at 11 bar!)
Finally a carb rebuild which made absolutely no difference! I've rechecked & blown through the idle jet which also has a new o ring.
Also popped a new coil on as I had one.
I haven't checked the Co at idle or fuel pressure at carb, but wondered whether the Fuel pressure reg could be the culprit? £50 for a ropy looking used one seems a lot to me..
Any thoughts would be bloody brilliant!
Thanks again ��

[Matt Cole]

Hi, try the idle jet again. These things take quite a bit to clean through. Is the mix screw still in the carb? If so take it out and see if the tip is still intact.

Take top of carb off and look down the ventury when it's running? Do you see fuel droplets? If so this will cause the engine to run rich and lumpy.

Do you have an afr gauge? If not, get one. This will tell you what the fueling is doing.

Have you looked at the plugs? Check if sooty. Another indication of poor fueling.

[jack joy]

Great !
Plugs only just gone in, but looking on the rich side. Idle jet out again for a clean. Mixture screw is virtually new and in place.
The car was fine and then it wasn't I know nearly a decade of sitting is going to reveal some probs.
Thanks again .
Really helpful ��

[Matt Cole]

The AFR meter is really a must these days to property set the carb up, especially after a rebuild.

[jack joy]

Re checked/cleaned idle jet ,which was clear.
Just looked down the carb venturi at about 1200 rpm and fuel is dribbling down fast.As I've boringly said already, this running issue came on all of a sudden just before I stripped, cleaned & resembled the carb.
Would a dodgy Fuel pressure regulator cause this? Having trouble thinking today!
I've just been given notice to clear the garage by the 24 July , so just need to get it mot'd quick!:|

Thanks again!

jack.

[Matt Cole]

Hi Jack. Ok at least now you now know what the issue is. Remove the first stage block.
1st stage is the jet that looks just like an air corrector jet (and they infact are interchangable) which is located in the triangular-shaped enrichment section that you un-screw (3 screws) from the passenger side of the carburettor.
Give it a good blast out with carb cleaner and compressed air. Refit and see if that improves it.

[Matt Cole]

Failing that, you can check the fuel pressure. Generally 4psi base and above boost pressure. If the regulator return is blocked or the reg is not working, then it is possible that the carb is seeing too much pressure.

[RussellT]

Are you sure your mixture screw looks like this?

https://goo.gl/images/Jvbc3H

Sounds like you suddenly developed an air leak. If you run the car and put your hand over the top of the carb if it doesn’t stall you have an air leak.

[jack joy]

Hi Jack. Ok at least now you now know what the issue is. Remove the first stage block.
1st stage is the jet that looks just like an air corrector jet (and they infact are interchangable) which is located in the triangular-shaped enrichment section that you un-screw (3 screws) from the passenger side of the carburettor.
Give it a good blast out with carb cleaner and compressed air. Refit and see if that improves it.

I checked and blasted the it through with a new carb cleaner . Saw a few bits of green corrosion come out ,but now looks completely clean everywhere. Put the carb back ,exactly the same problem �� ..Ordered a fuel pressure tester.
So grateful ,by the way .
Jack.

[jack joy]

Are you sure your mixture screw looks like this?

https://goo.gl/images/Jvbc3H

Sounds like you suddenly developed an air leak. If you run the car and put your hand over the top of the carb if it doesn’t stall you have an air leak.

It has a strong vacuum.stalls immediately. Also the new plugs are covered in carbon already.
Thanks again ��

[RussellT]

So suddenly running rich. Check the “float” floats and the needle valve operation.
I hopes its something simple
R