black smoke!

[greenfyregirl]

Hello
I have got my car to start and run, but there is thick black smoke coming from the exhaust.
I have screwed the volume screws in to a quarter turn from
tight and it makes no difference. the idle screw has an impact on the car running, but not the smoke.
is there anything i can try, or see if it actually moves and take it to a garage?!!
thank you in advance!!!

[greenfyregirl]

it's 32 solex carbs by the way.....

[broady_6]

are the floats working? if they arent then the needle will be open all the time, so it will just flood the engine will fuel. When was it last serviced? got a good spark, timing set correctly? has it stood for a while? take it for a short run to warm it up and see if its clears

[Editor]

Are the choke flaps opening? Take a look with the air-cleaner removed. That will also let you see if fuel is pouring into the carbs, showing the float needle valves are not closing.
It may just be a matter of giving it a blast, but if it's not run for a while, it might be the float valves, as Broady suggest.

[greenfyregirl]

Hello and thanks for replies

I have cleaned but not replaced the float valves, as the empi ones didn't look amazing. I think i checked them ok,blew into the pipe etc, is there a good test for them?
The chokes I hope i have disabled, the butterflies are open all the time.... is there a way to check that i've done that properly?

[broady_6]

why have you disabled the chokes? And how have you? To check theyre staying open, take the air filter off and run the engine while having a look and reving it to see if they move.

If you can post some photos of your engine bay im sure it will aid us

[greenfyregirl]

because they don't work. So following the john muir book,i wrapped up the electric cables and dropped the stepped cam.
they are staying open now! ok il post a pic

[Editor]

Have a look at the mixture screws - take them right out and make sure the needle ends are pointed, not broken off.

The only other thing I can think for a rich mixture is that the accelerator pump is somehow working all the time. Not sure what happens if their diaphragms have holes, but I wouldn't have thought they would squirt at all.

Do you get even more black smoke when you blip the throttle?

[greenfyregirl]

yes loads more, it's sooty in blasts then!!
i have turned the screws to no avail, even right in to a quarter. i'm hopefully borrowing a fuel pressure gauge. i changed the float valves for the empi ones. perhaps it's the new fuel pump...
il check the accelerator pump - i did change the diaphragms. praps theyre in wrong..

[Editor]

I think the Beetle fuel pump does produce a bit more pressure as their carb is higher up than a Type 3. I think 3.5 psi is Type 3 and around 5 psi for Beetles, but that's from memory, and we all know what happens to that as one gets older! Obviously you've not got a FI pump in there!
It does sound like something's not right in the carbs. Are these the second-hand ones you got recently?
Run the car without the air-cleaner assembly. Look down into the carb throats and see if any fuel seems to be dribbling in. The idle mixture enters below the butterfly, so at idle there should be no fuel flow visible. If there is, you have a problem with the float(s), the float valves, or maybe main jets. Check the main jets are screwed in (access plug will need removing to get a screwdriver in); make sure all the other jets and air-bleeds are clear. Is there a number on them? X127.5 looks the size for '71. check the floats for leaks (shake to see if there's fuel that's got inside).
Check the floats are assembled correctly - there's a spacer above the float - may be a metal strip or plastic bridge. With the carb top upside down, you shouldn't be able to blow air through the inlets if the needle valves are sealing correctly. There should be a 1.0mm thick washer under the needle jets.
If all else fails to reveal the problem, maybe I can dig out a pair of carbs and you can try those.



Excessively worn throttle pivot bushes usually allow excess air in, rather than fuel dribbles, so i doubt it's that.

[greenfyregirl]

Hello- finally
I took the car for a test drive after replacing a new, but rubbish spark plug and the engine was really lumpy. So I gave in and took it to a garage- the mechanic said i had two cylinders leaking fuel.... so there we go!! today we dropped the engine- a bit traumatic to say the least!!
thanks for all the suggstions

[greenfyregirl]

the engine isnt quite out yet, as we cant get the car high enough !! lol!

[Editor]

Hmm - a mechanic in a garage who couldn't get the car high enough to remove the engine? Is the gearbox being supported - it mustn't be left hanging or you'll be looking for a front gearbox mount.

[greenfyregirl]

no thats us on the drive!! lol! yes we have supported it

[broady_6]

If you drop the engine on to a sheet for 8x4 ply. then jack up a rear corner you can slide the engine out on the board. thats the trick i use. works every time

[greenfyregirl]

Thanks its out now and very sooty!!

The oil smells of petrol.. is that a valve/piston/cylinder leaking thing? ( ive changed the fuel pump)

[broady_6]

damn, ive was going to say fuel pump!

It could be, its a shame you took the engine out. a compression test would have told you a lot. but take the head off from the side which your mech said wasn't running. it sounding rather like a top end rebuild. and as you've come this far it measure the bores and fit new piston rings.