Engine not running right

Hello again Peddersgolf,

The point about the flap in the intake pipe is that you need warm air whilst the engine is cold to assist the combustion of the air/fuel mixture going into the engine.

However once the engine has warmed up to its proper temperature then the flap moves and colder air is directed into the carburettor/engine. The cold air is denser and contains more oxygen than the same volume of warm air. More oxygen=better burning in the cylinder=more power=more efficient. This is why many of the performance air filters (K&N) have a cold air induction feature.

As you have found out by experience sometimes the carburettor/intake design suffers from 'icing' when the engine is cold, or the outside temperature is too low. Although the flap is moved by using the vacuum from the engine, the vacuum is controlled by a tempreature sensitive valve in the air filter case.

I don't know enough about the citi but you may be able to use a 'stock' filter case with the valve inside it - or buy a valve and modify your existing case.

Have Fun  8)

Andy

Thanks for the info!

Do you have a pic of where the pipe rests on the manifold? I was told there is a shroud that can be bolted onto the manifold

Cheers

deefadog,

Sorry no pictures and my son has the 1.1 away at University at the minute.

There is a shroud that fits on the exhaust manifold and has a round 'outlet' that the flexible pipe goes onto. This is for 1.1/1.3 Small blocks - citi's are of couse based on the Big block which has a different manifold I think.

Andy

deefadog said

Thanks for the info!

Do you have a pic of where the pipe rests on the manifold? I was told there is a shroud that can be bolted onto the manifold

Cheers

On 1.1 & 1.3 ORIGINAL MK1'S THE EXHAUST MANIFOLD IS TO THE FRONT OF ENGINE  WHEREAS ON 1.3 CITI, 1.5,1.6 & 1.8 MK1 AND 2 GOLFS THE MANIFOLD IS THE SAME AND LOCATED AT THE REAR LEFT OF THE BLOCK, YOU WOULD SEE A SHROUD THAT YOU CONNECT A WARM AIR FEED PIPE TOO, NOT ON THE CITIS UNLESS THEY WERE FITTED TO THE EARLIER MODELS, BERT CORRECT ME IF I AM FELLA.
ON CITI GOLFS THIS IS NOT THE CASE, DUE TO IT BEING A 1.3 BUT A 1.6 BLOCK, I HAVE LOOKED ON MINE AND WHERE THERE SHOULD BE HOLES FOR A SHROUD, THERE ARE NONE, SO THIS IS WHY I HAVE JUST ROUTED A PIPE TO THE BACK TO DRAW WARM AIR.
ON CITI'S THE CARB IS DIFFERENT AND WAS DESIGNED FOR WARMER CLIMATES THUS NO NEED FOR A WARM AIR FEED.
THIS WAS A MOD BERT PASSED ONTO ME AND FROM EXPERIENCE TO TODAY IT HAS WORKED A TREAT.
I THINK DURING THE WARMER MONTHS I WILL REFIT THE ORIGINAL COLD FEED ONLY AS THIS WAS THE CASE WHEN I 1ST BOUGHT HER LAST SUMMER AND RUN SMOOTH UNTIL THE WINTER MONTHS AND IT RUN TERRIBLE.
GOT THE BEST OF BOTH WORLDS THEN :wink:
SORRY ABOUT UPPER CASING, JUST REALISE AND CANT BOTHERED TO TYPE IT ALL AGAIN LOL
PETE :wink:

Ah i see thanks, so just point the tube at the back of the manifold then yes? How did you fix it so the pipes stays in one place?

Thanks

o yeah one more question, how much should the uk intake cost from a scappys or second hand? as i can get one delivered for around ?15 seems like a goo price to me

If you look at the pic, i cut a long enough piece of piping and cable tied it.
For the mod part of air filter box, i paid ?5 from my local scrappies, ?15 seem a little too steep bud.
Pete

Thanks for the info!

Right then Finally got the uk inlet - woopeee

I have not fitted it yet, and have a question -  when looking in at the cold air opening all i can see is a metal pin coming down vertically, ican't see a falp of any kind - is this ok? also what do i do with the cold air opening - should i block it up so it just takes the hot air?

Thanks

deefadog,

have a look at this other thread, in it there is a link to some pictures :-

http://www.vwgolfmk1.o…wtopic&t=21060&highlight=

The metal pin you can see is part of the thermostat - and I guess it will be holding the flap/s shut (see the pictures in the link above and you'll see what I mean). What was the air temperature like when you were looking at the inlet ? - if it was 20 deg C or above then the thermostat will have correctly closed the warm air flap. If it was less than 20 deg C then the flap should have been partly or fully open - stick it in the freezer and see what happens  

Leave the cold air opening open (at least until you have it fitted and have tested it for a bit.

Keep posting

Andy

That picture looks different to what i have? I definatelly have the same one which is in the picture on this thread!

If looking in there is a hard pastic piece about 20mm coming from the inside top with a ridge in it, this is where the pin is attached too, i try moving the pin and pushed to hard and it fell out should be able to get it back in with patience

I thought it was the vacume that moved the flap and not a thermostate, maybe there are 2 types?

deefadog,

It's both the vacuum and the thermostat that affects the flap/s, the vacuum is contrlled by a temperature sensitive valve in the airbox as decsribed in the other thread.

Any chance of a picture of your's showing the inside ?

Andy

I'll have to take a pic tonight as i am in work, i'll post it tomorrow!

Thanks

OK deefadog - then we'll see if we can help further.

Andy

Here we are

When i looked at this last night i noticed that the plastic piece that the pin attaced too does push up, so i guess tghe vacume will suck this up when cold and allow the warm air through from the manifold?

I don't see a thermostat though????

deefadog,

What car did the air inlet part (that you photographed) come from ?

It doesn't look the same as the inside of the one in the other thread…

Andy

Not sure to be honest, only that it was a mk2 1.8 carb i think

deefadog said

Not sure to be honest, only that it was a mk2 1.8 carb i think

OK - looks like they changed the setup for the MK2 (I don't know much about them).

From what I can see in the picture, there is no thermostat bit and it just works off the vacuum - but you'll need the temperature regulator inside the airbox (as shown in the other thread) - BUT - I guess you won't have that as your car didn't have a warm air feed originally    

If you connect it directly to the vacuum pipe then the flap will always be open so you'll always draw warm air (assuming your pipe is near the exhaiust manifold.

Need to take stock and work out what's best from here on…

Andy

Ther is no vaccume feed for it So i gues i would have to push the plunger up and insert a self taping screw itno it to keep iyt open.

Other than that, i see no reason not to block up the warm aitfeed and take a tube from the cold feed to the manifold? Same thing is'nt it? An i'll just swap the inlet around, standard for the summer, this one for the winter months!

Sound about right?

deefadog,

I think that's what someone else earlier in the thread does - and it's a good place to start and see how you get on - the 1.5 GL we had was made like that !

Some of these 'cold start' bits were there to reduce emissions during startup conditions rather than for best running. But they do have their place in providing a reasonably stable inlet air temperature during varying conditions.

Perhaps the best answer is something crude and simple llike you suggest - OR - go the whole hog and get the complete airbox assembly with the temperature regulator etc.

LLet us know how you get on.

Andy

Thanks, should fit it the weekend, all i need is sun 5 degree weather to test it