Running rough after fitting PCV valve

[daverclasper]

Hi folks

 

Vitesse Mk1 2 Litre

 

My car came with a tube fitted from the rocker cover, to the air filter box and the inlet manifold top hole blanked off.

 

My air filters were getting a bit contaminated with oily residue, so I blanked of the air filter hole and just left it open at the rocker cover.

 

I bought a second hand PCV valve, complete with hoses, that look like they may be original and a bit perished, but no obvious splits and fitted it. The diagram is probably old, but no holes (not sure what it's made of, doesn't seem like rubber).

 

Car now a bit more difficult to start and a rougher idle, also will stall when the revs are shut off (haven't driven it yet, so don't know what general performance like).

 

Also will stall when the oil filler cap removed, which it didn't do before.

 

Just wondering if the original valve was removed, due to engine issues or if I can get it to run ok with valve fitted, maybe mixture/timing alterations.

 

Any help would be great.

 

Cheers, Dave

 

  

[daverclasper]

Forgot to mention, Ran the PCV into the inlet manifold.

 

Dave

[Pete Lewis]

As the engine is now consuming any breatherfumes in via the manifold your original mixture settings will need some adjustment

may also be worth checking the needles are std spec

 

taking the cap off lets air in and the engine will speed up

 

 

pcv diaphragms can go very stiff and they wont work, it should stay shut until it detects any crankcase pressure , when it opens and eats the fumes , it does this continuosly , if its stiff cut a flat peice of poly or nick the marigolds and use to test a new flexible home made .

 

pete

[daverclasper]

Thanks Pete

 

I don't understand how the valve works.  The diaphragm looks like it would need vacuum to suck it down (but wouldn't get any from manifold as the little valve thing in the bottom would be shut).

 

Also when the round plate with the pin on is pushed down against the spring to rest on the 4 lugs, the pin doesn't quite reach the valve thing at the bottom.

 

Also if the engine does stall when rocker cap off and it shouldn't, is this related to the valve not operating properly, or something more sinister do you know please.

 

Haven't had time to try a homemade diaphragm yet. When you said poly, did you mean polythene bag?.

 

Any help would be great, thanks.

 

Dave 

[Pete Lewis]

with luck heres a scan of what the WSM says 

 

if the diaphragm is in trouble  use anything as a trial  

 

dont take the cap off its effect is not contributing any sense to what the carbs and breather do  its supposed to be sealed and fitted and mixtures set to behave as 'sealed'

 

there is no real test proceedure for the valve,    if its clean and all intact   go with the idea its OK 

 

 

 

Pete

pcv.pdf

[JohnD]

Is it the right way around?

The diagram in the PDF link from Pete will show you the correct orientation.

 

JOhn

[daverclasper]

Cheers Pete

 

That's cleared it up a lot.

 

Hopefully only one final question if you will bear with me. The WSM bit on reassembly it quotes " taking care to correctly locate the plunger in the center of the guides in orifice plate".

 

I assume this means the pin attached to the circular plate (or valve pin as the manual calls it)?.

 

Thanks, Dave 

[daverclasper]

Is it the right way around?

The diagram in the PDF link from Pete will show you the correct orientation.

 

JOhn

Hi john, thanks 

 

The diaphragm is correct way, though is not very supple and could be very old, so may the problem.

 

Cheers, Dave

[Pete Lewis]

Realy the diaphragm and its little plunger thingy just pop in the housing, on top of the spring and pop the lid on

Pete

[JohnD]

Diagram, not diaphragm.

The valve as a whole is usually mounted flat side up, with the lower connection, aka 'outlet', going to the manifold.

John