vaccum lines

[H48HPE]

ive just been reading the thread about rich's starting problem over on the montego forum, there is mention on there about the vaccum switch on the carb.

this is the problem on my car: if i disconnect the vaccum pipe off the inlet manifold i can suck air through it quite easily, so i tested the air cleaner vaccum switch an thermostat and that allows only a small ammount of air to come through, possibly from its connection on the air filter box. then i tried sucking ar through the pipes that go to the carb an the distributor (which are joined) and i could suck air through those very easily.

is the above normal is my first question? and my second is, what purpose does the vaccum attachment on the carb serve (1990 1.3 engine manual choke)?

andy

[E_T_V]

ok as far as I know this is how it goes.

There is a vacuum diaphram on the distributer which has the effect of advancing or retarding (I forget which) the timing when the engine is underload cold etc. if you leave the pipe to this connected and suck on the other end you shouldn't be able to suck much through, you may also hear a faint click from the distributer. (Don't suck too hard or you might damage it). If you can suck easily then this is the bit at fault. There are several different arrancements of pipe to the distributer dependins on age and model but they all have the same effect in the end of messing with the timing.

There are various other vacuum bits on the car which are less important but can still muck things up if they aren't right.

It is all easier to show you rather than describe so if you fancy a trip up to Stocksbridge we can compare notes.

[G Force]

Hello, there is no vacuum switch on the carburetor of 1.3 versions with manual choke fitted as standard.

The distributor vacuum unit is there to advance the ignition timing when on high cruise/light throttle/light load running conditions. It is an economy device and when it is faulty you will experience poor fuel consumption and poor performance.

Cheers Gary