General new vacuum advance unit > sluggish driving

[bumcheeks]

for some time now I've had no hose from the vacuum unit to the carb, although its been running fine without it, i decided its about time i sorted it

I just fitted the new unit and hose this morning and took the panda out for a spin and its never felt so sluggish, it felt like i was loosing revs now and again.
would the carb need to be retuned or have i buggered up the distributor whilst fitting the new vacuum unit?

 

[Martiny10]

The timing is different with the vacumn advance fitted, so the distributor will require moving (rotational adjusting).

Haynes manual is pretty good for the correct timing and the procedure.

Regards,

Martin

Fix It Again Tony!
Would swap for X19, Montecarlo Spider or GT.i.e in average/poor condition! Scottish based would be nice.

 

[John H]

Originally posted by Martiny10
The timing is different with the vacumn advance fitted, so the distributor will require moving (rotational adjusting).

Haynes manual is pretty good for the correct timing and the procedure.

Agreed.

IMHO best set with advance pipe disconnected and plugged to 2 degrees BTDC.
With the advance unit reconnected the timing at tick-over goes up to 15 degrees or so, depending on the particular unit - the specification for the vacuum advance is something like 13 degrees plus or minus one.

There are timing marks at both ends of the engines I've looked at - I have a preference for the gearbox end, as the marks on the flywheel and gearbox casing inspection hole aren't likely to be in the wrong place.

If the carb mixture was adjusted with that pipe disconnected (or the diaphragm popped in the advance unit) the mixture would need to be reset: as there is a substantial inlet leak that way.

 

[bumcheeks]

ah that makes sense, cheers.
is the rotational adjusting done by using an allen key in the distributor body to adjust the dwell angle?

 

[John H]

Originally posted by bumcheeks
is the rotational adjusting done by using an allen key in the distributor body to adjust the dwell angle?

No. Although they do interact.

Set the dwell angle first. (allen key, as described above).
If you have a meter you do it with the engine running:
51 to 55 degrees for Magnetti Marelli.

Gap of 0.45mm if you have to set with a feeler gauge.

The above is for the "FIRE" engine - according to "Haynes".


Then timing:
Two 10mm AF bolts secure the distributor body to the cylinder head -
Just slacken them a half turn, or so, and the whole distributor body can be turned to adjust the timing.
Retighten again - don't get too carried away, as they are tapped into the alloy head.

 

[bumcheeks]

thanks for that, I'll have a bash when i get home... if i get home! and the car doesnt keep stalling on the way back!