Hi all,  can anyone please tell me what it will the good value for the vaccum for a skoda fabia 1.2 htp or where i can find some tehnical specifications. The value is 18.09 and i think is not good. Thanks all.

12 hours ago, Liviu1984 said:

the good value for the vaccum

What do you mean by "vacuum" in this context, where are you measuring, and what units are you quoting that value in?

I guess you mean intake manifold pressure at engine idle?

I can't find a log-file for our 1.2 htp just now, but can easily produce one in the next few days. 

My 9N Polo (with 4-cylinder engine, so not really a good comparison) sits just above 300millibar at idle revs, fully warmed up (about 680rpm).

Which is about 18" Hg absolute yes?

1 hour ago, KenONeill said:

Which is about 18" Hg absolute yes?

Is it? I wouldn't think so.

Typical minimum vacuum values are between 22 and 27 inHg so 18 inHg is entirely plausible.

I get 18/29.9 = 0.6 atm/ or 600mbar-ish?? So not a good manifold vacuum.

 

Should I be doing 1- (18/29.9) and getting 0.4atm instead? That makes more sense in context.  Still not close to my logged 0.3atm/300mbar as Ken suggested?

 

I do seem to remember the 3-pot mani vac isn't as good though, will try to check later on ours, but busy this evening.

14 minutes ago, Wino said:

Should I be doing 1- (18/29.9) and getting 0.4atm instead? That makes more sense in context.  Still not close to my logged 0.3atm/300mbar as Ken suggested?

 

I do seem to remember the 3-pot mani vac isn't as good though, will try to check later on ours, but busy this evening.

 

You were right first time, 0.6 bar, which suggests the OP has a leak to fix somewhere.

Brake servo hose?

 

23 minutes ago, Wino said:

Brake servo hose?

 

 

It's always the prime suspect isn't it

Yep. I reckon if you flagged down all the VW group cars made between 2000-2010 half of them would have cracked/split vac servo hoses.  Dates picked out of a hat, and stats made up, obviously, as one does.

Thank you for information Wino. Where can i find a some pictures about that hose?

33 minutes ago, Liviu1984 said:

Thank you for information Wino. Where can i find a some pictures about that hose?

 

Look for cracks in the plastic pipe at the connections like this....

 

 

 

 

 

Edited 12 September, 20196 yr by TMB