Anybody happen to know what is the intern diameter of the vacuum line between the throttle body and MAP sensor on a 1.2 8V?

Within sane limits, it's going to make no difference.

The O/D is more important (for the rubber bits on the ends).

There are no extra rubber bits at the end. The vacuum line just goes over the nipple on both the MAP sensor and on the throttle body and there is no clamp to fix it on. I seen vacuum line like you describe but this one is not like this. This line looks more like a fuel line and is mounted like one too.

dumbledore said:

There are no extra rubber bits at the end. The vacuum line just goes over the nipple on both the MAP sensor and on the throttle body and there is no clamp to fix it on. I seen vacuum line like you describe but this one is not like this. This line looks more like a fuel line and is mounted like one too.

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Then the chances are, it ain't vacuum hose! Replace with extreme prejudice: vacuum hose should be, to all intents and purposes, rigid.

fingers99 said:

Then the chances are, it ain't vacuum hose! Replace with extreme prejudice: vacuum hose should be, to all intents and purposes, rigid.

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Should be a vacuum hose as the MAP sensor measures manifold pressure. The problem on FIAT is that the MAP sensor is mounted on the firewall. It will require as a result to have some flexibility in the vacuum line. So I am pretty sure the line is OK not to be rigid. The lines looks like a low pressure fuel line. At Halfords they sale lines that look just like that one has around 3mm ID and the other one has about 5mm ID. Outside OD is same. The question I have which of these two to use?

I have 3mm ID silicone lines for vacuum hose on mine, never had any issues using it.

Of course it should be a vacuum line. I really cannot understand why you're intent on replacing it with a pressure line. :bang:

The real thing isn't exactly expensive, and my guess is that the local scrappy would let you have one for a quid.

If you must continue with this perversity, the one with the smaller i/d is obviously likely to be more resistant to crush.

well i'm not saying its right, just that i never had any issues is all. It certainly would be possible to crush on of them if your not careful, tiny ID is better for sampling pressure/vacuums than larger ID etc - i can see the downsides.

Not getting at you Blue -- posts crossed. But you can buy small diameter vacuum hose, in silicon too.

Reality is, that the resistance to crush need'nt be that great if the rubber end bits can stand it.

As it happened, I did go for the smaller id one that I bought from Halfords. The one that was there that failed looked the same as the one I replaced. So it must have been to wrong type to start with. The only issue I had with the smaller id line was to try to push it over the MAP sensor as that one has a plastic nipple and to much force can brake the nipple. The nipple on the manifold is metal and there is no issues. The other issue I fear is that the small id pipe may become blocked with debris which could led the wrong vacuum readings.

Should be OK.

Although I tell folk to blow them clear with an airline (after disconnecting both ends!) I've yet to see one with owt in it.