SAD issues

[Leslie green 126]

what I can see looking in to the one ending in part 112 looks like the pic on the left but that doesn't mean that's what it looks like when apart although it probably is  , I will definitely clean and test before trying to open it ,until I get the original out I dunno what it looks like looking in. I think looking at it you could just drill right through and use 4 tiny bolts to secure it too.

[bacardincoke 44 1 Cars]

Thanks for the PDF Leslie... answers quite a few of my questions about what they (and probably the others too) were requiring to be done inorder to refurb. one of these.

 

Nothing too arduous, but you'd still need to be reasonably handy at tinkering with things, could see it all going south for someone over stretched themselves.

 

Different if they were easy got / cheap, but there's a lot at stake.

 

Anyhow... today I also cleaned up all the other SADs I have / tested them together.

 

They were all already within spec. to a greater or lesser extents before, but each responded well to cleaning and it noticibly tightened up the readings further.

 

Small sample but maybe implies these things don't go wrong that easily and a clean is generally all that's needed?

 

I've 2x identical MK1 Golf ones and they now exactly match (to the decimal point) each another, also implies these things are pretty accurately specced.

 

The Golf SAD element is 35 Ohms, 182 was 49.

 

Both the Golfs take exactly 1:45 to close soley using 12v.

 

182 is back in the car, but it and 112 are each 49.

 

112 consistently takes 3:45 to close on 12V only.

 

14 Ohms of a difference might not seem like much, but in that comparison it more than halves the time to close.

 

At 3:45it's such a short time that my cars engine (from cold) is still cool enough to touch in and around the area 182 is sited.

 

I'm thinking the element works alone on completely cold starts and it's then engine heat that influences the SAD for warm starts and not a mix / overlap of the two.

 

Different engine / different requirements, but the MK1 Golf SAD is closed at 1:45 (and is sited relatively far away from direct heat on the intake manifold), the engine must barely be warm in that even shorert time, let alone there be enough engine heat to influence the SAD?

 

Was it Spoox you were referring to that are charging £360 for a refurb., saw them on their site, but not much detail given?

 

Found another reference in the Bosch material, this time to 183 (Citroen BX and mentioned by Spoox) as having 'Contour #3' - that coincides with your seller who lists it as his 3rd profile (maybe he's falling in line with the Bosch terminology for his own products?)

 

Bottom line is I'm increasingly reading stuff that makes me believe the different Ohms / flow rates and profiles do matter and probably more than you'd think despite appearing to be small increments.

 

 

 

 

 

 

 

 

 

 

 

 

 

[Leslie green 126]

No worries Martin , do they run at 12v though I'm wondering ?, I saw something said they are supplied by the starter at 9v (this may or not be true) and doesn't the element run all the time the car is running ,would seem a bit strange if it did but what would turn it off . 

It was spoox and I can see why the price was missing but some will pay it as there are none for sale anywhere else, What did you clean it with and I will give mine a clean when i get time 

Edited Sunday at 05:41 PM by Leslie green

[bacardincoke 44 1 Cars]

12v is just used across the SAD's own 2 x terminals to check that the aperture closes.

 

9v is the minimum you should be getting if checking the corresponding plug on the loom that connects to the SAD.

 

Now that you've asked, I can't answer that about whether or not the element heats continually, or switches off once engine heat has taken over (and how).

 

Like you say, at first glance it would seem unnecessary, even stress it for example, but then again maybe not... be very interesting to know.

 

Just small amounts of brake cleaner on a cotton bud, gently wiped across the faces of the disc., took quite a handful of them before they stopped coming out pitch black.

 

If yours are anything like mine you'll probably even see the tide mark left by the carbon (?) that's being pushed aside and left behind as the thing moves back and forth over time.

 

The scarcity / price of SADs must be getting to point it's likely becoming viable for someone to start providing replacement elements... you can now get them for the K-jet 'warm up regulators' (and not overly expensive either), might even be the 'Missingparts' guy who's doing them?

 

 

 

 

[bacardincoke 44 1 Cars]

At a bit of a loose end this morning... might, if I can build up the courage, go out to the garage later and swap about a few SADs, just as an experiment to see what comes up.

 

Should have listened to my own thinking out loud earlier, about the engine block temperature still being relatively cool to the touch at the time point the SAD was closing up entirely.

 

Makes sense then that it should be continuing to get voltage, otherwise it'd potentially start opening again if the engine temperature had not yet caught up with it.

 

Done a bit of homework and If I've understood correctly the SAD gets its power via the fuel pump relay, so the entire time that's running, so too is the SAD getting power.

 

 

 

 

 

 

[bacardincoke 44 1 Cars]

So... 112 in and 182 out, runs perfectly.

 

Not surprising really, the specs of each are very closely matched.

 

Makes for the same cold start of 1600 rpm, that drops steadily (after about 1 minute) down to 950.

 

Of note and potentially peculiar to my 182 is at 54 Ohms it's getting near the upper end of the Autodata acceptable range of 45 - 55, while 112 is exactly right at 49 Ohms, which is what Bosch say both should be.

 

That manifests itself in 182 taking 5:00 mins to drop to a warm idle, while 112 is 3:45 mins. which presumably is attributable to the greater resistance.

 

Both will consistently get these same figures over mulitple tests.

 

Reinforces again that apparently small differences in resistance can add minutes to the length of time the aperture stays open.

 

Have just done another cold start this evening (12+ hours since the last switch off) and all the above is repeated exactly.