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 May 11 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.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[bacardincoke 44 1 Cars]

Just a follow up to this... was niggling me that I couldn't get the initial cold idle below 1600 rpm (even it now only stayed there for a much shorter time).

 

Have changed out the coolant sensor (Bosch 0 280 130 026) and taken out / given the throttle screw a thorough clean (was quite gummed up in the groove near the conical tip).

 

Checked the resistance of the original sensor, it was a Bosch (same number) also and perhaps original to the car?

 

Showed it was still working but impossible to say if it was maybe progressively failing and on the way out.

 

Back down to 1450 rpm... don't think it was just the one thing causing the change in cold idle, but a combination of all the above.

 

The 'O' ring on the idle screw... don't need one at the moment, but has anyone a source for them, seem to be a bespoke shape / size?

 

 

[Leslie green 126]

Good stuff , I swapped out my sad valve today for the working one (112) and it started and went to 1700 instantly ,after a couple of mins it had dropped a bit to 1500 but a rev and it dropped to 1000 but crept back up to 1300 again...arrrhhhh !Nothing has improved , I tested the old 182 one and you guessed its working too , gave the ends a little clean while it was closed up.

My throttle body needs setup correctly again and I need to clean that idle screw which is fully closed at the minute too.If no improvement I've an air leak or that coolant sensor is not working right , the plug too it is broken so there is no metal retaining ring anyway so I've bought an injector plug new with the wiring in it for 4 quid which is great for testing the sad .

My next step is calibrate the throttle body correctly , the micro switch clicks as soon as you move the throttle but the end stop isn't set right as I thought it controlled the idle ,it doesn't the big brass screw in the top does .

The inlet manifold gasket , throttle body o ring , or the bellows to the afm could be leaking , I know even the sunroof vac switch is leaking as you hear it hiss as soon as engine turned of so I may block that off too .

Edited yesterday at 05:34 PM by Leslie green

[bacardincoke 44 1 Cars]

Reading between the lines it looks like both your SADs are functioning as they should, though if the weather with you is anything like it is here the high ambient temperature may be influencing things a little.

 

On a test day that's closer to 20 degrees they'll may well perform slightly differently.

 

Wouldn't be surprised your issue is because of one (or a combination) of the things your going to check, pain having to go through it all but I think your heading in the right direction.

 

Start with the small / easy fixes and work up to the bigger ones, you never know your luck and nail it early on.

 

An odd one to consider is the dip stick tube, see if the revs drop when the engines warm when it's out / then cover the opening with your thumb!