Sad Question

[2052006 10]

OK, so I understand how the SAD operates and I believe mine is working correctly (have taken it off and tested it and it appears to be ok).

 

However, when first started from cold, it struggles to keep going (about 7/800rpm) then after 20 odd secs, without prodding the throttle, it will raise to about 1100 rpm for a few minutes whilst engine warms and then go back down to a steady idle at about 7/800 when warm and is fine.

 

My question is why doesn't it immediately go to 1100 rpm when cold, because as far as I can deduce, the SAD will already be open (even before starting - as it is only closed by a warm engine).

 

Is something else wrong such as fueling for the extra air from the SAD OR are do they all do this - but why? The problem is that it can stall when first moving off before idle has raised....

 

P.S. Have cleaned out throttle body, all breather pipes etc. Only thing I haven't yet touched is the AFM screw.

 

Any thoughts?

[welshpug 1,657]

sounds normal to me!

 

mine will hunt for a while if I dont prod the accelerator in the first few seconds, it does then settle to a good idle though.

 

its not only a warm engine that closes the SAD, it has a bimetallic strip heated by electrical current, so if you stop the engine, it will start to open, even though the engine will still be hot.

[mickie 3]

on a cold start i have to keep my throttle open for a few seconds or it'll stall but then idles fine.. randomly after coming down from about 100mph it idles high but if i blip the throttle it comes down to 800rpm..

 

dunno if thats normal

[richsmells 2]

on a cold start i have to keep my throttle open for a few seconds or it'll stall but then idles fine.. randomly after coming down from about 100mph it idles high but if i blip the throttle it comes down to 800rpm..

 

dunno if thats normal

 

Exactly what mine does. Wierd.

[2052006 10]

Sounds normal then, I guess it's just a quirk of these engines, but I wonder if they were like this from new?!

[lagonda 42]

Firstly I'd try raising your hot idle speed, as 700-800 is really too low. You should have it set at 950-1000. You might then find it will start & run OK.

My SAD did need adjustment... it would start & then stall, but my hot idle was OK.

Now it starts at around 900 but doesn't stall. The idle slowly increases to around 1400, then goes back to 1000 after 8-10 minutes.

So ... you can adjust the SAD, but you need to make sure your HOT idle is correct first.

[Andrwn8304 0]

Firstly I'd try raising your hot idle speed, as 700-800 is really too low. You should have it set at 950-1000. You might then find it will start & run OK.

My SAD did need adjustment... it would start & then stall, but my hot idle was OK.

Now it starts at around 900 but doesn't stall. The idle slowly increases to around 1400, then goes back to 1000 after 8-10 minutes.

So ... you can adjust the SAD, but you need to make sure your HOT idle is correct first.

 

I have to sit rev mine till the oil pressure builds up then its hitty missy if will idle but does idle 95% of the time till I drive off and get to a junction then it stalls.

 

How do you adjust the S.A.D.

[lagonda 42]

You'll need to take it off first, which means removing the AFM & its pipework. The SAD is held on by two small (10mm?) bolts underneath, the rear one's a bit hard to get at.

Once off, clean it up & you'll see a small nut, 6mm I think. Note/mark its position, remove this & one or two washers, clean the area, & also spray in the hole & the pipe ends with carb cleaner/WD 40.

Now replace the nut & washers & tighten lightly in the original position. Now get some leads with lucar type male ends, plug those into the SAD & the other to a battery/12v source. Looking through the SADS you should see a pie section clear through to the other side. The 12volts heats an element which slowly closes that gap.

On my original setting, it closed in 4 minutes, which was too soon. Adjusted it now closes fully in about 11 minutes, but is almost closed in 8 ... it takes a while for the last chink of light to disappear.

To adjust it, the nut goes on a stud which alters the position of the vane, & therefore the time it takes to close. The stud runs in a small slot, which is the limit of adjustment, so you just move the stud away from the original position to change things, & tighten the nut. If the vane is stiff, you can manipulate it a little with a small screwdriver. I moved mine from one end of the slot to the other & am happy with the result, but if I had a bit more time spare I'd probably tweak it back slightly & see how it ran then.

It does show that these things age, so if you can't adjust it to close in less than at least 8 minutes, it might be better to buy another.

Hope that helps; incidentally I noticed that the maximum idle it reaches soon after starting is actually 1700, not 1400. As stated before, it's essential to make sure your HOT idle is around 1000rpm first. One of the forum Articles describes the SAD & its operation, I recommend you read that first as it'll help you understand how it works & will clarify some of my advice if it's not clear. Good luck with it!

[Andrwn8304 0]

Took mine off when I changed the Gearbox back and look at it sprayed some carb cleaner in it and moved the white disc inside to make sure it was free which it was, but i didnt do a resistance check on it which might be worth having a go at.

 

So with that in mind it might be worth a new one been offered a second hand one for £20 inc P&P which they said they guarantee it to work if not a refund or replacement.

Edited April 5, 2007 by Andrwn8304

[mossy 0]

Just to let you know the SAD should only get around 9 volts and is controled from the ECU via tha Tachy relay!

 

Source - Auto data