Sad Issues

[Rob_the_Sparky 9]

I had another go at fixing this today, and my spare SAD isn't working either. The other one had actually started idling at 1000rpm by the time i got to uni, (an hour away) but it wouldn't make the revs rise when the car was started. Generally it would take a minute or two for the revs to rise up to 1500, then about 45 minutes for them to drop down to 1000.

 

I put the spare valve in, and the revs don't rise now either. I haven't started another 205gti from cold, but surely you don't need to use the accelerator to start them... This problem couldn't be attributed to dodgy wiring either could it?

 

Should i try to get another SAD that can definately works? This prob couldn't be caused by anything else, could it?

 

Does your car idle fine when cold but revs just rise and rise as it warms up? That is what I'd expect from a SAD issue...

 

Rob

 

P.S. They vary but some do need a touch of throttle for about 10seconds after starting to keep them going. After this period they should idle fine.

[ALEX 98 1 Cars]

I will get them both to the auto elec tomorrow... I would do it myself but i don't really have the equipment.

 

 

you don't have the equipment? .

 

Two bits of wire and a couple of spade connectors .

[gti_al 1]

hhmm... What power source would one use? (can you tell i'm not very good with electrical things? )

 

Does your car idle fine when cold but revs just rise and rise as it warms up? That is what I'd expect from a SAD issue...

 

Rob

 

P.S. They vary but some do need a touch of throttle for about 10seconds after starting to keep them going. After this period they should idle fine.

 

I find that on cold mornings it is really hard to get it to run... I'll turn the key and even with a bootful of accelerator it just dies. Often it takes 5+ goes to get it to run - then it still needs accelerator for a minute or two until it idles by itself.

Edited August 7, 2006 by gti_al

[Rob_the_Sparky 9]

Power source: car battery - This is all the car does in reality, not exactly sophisticated!

 

Minutes is too much, I wonder if your idle screw has been wound in too far to attempt to bring down the idle when hot?

 

Rob

 

P.S. There are alternatives that people have used (PeterT is one I think) that are a simple switch on the dash to open/close a valve. You then can have a manually controlled SAD.

[gti_al 1]

The idle screw is fully in... I'll try hooking the SADs up to a battery tomorrow, (i don't know why i thought that would be bad for them) but i suspect they are both shagged.

[Rob_the_Sparky 9]

Idle screw fully in isn't right and may well explain the problems when cold. IMHO the SAD is not a god bit of design, it is crude at best. If stuck I'd replace it with something easier to get hold of in Oz.

[gti_al 1]

I agree rob. No matter what i try it doesn't want to work... It seemed to close up fully when i did the test, although it took a lot longer than it should of. When i got home last night (after sitting in traffic for over an hour) it was idling at 600ish rpm, and would stall without revs. So i wound the screw out to bring it up to 1000rpm, yet it still didn't want to start today. Then when it did it waited a few minutes, when back up to 1500 and stayed there while i did the 15 minute drive to work...

 

I suspect this SAD isn't working right, so i'll try and find something in a scrapyard that will work better. i appreciate the replies though - my mechanic gave up and told me to fix it, and i need all the help possible...

Edited August 9, 2006 by gti_al

[Rob_the_Sparky 9]

Well the idle is controlled/can be affected by quite a few things:

 

Ignition timing

Throttle plate end stop

Idle adjust screw

Idle switch

AFM mixture adjust

etc.

 

If someon has been adjusting things to try to fix what is actually a SAD problem then things could be all over the place, hence thinking that the idle screw is wound too far in. It is normally the first thing to use if idle is too high.

 

600rpm idle when warm suggests that the SAD does at least sometimes close. From the way the idles drops on mine I'd guess the SAD is normally closing in a few minutes, certainly less than 5 (and too early!). If the engine did idle at 600rpm then I'd suggest that it is set-up pretty well, most struggle to idle at higher revs than that!

 

You could try disconnecting the SAD connector and see if this changes anything. If not then the SAD certainly isn't always closing.

 

You could also take a look at the connector and see if the pins are OK, sometimes one pin can get pushed back so not make contact even with the connector on. If it were like this then clearly the SAD would not close. You caould also check that with the engine running that you get 12V at this connector.

 

Rob