Afm And Sad Testing

[starky5 18]

Hi,

 

Ive been searching the forum for the last hour or so and can only find topics suggesting to swap for a known good one to test. Surely there much be a way to test these without swapping them? I ask as i dont have access to a known good spare, i have a multimeter though and access to other testers if required!

 

My standard 1.9 8v runs lumpy when cold, it starts fine but is lumpy and jerky when cold so i would like to test the AFM and the SAD if possible to rule them out.

 

Thanks for any help.

 

On a separate random note, and i know it would be a lot of work, but wouldn't a FAQ section be quite good in the technical section with info on how to test components and the results you would hope for as well as the symptoms a faulty component would produce?

[chris205gtioliver 0]

To check my sad I took it off and connected it to 12v, looking into it, it slowly closed after a few minutes. Or when it's on the car and the car is cold, squeeze the pipe comming out of the sad and the car should either stall or struggle to idle, when hot and it's squeezed it shouldn't make any difference. Hope that helps with the sad.

[mickey_vista 0]

Hi,

 

Ive been searching the forum for the last hour or so and can only find topics suggesting to swap for a known good one to test. Surely there much be a way to test these without swapping them? I ask as i dont have access to a known good spare, i have a multimeter though and access to other testers if required!

 

My standard 1.9 8v runs lumpy when cold, it starts fine but is lumpy and jerky when cold so i would like to test the AFM and the SAD if possible to rule them out.

 

Thanks for any help.

 

On a separate random note, and i know it would be a lot of work, but wouldn't a FAQ section be quite good in the technical section with info on how to test components and the results you would hope for as well as the symptoms a faulty component would produce?

 

I tried testing the SAD on my 1.6 and although the diaphram seemed to be open (at least partially) when cold and closed as it heated up I decided to replace it anyway as the cold idling was so poor. What a difference the new one made! Excellent idling at about 1200 rpm when cold, dropping to 950 rpm when the engine's warmed up. I discovered that most non-Pug people refer to this device as an Idle Control Valve rather than a SAD. I got my new one through Intermotor (look up under Idle Control Valves on their online catalogue ). It only cost about £25 (2 years ago) and is a genuine Bosch part.

[starky5 18]

Ok i went to test the AFM and SAD this morning, i managed to test the AFM following a haynes manual and then it started raining! i think the SAD is ok though as i sat in the car and started it when it was cold. It started at a lumpy 1000 RMP for about 10-20 seconds then climbed to 1600 RMP and sat there quite well with the odd lump then slowly dropped to just above 1100 RPM over the next 5 mins. From what I've read this sounds about right?

 

The AFM tested ok there was only one reading which was too high according to my manual, the AFM plug to earth (M18-Earth) resistance should have been less than 1 ohm but I got a reading of 3.7 ohms. Does anyone know what affect this would have?

 

Im starting to think i could be an injector based problem as the SAD and AFM seem to be ok and the main problem is how jerky and juddery the car is when its cold. It always starts (when the batterys not flat!) when hot or cold and although lumpy when 1st started cold I'm guessing it could just be the ages of the car.

 

Any suggestions on what to check next would be appreciated as the car is a nightmare to drive when cold.

 

Thanks