Sad Valve Questions

[Larawin 0]

Finally, got my engine running with the help of a friend. One of the things we found was that my SAD valve is working but faulty.

 

The SAD valve does close as the engine heats up but it is still letting air through . The idle is stable at 1750 rpm, when you close the inlet to the sad valve off it drops to 1100 rpm. I have 2 and they both do the same thing.

 

When we took one off the the disk close when blowing through one end it was easy to get air through to the other side, is this normal or should they close off completely airtight when they are shut. Our guess is that the seal are perished inside and is letting air through.

 

All of the pipes connecting them are completely airtight. If this is the case where can you get one? i bought one from Classic Peugeot Spares and it doesn't work.

[ATK 137 1 Cars]

Just adjust the idle speed a touch to accomodate, 1000 rpm when sad closed

[Larawin 0]

Just adjust the idle speed a touch to accomodate, 1000 rpm when sad closed

 

I have, when the engine is getting warm and the SAD is close the idle screw needs to be all the way in or it is reivng at 2k+ Wound all the way in it is idleing at 1750

 

But from cold it needs to be wound out to allow more air in or it wont start

[welshpug 1,627]

sounds like the throttle stop needs setting and the mixture too rich

[ATK 137 1 Cars]

Needs a proper setup then. Follow this:

 

 

Strip all the pipework out from the manifold back, take off all pipes etc. Take off the cold start valve, AFM, throttle body, air filter housing etc. Clean them all out with carb cleaner etc and refit making sure everything is tight and no holes or leaks etc.

 

Then try setting it up as follows (this is assuming your other components spark plugs fuel pump etc are all good):

 

1. warm engine up (until rad fan kicks in) and stop

 

2. turn AFM air bypass screw fully out (weaken mixture)

 

3. turn throttle air screw fully in (Larger screw on the throttle body)

 

4. Unscrew throttle stop screw so the throttle plate only just about 'clinks' against it when returning to rest position. start engine and set throttle stop screw (smaller screw on throttle body) to 600rpm (650rpm on 1.6)

 

5. turn throttle air screw out until RPM achieves required idle speed (900rpm +/-50rpm)

 

6. richen the mixture on the AFM by turning the screw in until the desired CO reading is achieved (1% - 2%) which will raise the RPM

 

7. turn the throttle air screw in until RPM is lowered back down to required idle speed in step 5

 

8. stop engine and adjust Throttle position sensor (on side of throttle body - rotates) to idle switch stop position (pin 2 and 18 continuity on a multimeter). Best way to get this done roughly is that to turn the TPS on the side of the throttle body so it just clicks as the throttle returns to rest.

 

Then set your ignition timing. don't bother with a light, wind the dizzy until it pinks in a low gear up a hill, then back it off slightly. You might need to wind the air screw in or out after doing the ignition timing.

 

If idle is still high either your ignition timing is too far advanced, you have an air leak or your cold start valve (SAD) is not closing up still. You should be aiming for around 1400rpm idle when cold and 950rpm when warm. I set mine to 1000rpm when warm as it drops to 950 due to electrical load when lights fan etc is on.

 

 

Best bet is to a buy a Haynes manual from Ebay for a fiver if you plan to work on the car yourself and keep it.

 

Good luck!

[Larawin 0]

Ill try this in the week sometime, thanks for all the repsonse

 

Is the SAD valve supposed to be completly air tight when shut?

[ATK 137 1 Cars]

Dont think it really matters as long as the idle is right, its only airflow

[Larawin 0]

Where abouts is the air bypass screw on the Airflow meter?

[welshpug 1,627]

its not on the afm, its on the throttle body

[ATK 137 1 Cars]

Airflow meter screw on top of afm is for adjusting CO / mixture. Might be under a little black cap. Hex screw.

 

Aim for 1.5% or below for afm

Edited July 4, 2016 by ATK