Replacement For Sad

[shepherdfte 0]

I just got round to replacing my SAD with a little solenoid valve off a ford EFI system. There was about 4 in my local scrappy, so that's nice. £4.

 

Looks like this:

 

http://img430.imageshack.us/img430/941/imgp19158sr.jpg

 

And here it is next to the SAD for scale:

 

http://img520.imageshack.us/img520/6910/imgp19165mf.jpg

 

Much nicer than the SAD as I can control it from a switch, which means no waiting for the SAD to open on a cold morning to get it to idle, and I KNOW it's closed when I want to tune the (hot) engine.

 

Basically just mounted it on the slam panel with a pipe from the normal SAD take-off direct to the plenum SAD inlet. The valve is only about 4mm diameter, so gives about a 400rpm rev rise without needing any sleeving or anything. Just needed 12v applying when you want it open (very low amp draw and very quiet), and no volts when closed. I just ran it to a switch on my rally panel, with the feed coming from the 'live with ign' supply in case I forget to turn it off one day!

 

Looks like this in the bay:

http://img502.imageshack.us/img502/9189/imgp19189us.jpg

http://img502.imageshack.us/img502/2352/imgp19197nc.jpg

http://img166.imageshack.us/img166/2140/imgp19208it.jpg

 

 

Very happy.

 

Andy

[DaveK 0]

Very clever dude, nice thinking. I always felt the SAD's were dodgey on the 205's

 

I sometimes get abit suspect that mine isnt working, then other times that it is...i really should check it along with the 100 other things

[Pug_101 0]

Excellent idea.

Now fit it to a timer or use a temp switch and dump the dash switch, and it's perfect for us forgetful fools

[shepherdfte 0]

Excellent idea.

Now fit it to a timer or use a temp switch and dump the dash switch, and it's perfect for us forgetful fools

Well, technically if you wired it direct to the SAD wiring I think you would achieve that. Plus, you tend to notice the high idle once warm.

 

Actually, on the way to work this morning, I flelt it was not quite raising the idle enough - I might swap it for one with a bigger bore, although it surprised me just how much the engine's natural rpm does change as it gets hot. An idle of about 900 with the new valve open (cold), became 1700 when hot, which gave 1200 with the valve shut = too high. So perhaps bigger bore or just two of them.

 

Out of interest, does anybody know exactly what the engine temp sensor does to the FUELING when the engine is cold? Richen it I suppose?

[petert 554]

Along the same idea, but for aftermarket ECU's, have you seen one of these?

 

 

 

You can plumb it in place of the SAD and have full idle control.

[jackherer 543]

Out of interest, does anybody know exactly what the engine temp sensor does to the FUELING when the engine is cold? Richen it I suppose?

 

yeah injector duration is scaled right up based on the input from the coolant temp sensor.

[shepherdfte 0]

yeah injector duration is scaled right up based on the input from the coolant temp sensor.

Just wondered, as my car has lately been producing rather more power cold/luke warm than it does hot. Still does it with the new SAD replacement.

 

Really fit cold, a bit 'flat' once hot. Mid-range especially, but top end too.

 

Perhaps suggests I'm a bit lean the rest of the time?

 

Out of interest, if I disconnect the (new) colant temp sensor, would the ECU see that as

 

1) always hot

2) always cold

3) fault

 

??

 

)

[richsmells 2]

I think it sees it as always cold hence the associated crap mpg.

 

Great idea by the way!

[shepherdfte 0]

I think it sees it as always cold hence the associated crap mpg.

 

Great idea by the way!

 

well, I do get crap mpg (about 23 at best), despite a notionally fit engine. But I'm gonna do a whole post on what the hell I need to do to tune it once I've sorted my suspension! Doubt it thinks it always cold though - I fitted a new sensor not long ago.

[gti_al 1]

Thanks for posting that - my sad has me ready to kill the car, as none i have tried close properly. I have been running with a cable-tied kink in the hose to the t/b just to make it idle.

 

I might have a crack at this next, as it sounds like an excellent fix.

[jackherer 543]

if the ecu coolant temp sensor is disconnected the ecu believes the coolant to be fully cold (-40deg C or something) and adds way too much fuel.

[Ahl 4]

Well, technically if you wired it direct to the SAD wiring I think you would achieve that. Plus, you tend to notice the high idle once warm.

Unfortunately, it doesn't work like that. The wire to the sad is just a power feed that heats up the internal bimetallic strip and causes it to slowly close when the engine is running. Its not a timed supply.

[shepherdfte 0]

Unfortunately, it doesn't work like that. The wire to the sad is just a power feed that heats up the internal bimetallic strip and causes it to slowly close when the engine is running. Its not a timed supply.

 

Ah yes - I knew that. Doh.

 

[madspikes 41 1 Cars]

Or you could get really technical and use a PIC microcontroller to sense RPM and water temp and decide if the valve needed to be open or not. Well, thats the idea I had over the weekend.

[shepherdfte 0]

Or you could get really technical and use a PIC microcontroller to sense RPM and water temp and decide if the valve needed to be open or not. Well, thats the idea I had over the weekend.

Yes, you could......

[cybernck 400 1 Cars]

a late reply but... could this be used as an idle valve for custom throttle bodied engines?

[TVH 0]

What year/model is that solenoid from? I want one too! Simple fast idle solution for us Megasquirters

[Rob_the_Sparky 9]

Also where did you get suitable pipe reducerds from, the size of the pipe to/from the SAD looks much bigger than the pipe you are using and I can't see in the photos how you have handled it.

 

Rob

[24seven 104]

what's SAD short for?

[petert 554]

a late reply but... could this be used as an idle valve for custom throttle bodied engines?

 

The one I posted can be. Note the idle stepper motor on the side. I shouldn't have posted soemthing to scale off. It's quite small. However, you usually don't need a stepper motor with throttle bodies.

[Butler 0]

Supplementary Air Device

[24seven 104]

ahhh. this topic now makes sense .

[Rob_the_Sparky 9]

The one I posted can be. Note the idle stepper motor on the side. I shouldn't have posted soemthing to scale off. It's quite small. However, you usually don't need a stepper motor with throttle bodies.

 

OK what is that off then? Something Ford(!) but what?

 

Rob

 

P.S. this is one useful thread...

[TVH 0]

Also where did you get suitable pipe reducerds from, the size of the pipe to/from the SAD looks much bigger than the pipe you are using and I can't see in the photos how you have handled it.

 

Rob

 

Looks like he used first a hose that fits the solenoid, then another hose on top of it. This is how I reduce / enlarge hose ends anyway

[Rob_the_Sparky 9]

That sounds far too easy!

 

Thanks

 

Rob