Sad Problems ( I Suspect )

[BeN9o 0]

Hi everyone,

 

So my problem goes like this, i have a 1.6, with a fair few mods done to it (engine mods) like kent cam and uprated pully, and i know this would give it a bit of a dodgy idle, and ive read in other threads about the SAD causing a dodgy startup, and this is the case with me aswell, but even if i let it warm up before driving, it still wants to stall, i can be driving for 20 mins and when i pull up to a traffic light and let the revs drop to quickly it will still stall, unless of course i keep it in gear right down to under 1k revs then clutch in and it cant drop enough to stall.

 

Is this the SAD not turning off or is it something more sinister? I have a 1.9 aswell which ive already removed the SAD from ( its for spares atm), i have yet to get to the one in the 1.6 as i havnt had the time yet as its my daily runner to and from work.

 

Any help would be appreciated!

[DamirGTI 344]

If the SAD doesn't turn off it'll be oposite of that description this sounds more like air leak somewhere around inlet/SAD pipework .. so id start from there .. rather common breakdown point is on the "S" pipe which goes from the SAD on the bottom of the inlet manifold , to check this out - remove the top SAD pipe which is connected on the big air inlet pipe , stick the end of this the top SAD pipe in your mouth and blow inside .. while doing so run your hand around the bottom of the inlet manifold , if the pipe is perished you'll hear and feel the air coming out ..

 

For the rest of the inlet system , remove the top air feed pipe , start the engine and block the AFM inlet side with your hand while the engine works , by doing so it should stall just few seconds after you block the AFM , if it continues to work (roughly but still running) then theres a leak somewhere down from the AFM (often when theres a leak present and when you block the AFM you'll hear whistling sound from the leaking area ..)

 

Damir

Edited November 1, 2009 by DamirGTI

[BeN9o 0]

thanks for the help Damir, i'll try this as soon as possible, unfortunatly is raining right now, but i'll let you know how it goes!

 

Would a leak be the cause of it stalling at traffic lights and such?

[DamirGTI 344]

Would a leak be the cause of it stalling at traffic lights and such?

 

Yes , does the engine idle without the need for pressing the acc. pedal ? if not id bet on air leak .. SAD do couses problems but then the engine usually idles at very low or too high rmp. , or the idle speed is unstable , but it doesn't need pressing the acc. pedal in order to keep it running (i.e. if you let the foot of the acc. pedal it stalls and dies) ..

 

Could be a fair few other things though , but as said id start with checking for air leaks first , if that's fine report back and we'll stretch investigation further on other stuff ..

 

Damir

[BeN9o 0]

ok, so i did as you suggested, i took off SAD pipe and blew into it, and there was a noise, tried to figure out where it was coming from and its actually coming from the throttle body, where i took the air inlet pipe off leading from the afm, is this right? when i put my hand over and covered the throttle body, i could hear air from somewhere and when i put my ear close to the oil filler cap, where the breather pipe connects it sounded very much like the noise was coming from in there :/

 

This all sounds very peculiar!

 

Also when i put my hand over the AFM disconnected from the filter, it was running very lumpy but im not sure if this was because i didnt have my hand fully over it as theres an odd bend in the plastic connecting to the AFM as if someones pushed it in, best way to imagine it, is if you imagine a plastic cup, and just pushing one of the sides at the top in.

[Nrj 0]

What does SAD mean?

 

cheers.

[BeN9o 0]

SAD means supplementary air device, also known as a cold start valve

[DamirGTI 344]

ok, so i did as you suggested, i took off SAD pipe and blew into it, and there was a noise, tried to figure out where it was coming from and its actually coming from the throttle body, where i took the air inlet pipe off leading from the afm, is this right? when i put my hand over and covered the throttle body, i could hear air from somewhere and when i put my ear close to the oil filler cap, where the breather pipe connects it sounded very much like the noise was coming from in there :/

 

This all sounds very peculiar!

 

Also when i put my hand over the AFM disconnected from the filter, it was running very lumpy but im not sure if this was because i didnt have my hand fully over it as theres an odd bend in the plastic connecting to the AFM as if someones pushed it in, best way to imagine it, is if you imagine a plastic cup, and just pushing one of the sides at the top in.

 

This SAD pipe usually cracks at 90deg bend , which is roughly down under the filler cap , and on the end where is connected on the inlet manifold .. You will hear blowing , and this is normal , but blowing inside the inlet manifold only .. if you hear hissing outwards the inlet manifold when you plug up the throttle body and outlet for the vacuum servo unit then it'll be one of the SAD pipes cracked .. or even a blown inlet manifold gasket ..

 

If it was running when you plugged the AFM completely then theres something wrong , i.e. you most certainly have an air leak somewhere if it works with the AFM inlet blocked .. don't be afraid because of the bottom air pipe odd bending ! it'll do so when you plug the AFM anyway , just block it completely and wait for a few seconds if the car will stall and shut down , like it should if it's everything sound if theres no air leaks on the inlet system ..

 

Also you can try testing this with the can of easy start spray – start the engine and start spraying all around the joints on the inlet stream from the AFM outlet side till the head , if the revs start to increase when you apply the spray on particular area that'll be the leaking point

 

Damir

Edited November 3, 2009 by DamirGTI

[cybernck 403 1 Cars]

http://www.205gtidrivers.com/articles/e3-sad.html

[petert 601]

It could also mean the idle mixture is too lean. Give the screw in AFM a fiddle, or more precisely, set the mixture to around 13:1.

 

You can adjust the warm up time on the SAD, but after 20minutes it would be well and truly open regardless of the setting.

[BeN9o 0]

I've read the sad article already cybernck, i know its working, so the tests on that don't affect this problem, thanks anyways.

 

Petert: how can i accuratly set the mixture to 13:1? im hoping to get a good look at it tomoro after work, where i can take things out and move things around to have a closer look at the pipes, especially the one under the inlet mani, would i turn the AFM screw when its running? like would i hear the difference as i do it?

 

Thanks for everyones comments

[petert 601]

Petert: how can i accuratly set the mixture to 13:1?

 

Hook up an AFR meter. You'll need to increase the idle speed slightly however, as you won't get an accurate reading at normal idle speeds if you place the sensor in the tailpipe.

[BeN9o 0]

I think it might be the mixture, cause i cant find a leak at all, the inlet mani pipe seems fine no air coming out and no hissing at all when i blew into the SAD pipe, i also took the AFM intake pipe off and put my hand over and it stalled this time :/

 

i temporarily put a green air cotton filter on, (i had it lying around) and it seems to idle better right now, but it still will stall if i let the revs drop too much.

 

where abouts can i get an AFR meter from? do garages do it? as i know the people at my local garage quite well, and ive got my M.o.T coming up this month.

 

Thanks for the help

[DamirGTI 344]

Dunno if all the garages have AFR meter , if not ask at the MOT station and let them hook up the car on AFR meter for you .. then all you need to do is to tweak the AFM screw inside/outside ..

 

Anyway , worth checking the AFM itself , pop the black plastic cover off and look inside , you'll see small square plate with black carbon track ... now take a good look at this the black carbon track if theres any white areas/spots on the black surface or if the surface is rough with grooves .. particularly at the beginning of the track (from the area where the wiper arm rest till the middle .. as this is the part where it mostly wears out ..) .. this can lead to stalling as well .. if it isn't seriously worn it can be rectified by re-tracking (i have a doc. how to test check and re-track the AFM so if you want it please give me your email and i'll send you this doc. ..)

 

If it's fine , and if adjusting the AFM mixture screw doesn't help it might be good idea to book the rolling road session and let them re-set the air fuel mixture on all the rev range .. and ignition timing as well ...

 

As for idle mixture screw , on all 1.9 AFM's which i've came across the idle mixture screw was preset from 7 up to 8 turns from fully inside ... and adjusted like this i've always passed MOT sniff test .. though you can adjust it roughly "by ear" (however you need the car idling for this) , turn the screw all the way inside and then back it out 5 turns , start the engine and start turning the screw (slowly) further out few turns and then back inside , turn slowly till you notice the engine starts running rough , stop there and back off the screw two turns out from this position .. but this'll be just a rough adjustment .. (just to note -> turning the screw inside = rich idle mixture , turning the screw outside = lean idle mixture)

 

Damir

Edited November 6, 2009 by DamirGTI

[BeN9o 0]

bit of an update on this, i have yet to take it to get the AFR reading and tweaking done (although im probably going to a rolling road this month to get it re-done)

 

I recently got my hands on a 1.6 specific k&n filter, so after an hour or so of fiddling and moving stuff around, i managed to get the filter in place, but when i started the car it went straight to 3k revs and stayed there :/

 

i squeezed the sad pipe and it wasnt on as the car was still warm from going to my parents house, so it was running at 3k on its own!

 

i decided to drive it to see if it just needed running in and on a very short journey (about a mile) i got the STOP light up, and saw the temp was up right up, then the low coolant light came on. I got back home, put a bit more coolant in, went out and ragged the hell out of it, then for a test i put the clutch in doing about 30, and the revs dropped right down and the car stalled.

 

So at least im back to having the old problem rather than this new one!

 

Any ideas why that happend?

 

i'll post back here after reporting back from the mixture tweaking

[DamirGTI 344]

Check coolant and oil for signs of oil/water contamination , take good look around the engine if you can spot coolant leak from hoses/expansion bottle etc. and perform compression test asap ... and don't drive the car in the meanwhile (just short trip down to the local garage for compression test if you don't have compression tester at home ..) until you find out cause of overheating ..

 

Damir

Edited November 17, 2009 by DamirGTI