1.9 Suspected Sad Problem

[m_john_m 4]

Hi all,

 

i posted on here a good while ago about my car not ticking over. well my mate came down to give me a hand who is a diesel mechanic...... i know but he still knows alot more than me.

 

we took the throttle body off and gave it a good clean. it was minging!

 

we took the maf sensor off and gave it a good clean, again it was minging.

 

it now runs better but still wont tick over, sounds like its misfiring.

 

i have done a bit of research on here and some people have had the same problem, is the SAD easy to take off?

 

how do i clean it? brake cleaner? if this doesnt work then its going to a mechanics!

 

any help would be great! thanks

 

PS i have a haynes manual for it so hopefully that will help me tonight

[jackherer 543]

When you cleaned the throttle body did you clean the idle by pass screw? To have any chance of a stable idle you need to remove it and clean it until it shines.

 

However none of this is relevant if it is misfiring, the SAD and the idle bypass screw just let extra air in so can't cause a misfire.

 

You need to look at the ignition system or possibly fuelling, what do the spark plugs look like?

[Anthony 1,000]

If it sounds like it's missing are you sure that everything is in good order, there's no air leaks and the idle fuel mixture is in the right ballpark? If they're running excessively lean then they will sound like it's missing - aim for around 1% CO.

 

The SAD is located underneath the dizzy and access is a bit arkward, but not too bad. The SAD itself is often incorrectly blamed for idle problems by people that have mis-diagnosed the fault or who are just plain clueless - in my experience, the SAD is actually very reliable and rarely the cause of idle related issues.

[m_john_m 4]

Yes i took the screw out and gave it a clean, i will clean it yet again tonight to make it shine!

 

the spark plugs are brand new. The car is overfueling like mad as its banging from cold. how would i reduce the fueling?

 

about 4 of the breather pipes are damaged in some way or another. i taped them up (as a temp fix) to see if this would help but it didnt, Tonights job is to check/clean the SAD, if that doesnt help then i will take off all the damaged breather pipes and replace them. would the breathers make that much of a difference? im hoping so anyway lol

 

sorry for being a complete novice but you got to start somewhere!

 

any advice/tips that i can try tonight would be very helpful! iv not got much of a mechanical knowledge but iv been told they are easy to work on.

[welshpug 1,626]

Pull the rubber boot back on the afm connector, not uncommon to find the pins have worked loose.

 

actual mixture adjustment is done with the 5mm allen key in the afm, it bleeds air past the flap.

 

air screw is purely for idle speed adjustment once the throttle initial settings are done.

[PhilNW 40]

^{Try taking off the spark plug leads one by one to see if its a single cylinder problem or a general misfire}

[scbond 15 1 Cars]

Is the misfire only when you start from cold?

[m_john_m 4]

I can't keep it running to take out the sparks. I'm looking for some new breathers as mine are cracked. Could this cause a misfire??

I have never ran it warm as it always cuts out! I took the SAD valve off before and cleaned that, looked down it and I could see a pie shape, I think this is good asi read it on another post.

 

It's annoying that I can't get it to tick over as I can't do the timing :/ IV got a timing gun but can't do this until it's idling, is this right?

[m_john_m 4]

Has anyone got a recommendation for a dizzy cap and new leads? Looking on eBay and I can see pro spark, these good to use?

[welshpug 1,626]

They have no bearing on fuelling.

 

bosch was o.e for caps, bougicord for leads, have used beru leads which fit fine and come with both types of king lead

[Weser 30]

If its overfueling I would check the ecu coolant sensor. You can take it out and check the resistance values over a temperature range. Think the values are on here somewhere.

[scbond 15 1 Cars]

I can't keep it running to take out the sparks. I'm looking for some new breathers as mine are cracked. Could this cause a misfire??

I have never ran it warm as it always cuts out! I took the SAD valve off before and cleaned that, looked down it and I could see a pie shape, I think this is good asi read it on another post.

 

It's annoying that I can't get it to tick over as I can't do the timing :/ IV got a timing gun but can't do this until it's idling, is this right?

 

How big was the hole in the SAD? Can you post a pic looking through it?

 

As welshpug said, the cracked breathers won't cause a misfire. They'd usually just cause poor idling issues. You'll want to get them replaced anyway but they aren't the cause of your misfire.

Edited July 8, 2014 by scbond

[m_john_m 4]

They have no bearing on fuelling.

 

bosch was o.e for caps, bougicord for leads, have used beru leads which fit fine and come with both types of king lead

 

i know but i broke my dissy cap last night so it needs replacing.

 

what could cause it to not idle though? thats my main concern at the moment :/

 

i took the SAD off last night and could see a pie shape down the hole, didnt get a picture unfortunately. iv read that this is a good thing

 

how would i check the ecu coolant sensor?

 

sorry for being useless lol

[Slo 283 1 Cars]

Forget about the breathers, if anything cracked/split breathers would let air in causing it to idle like it was running on meths (high).

 

This does sound like the ecu temp sensor, its the blue one that screws into the side of the sad.

 

If the sad is working properly the pie will be out of sight when its cold and completely shut when its upto temperature.

[scbond 15 1 Cars]

 

i know but i broke my dissy cap last night so it needs replacing.

 

what could cause it to not idle though? thats my main concern at the moment :/

 

i took the SAD off last night and could see a pie shape down the hole, didnt get a picture unfortunately. iv read that this is a good thing

 

how would i check the ecu coolant sensor?

 

sorry for being useless lol

 

It really depends on how big that hole is. The small (8mm I think) nut on the SAD adjusts the starting position/size of the hole from cold. If the hole is too small then the engine will struggle to start and will run rough below 1,000 rpm until it begins to warm up. Seeing as checking this would cost you nothing, I'd start there. Then start looking at the coolant temperature sensor, AFM etc.

[m_john_m 4]

Ok thanks, I will see if this helps! Going to try again now.

 

I just want new breathers as mine are cracked and need replacing, I'll adjust that but to see if that helps, if not I will take it off and take pics of the inside for yous to see! Thanks again

[m_john_m 4]

 

Is that the nut that makes the hole bigger or smaller? When I undone the screw nothing seemed to happen.

 

 

There is the hole in the SAD, I stuck a screwdriver in and it seemed to spin around.

 

Stupidly I unplugged all of the HT leads from the dizzy and couldnt remember where they went, found some pics so I now know where they go.

 

Is the SAD working from what IV described and from the pics?

[Slo 283 1 Cars]

If its open when the engine is cold and closes when the engine is hot its working beyond telling you that there is nothing anyone can tell from a pic.

 

Warm it up off the car with a blow torch and see if it closes. You can use the kitchen hob if its gas.

 

Oh and see that blue sensor stuck on the side, thats the ecu temp sensor. If thats buggered or its wiring the ecu will make it overfuel.

Edited July 8, 2014 by Slo

[m_john_m 4]

If its open when the engine is cold and closes when the engine is hot its working beyond telling you that there is nothing anyone can tell from a pic.

 

Warm it up off the car with a blow torch and see if it closes. You can use the kitchen hob if its gas.

 

Oh and see that blue sensor stuck on the side, thats the ecu temp sensor. If thats buggered or its wiring the ecu will make it overfuel.

Any way of telling if it's broke?

[welshpug 1,626]

Plug it into a 12v source and check it after 5 and 10 minutes, the disc should rotate and close the hole.

 

I would not go waving a blowtorch at it...

 

 

However, as mentioned several times, it will NOT cause a misfire or over fuelling.

 

 

 

As for the blue ecu temperature sender check its resistance reading with a multimeter.

Edited July 8, 2014 by welshpug

[Anthony 1,000]

The SAD is open sufficiently in that picture for cold running - worse case it doesn't close would cause a high warm idle, not the issues you're seeing.

[m_john_m 4]

Plug it into a 12v source and check it after 5 and 10 minutes, the disc should rotate and close the hole.

I would not go waving a blowtorch at it...

However, as mentioned several times, it will NOT cause a misfire or over fuelling.

As for the blue ecu temperature sender check its resistance reading with a multimeter.

At the moment the misfire is not bothering me, it's the fact it won't tick over :/

[m_john_m 4]

God knows what's up with it!

[Weser 30]

Check the ecu temp sensor. Fueling issues will stop it idling. Plus its something else crossed off your list on checking. They can cause some real problems!

 

When you start it can you keep it running up the rev range? It just wont idle? If you can keep it running up the rev range a bit is it still sounding like its missing? If so you can get someone to help you check which one is missing by pulling lead off at a time?

 

If it is missing you will have trouble getting a decent idle I would have thought. Just checking the basics - you have definitely got a spark on each plug and compression on all cylinders?

[scbond 15 1 Cars]

The hole looks as though it's as small as possible. Undo the little nutting then the bolt should move from side to side slightly. It may help if you pass a screwdriver through the hole of the disc in the valve so you can push the disc and make the hole bigger. Do it gently and make the hole a bit bigger, hold it as it is with the screwdriver and then tighten the nut.

 

Mine had a cold starting misfire and this was my issue. After much hunting for a cause and solution Tom (on here) pointed me towards this and after a quick adjustment it started perfectly. It also turned out that my AFM was buggered though but that has more obvious symptoms that I was also getting.

 

There's no default adjustment setting for the SAD, it'll vary from engine to engine. Try the adjustment, then start and let the car warm up so you can do the usual setup for idling with the throttle position, idle screw etc. Then let it cool and try starting from cold to see if it's been successful.

Edited July 9, 2014 by scbond