Idling Too Fast

[shonkers 6]

With the brass idle screw turned right in, it shouldn't idle at all so you must have an additional air leak somewhere or the throttle butterfly isn't fully closing imo.

 

For the idle rpm to increase, there seems to be something signalling for more fuel as well, just additional air would make it struggle to idle due to a weaker mixture wouldn't it?

 

Is your SAD closing off when its warmed up? Squeeze the SAD hose to the pipe between the afm & tb once its warmed to see if it drops at all.

 

g

hope you dont mind if i hijack my thread back ha ha,i squeezed the sad hose and the idle speed did drop,it dropped even before it warmed up i presume that means the sad is working.i found the idle speed screw youre right mine is recessed and adjusted it its much better now.the thermostat was stuck shut so thats why the rad wasnt heating up so everythings circulating now and not pressurerising so that rules out the head gasket,but now with the fresh anti freeze in the water pump is leaking,obviously there wasnt the correct strength anti freeze or its degraded.now because the engine is a bit cranky in other words the big ends have gone im considering whipping the engine out doing the crank and the water pump at the same time what do you reckon?

[shonkers 6]

That's just it! I've set the stop screw as far back as it will go and the idle screw as far in and it makes no difference! Either air is getting in and I just can't find it or something else is amiss! Going in to battle with it again this evening so will report back, in the mean time any other ideas welcome!

a good way to check for air leaks is with engine running squirt wd40 over the intake hoses ,pipes, joints etc and see if the engine note sounds different or suddenly picks up

[pug_ham 242 3 Cars]

Please use puctuation in your posts when typing.

 

Bunching it all up like you have makes it difficult to read & also mkes it less likely you'll get a reply because it can take some deciphering to get your point across.

hope you dont mind if i hijack my thread back ha ha,i squeezed the sad hose and the idle speed did drop,it dropped even before it warmed up i presume that means the sad is working.

 

Squeezing the SAD hose when the engine is still warming up does show that it is open but not that it is working when the engine is warm & it should be closed, squeezing the hose with the engine warm shouldn't make any difference to the idle speed.

 

If it does then the SAD hasn't closed.

now because the engine is a bit cranky in other words the big ends have gone im considering whipping the engine out doing the crank and the water pump at the same time what do you reckon?

Why do you assume your big ends have now gone?

 

If you strip the engine to any level to do the crank bearings then whilst it's apart, you might as well replace the water pump with a new one if you have no history of it having been done in the life of the car, especially as they are under £20 new.

 

g

[mhyphenl 10 1 Cars]

After fiddling I found that, even though I had unscrewed the throttle position stop I hadn't loosened off the tps and so this was holding the butterfly open, loosen both and I've got the revs down to about 950 when warm, but the brass idle adjustment screw us still fully in and the engine light is still on when idleing! Fault code is saying mixture incorrect!! The most vague code in the book!

[pug_ham 242 3 Cars]

the engine light is still on when idleing! Fault code is saying mixture incorrect!! The most vague code in the book!

What code is it giving because I can't find mixture incorreect listed in my autodata?

 

What is vague about the mixture being incorrect, its either high, low or the lambda sensor is faulty giving a duff signal.

 

You need to plug it into an exhaust gas tester to see which it is.

 

g

[shonkers 6]

Please use puctuation in your posts when typing.

 

Bunching it all up like you have makes it difficult to read & also mkes it less likely you'll get a reply because it can take some deciphering to get your point across.

 

 

Squeezing the SAD hose when the engine is still warming up does show that it is open but not that it is working when the engine is warm & it should be closed, squeezing the hose with the engine warm shouldn't make any difference to the idle speed.

 

If it does then the SAD hasn't closed.

 

Why do you assume your big ends have now gone?

 

If you strip the engine to any level to do the crank bearings then whilst it's apart, you might as well replace the water pump with a new one if you have no history of it having been done in the life of the car, especially as they are under £20 new.

 

g

sorry about the bunching up ill try and keep it short and sweet ,ill squeeze sad hose when warm,and the big ends were really knocking quite bad when i first got it so went for quick fix and just changed the shells,it was a lot better but not really cured. anyway thanks for info ill let you know how i get on cheers

[mhyphenl 10 1 Cars]

OK getting there, all due to snippets of advice. Anyway, adjusted the throttle position screw and sensor to the absolute minimum and brass screw all the way in and sure enough, when cold, squeeze the SAD pipe and it died!! Never thought that starving my engine of air would feel so good

I've found that although the SAD was working to a point it was never closing fully which is probably why I couldn't get it to settle much when warm. The bolt on the SAD however seems to allow the setting of the initial position so I closed it off a bit too. That seems to give an idle of roughly 1100 on a quick test, not had chance to reconstruct everything yet though to get a warm idle. In terms of setup, on a Motronic it says that mixture setup is not possible as the ECU does it all. Is it just a case of getting the revs to 900 ish on tickover or do I still need to follow a set setup routine with a gas analyser.