What would happen if I undo these bolts?

[empsburna]

Put the tools down, take the **** in a tin back and just drive it.

If it breaks give it to a nice man with a room full of spanners and a nice pretty ramp and X amount of years of knowledge.

[gazzb]

Originally Posted by cooper1200

what do u mean u have set the idle at around 1200... the idle isnt adjustable as it is ecu controled.
that screw on the throttle body that everyone keeps thinking is an idle screw is a back stop for the throttle cam and shouldnt be touched ever.

coop

OK so what does it do? as ive been spinning that round and round.. it definatly alters the idle speed as it was around 800 and now its 1200...
When it does try and stall it now only drops to 800 instead of 400..
If that makes sense :S

[418sld]

The compressions should certainly all be similar, from memory the actual figure is about 150-160psi but the main thing is for them to be even. Did you hold the throttle open when cranking? This is the correct method & makes quite a difference. Try checking it then pour a little oil into the bore & recheck - If the figures increase then you have worn piston rings but if not it may be poorly sealing valves. Don't worry about the oil, it will soon burn off.

[gazzb]

Originally Posted by 418sld

The compressions should certainly all be similar, from memory the actual figure is about 150-160psi but the main thing is for them to be even. Did you hold the throttle open when cranking? This is the correct method & makes quite a difference. Try checking it then pour a little oil into the bore & recheck - If the figures increase then you have worn piston rings but if not it may be poorly sealing valves. Don't worry about the oil, it will soon burn off.

Ah no.. I forgot about holding open the throttle!
Will have to try it again next week.

any ideas on what I should turn this little valve to now?

[PoorDriver]

The first thing to check when the car is running poorly are the plugs. My 416 tourer's had gaps of at least 2mm when I bought it. It was an EBAY job for only 127 quid coz of a duff water pump & very poor running, and that and the new pump I fixed in half an afternoon. The head gasket lasted another 6 months! Clean and re-gap the plugs.

[gazzb]

see previous post.. New Plugs and leads.. gapped properly before I put them in.
I have a problem with my alarm and air con as well so perhaps my whole electrics are screwed.. So maybe the ECU is the actual problem :S

[cooper1200]

that screw u turned is the stop for the throttle cam it is carefully set and should never ever be moved as i said. havent got a clue how u can get it back to where it was. I guess the best thing u can do is take it to a rover garage and get someone that might know how it should be set.

coop

[cooper1200]

i have no idea what u r trying to achive here the thread started off withu asking if u could undo the camshaft cover bolts. all of a sudden were on poor running and air con issues.

poor idle speed has nothing to do with tappets. why r u worrying about compresstion ratios? have u lost performance rather than just rough idle??? is it chucking out blue /white smoke? r u loosing coolent? if no to all thoes questions dont worry about ya comprestion all ur doing is confusing ya self.

there r lots of things that could lead to a rough idle from incorrect /dirty plugs to dodgy leads to falty sensor somewhere. u need to start at the begining and work ya way through logicaly.

i dont mean to be negative but moden car engines r a compleatly different kettle of fish to what they used to be 15 years ago. one tiny little fault can cause all sorts of symptoms and needs someone used to dealing with these engines to diagnose correctly.

by all means ask questions and im sure everyone will do thier best to answer help and advise.

coop

[matrix MG]

mine is now unbelivably quiet, no rattles or tappets at all.
had the head gasket replaced, changed the coolant, changed the oil (twice) and used slick 50,
new exhaust so it's a proper sealed system again.

now starts from cold like it's only been stopped 5 minutes. pulls like a train from cold too.