vauxhall corsa problems

hi everyone
im having problems with my vauxhall corsa 1.2 sxi.
i have changed the head gasket due to ut blowing but now when i start the car it is rough on idle but when reved above 800rpm its fine.
it idels rough like it about to turn off but keeps going but drives perfect pull normal.
i have changed oil, oil filter, new spark plugs and oil but no luck.
can any one help.
also does anyone have a pdf on timing marks.

Reply 1

Kre

Ah... my good old SXi had to have its head changed a few months back too. Rough idling could be caused by bad spark plugs or clogged filters, but since you've replaced them, have you thought about replacing your vacuum hose? If it's loose or broken it can cause rough idling.
That should fix it since Vauxhall Corsas at that age usually have timing chains. If it had a cam belt, it could be jumping a tooth which leads to the rough idling. However, I don't think any Vauxhall Corsas at that age and engine had cam belts.

Reply 2

455409

ahhh corsas. worlds most unreliable car ever. why do people still buy these?

Reply 3

Camoxide

Original post by james1211

ahhh corsas. worlds most unreliable car ever. why do people still buy these?

So dey can sho it off to der class mates brah and rev da fookin redline.

*attempt at chav speak.

Reply 4

JC.

If it's idling below 800rpm that suggests that the idle speed is set too low?

Reply 5

CurlyBen

Original post by JC.

If it's idling below 800rpm that suggests that the idle speed is set too low?

Or part of the idle control system (sensors/actuators/ECU, depending on age) are faulty - I was under the impression most electronically controlled engines don't have any means to alter the idle speed.

Reply 6

JC.

Original post by CurlyBen

If we're talking about something in production today, then you're 100% on the money.
Having said that, I did have an early 90's volvo that had an idle adjuster screw on it?
Cars of that age are something of a half breed - lost in the void between an old fashioned carb, points and dizzy technology and the 4 wheeled computers that are sold today, eh?

Reply 7

CurlyBen

I've never worked on early 90s cars but I've no doubt there's some weird and wonderful hybrids running around. I know my '97 Peugeots both had fixed idle speeds.

If you think cars are bad, you should see a modern tractor! Where I work everything post-2008 has computer screens which can give you all kinds of info, from hydraulic oil pressure to instantaneous fuel usage to acreage. Worse, the clutch packs are electro-hydraulic so if it detects a fault it doesn't like it simply won't let you engage drive, which can be bloody scary when working alongside a harvester or on the road. The harvesters are even worse, I've not used one but they've got multiple touch screens and joysticks which control everything. Even the key doesn't start the engine, only the computer - you press a button on the screen to start and stop the engine.