Lumpy engine

[KarlP]

I bought a 1 Liter, 98 Corsa GLS 3dr the other week. At low revs (under 2000) the car seems to vibrate, we thought (me and my dad) it was just engine mounts but its not. The idle was lumpy and seems to missfire slightly at all revs.
So today my dad put in new spark plugs, new air filter, and fuel filter, then cleaned the throttle body with carb cleaner.
The car will start but only with the throttle fully depressed. It will then idle but it hunts badly. The rpm goes from about 800-1000 constantly up and down with a putt putt sound from the exhaust and this seems to be worse since we cleaned the throttle body.
Any ideas guys? Please
Thanks Karl.

[Octane2097]

what happens if you just rev it to the redline and then let it idle?

could be clogged intake or exhuast
or maybe fuel pump fault
also could be faulty dis pack or the idle control valve

could always try and get it hooked up to a computer and see what error codes come up
even if ur ECU light hasnt come on, still might be a fault with a sensor or sumthing
il have a poke about n see if i can find out what it might be for ya

[KarlP]

Thank you, its now sorted. It was the EGR valve, was stuck open with a piece of carbon that must of come loose when we cleaned out the throttle body, but we would still like to find out about the vibration at low revs, any clues guys?

[Octane2097]

possebly the timeing is slightly out
but the 1.0i do rattle about a bit mine was the same i think thats just how they are pal

[KarlP]

Oh thanks mate. Its not that big of a problem so looks like it will just have to be lived with. Thanks.

[Octane2097]

just give it some POWER!!!
its only vibrates usualy at low revs so nail it and you wont feel it
thats what i did!

[jcorsa]

hi mate. i bought a 1l corsa a couple of weeks ago and had the same problem. i replaced the egr valve and all fine now. as for ticking over mines the same . just give it some s**t.

[KarlP]

just learning to drive so i dont have the balls to floor it

[Octane2097]

oh belive me it wont do alot when you do floor it!
i remember when i 1st got my 1.0 corsa
even on my provisional i had it on the dual caridgeway giving it the beans!

[KarlP]

Well i mean....put a little bit of revs in it

[Octane2097]

take it on a dual carridgeway then
only place you can really drive at 70 legaly on a provisonal!

altho its a 1.0i they arnt exacly fast but given enough road you could get 100mph
ilegaly of course!
since petrol costs a fortune these days, drive steady you will be laffing with 50mpg!