Car not running properly since head change

[Jules 0]

Hi Guys,

 

Just had the head changed on my 16v C and it is not running right at all. I am guessing that the timing and CO will need to be adjusted and this should hopefully sort out the stuttering when I take my foot off the accelerator?

 

I did try to find a decent garage to get the timing and CO set and some of the questions I got were....."Are you sure you can adjust the CO on these cars?" !!!!!...and "The car might not be running right cause the timing belt has jumped a tooth"...lol. I am always nervous at the best of times letting anyone work on the car. Anyway, I think I have found a place to take the car to at the weekend.

 

The other problem is however that the revs are taking ages to drop. It has been like this since I got the car 7yr ago (and only now I show an interest in solving this!!!). Is this worse though due to the timing etc needing set, or could it be something else?

 

Julie

[h100vw 0]

Which 16V?

Gavin

[Jules 0]

Sorry....1.8 16v

[Baz2004 0]

 

The other problem is however that the revs are taking ages to drop.

 

Have you tried cleaning out your ISV and replacing the Idle control switch on the N/S of the head? (green and red wire as far as I remember)

 

I read before that the timing belts can jump a tooth or can be out by a tooth causing them to run like muck.

[h100vw 0]

I think the idle screw has wound it's way out. Or maybe the garage don't know how to set the tickover??

You need to warm the car up, 80degrees oil temp. Then disconnect the RED/BLACK wire by the coil. Adjust the tickover with the screw to about 850ish. Then reconnect the red/black.

Try that first before we set about your other snags.

Gavin

[wcrado 0]

if it's an uprated head, i.e ported and polished, you will be getting much more air into the combustion chamber, therefore the fuelling needs to be increased. very simply done, just adjusted on the metering head with an allan key. any competent garage should be able to hook it up to a computer and adjust it accurately. if they're worth their weight they should automatically adjust the tickover as well. if it is running lean, which it sounds like it is, it will be running lumpy as f*ck with a rough idle and very poor response. as for the revs taking ages to die, does your car have an uprated exhaust? hope this helps, even if i am stating the obvious

[Jules 0]

Seems to be running better today as last night my boyfriend turned the timing back a bit but the CO hasnt been touched yet. When idling it does sound lumpy through the exhaust but isnt stuttering like it was and definetely more power in it today.

 

It has a full stainless exhaust which was fitted a few year ago but I didnt notice any change in the speed the revs dropped from the standard exhaust system. Maybe I'm being too fussy though over the revs dropping thing as I'm always comparing it to my MK11 Golf Gti I had where the revs dropped really fast , but maybe in comparison the Corrado's are just like that? :roll:

 

Thanks for your help

[wcrado 0]

ok good, but please make sure you have the fuelling set properly by a garage with the proper equipment! they should hook it up to a computer via an exhaust probe and adjust it on the metering head. glad you had the timing set properly! that should have been done straight away! don't bother taking it to kwikfit or anything for godssake, just a respectable garage! i recently swapped my standard exhaust system for a milltek 4-branch manifold and full system, and ever since then the revs have been slow to drop, i noticed it straight away, so thats why i asked. must be down to a reduction in back pressure or summin. if it's not changed before the exhaust or after on yours then i dunno!

[Skimask 0]

Jules,

Book the car into Starperformance (details in suppliers section), and get them to do a rolling road tune. They specialise in tuning VW/Audi it may cost about £80 or so but it'll be worth it.

[Jules 0]

Yeah thanks I think I will do that. Its not that far from me anyway. I'd rather give them £80 and get the job done right, than give £50 to a dodgy backstreet garage down my way!