8V cutting out

[MKII 8V Nut]

Hi , I have a MKII 8 V Digi model and it has an intermittant cutting out problem, I have tried a new Idle valve but it hasent fixed the problem.
It idles fine on start up but when you rev it the car either drops to 500RPM and then kicks up the revs or drops it which then cuts the engine out.
Could it be airflow meter or fuel problem. Other then that minor problem the car flies!!

[Mr Blue]

an air leak maybe? I dont see how ISV's can fail, just give it a clean out with WD40.

Look at the oil breather which is ontop of the rocker cover. this should have a rubber grommet that seals the two together. These normaly ware and end up inside the rocker cover. Replace if needed.

check your leads, plugs dizzy cap and rotor arm while your at it

[MKII 8V Nut]

I have changed the dizzy,spark plugs and rotor. But the breather pipe is worn and cracked where air can leak. Could this be the cause of the problem? is there anything else that could cause it like the air flow meter?

[...joe]

also it might be worth taking your throttle body off and giving it a good clean out with brake cleaner as sometimes they can get all sh!tty. but if your breather pipe is worn/cracked i'd do that first as its only a small bit of hose to replace.

[MKII 8V Nut]

Cheers for your help I will try those two and see what happens.

[Veedubgt18v]

this will be the throttle microswitches, they arent serviceable so you have to get them from vw only or a scrappy. they are on the throttle and tell the ecu that it is open all the way or shut. check the wiring hasnt fallen out cos the get brittle from the heat from the manifolds.
its the little plug dirctly behind the throttle on a little mounting plate