Mk2 scirocco 1.8 8v 1990 SPLUTTER/ROUGH ON IDLE

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MattR2020
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Location: Wolverhampton

Mk2 scirocco 1.8 8v 1990 SPLUTTER/ROUGH ON IDLE

Post by MattR2020 »

Hey all. Well... I had a few issues unresolved piling up as this car is my daily runner couldn't afford time off work😃 oil leak behind oil filter housing, oil leak from rocker gasket down engine, leaking coolant from rad switch, leakin coolant from one engine switch around seal.. Possible fuel pump issues, overdue oil change inc oil filter change, inline fuel filter needed change (can only find one on this vehicle under hood) .. Whining fan belt (slight sound) ever since last one went and i changed it on side of road.
Oh spark plugs overdue a change inc two middle ones seized..
Also rusted an broken bulkhead where clutch cable heads through to peddle so excessive force on pedal was a no go.. So yeah along with all that my car had ticking noise from engine, came and went at random intervals an seemed to increase with acceloration i..e get faster. Then car started playin up big time, stuttering, loosin acceloration, jerkin.. Been drivin on a prayer basically :-( .. So been stranded until i nursed my car to garage an dropped it off.. Had almost all parts, dropped off at the garage with my car. My m8 at garage did it all.. Apparently pressure tested engine too to check if there was an issue with a cylinder but he never said there was so i assume thats okay. Got car back 3 days later.. He told me alternator on its way out, carbs rubber flange needs changin as its split an most likely need to change ignition leads too as some rusty, they old an screwed tbf. Im guessing there is a poor mixture of air, fuel and ignition due to poor leads. Drive it back that day seemed okay, at least better than it was.
So this week i changed the carb flange, HT (ignition) leads, had to screw off tops of sparks to make em fit and alternator after getting it refurbed.. Initially i had a K&N air filter on my weber 32/34 DTML carb, the oval shaped silver one but as this has no clamps it had got mega wobbly and decided i will revert back to origanal air intake as you can use the bracket on rocker an secure them much better... Idle i had aleady set to 800 RPM prior to all this and while doing the above i changed the choke, also set the choke to work as it should i.e. Closed in car, open on carb, pulled open choke in car, closed on carb etc...
After all this i figured id try turn it over, not been on for around 4 days the engine... Anyway, seems to be having a rough idle, trying to cut out on me and doing so if i took my foot off the pedal. Did manage to drive it around my carpark for a couple laps but decided to shut it off incase i do more damage.
All parts i ordered were from heritage parts so decent quality. Waiting on one piece to the puzzle which is some cardboard ducting, this will fit to intake manifold and attach to the airbox intake to supply warm air...
Im wondering whether this may be causing that rough start, drive etc the fact that its missing (i get the hose tomorrow so will try with it on)! Or maybe my car is just so damn used to the k&N air filter that the engine loves the extra air flow and thats why it struggled. Usually i put a small K&N oil catcher over the rockers breather which of course was not in place while i tested as now its connected to the original air intake box.
Not sure exactly how the vacuum on the air intake works either or if thats working as it should. I have the small air line from vacuum to the air box at back connected correctly (left hand side looking from above), i blanked off the 2nd as no need for it. My brake servo pipe seems good, also one outlet on there is blanked as usual and one leads to the vacuum on the dizzy cap as it should.

Maybe i need to check over carb but all seemed fine, its only 4 years old. I know there is a hidden screw on the weber for adjusting the fuel mix but never have i adjusted it as its a 1.8 and lot folks don't bother not to mention my car drove like a bat out of hell the past 4 years.

So yeah not im stuck as to what to do, seems ive done a lot and no resolve as of yet.

Any ideas welcome, sorry about the long read but i wanted to be detailed about it.

Go back to K&N air filter maybe? Fit ducting for hot air on plastic intake system? Adjust carb some how? Double check idle screw with all filters off?
Stumped dot com


mark1gls
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Re: Mk2 scirocco 1.8 8v 1990 SPLUTTER/ROUGH ON IDLE

Post by mark1gls »

Check the Ht leads are in the right order, 1,3,4,2 clockwise, No 1 should have a line marked on the edge of the dissy if you remove the cap.

Did you fit a new dissy cap, rotor arm and spark plugs when you changed the HT leads?

If you remove the air filter box will the car still start?


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