VW scirocco problems - montag

Hope somebody has had this as it is driving me nuts!

Got a D reg 1800 gt Scirocco which generally purrs. However there is a totally erratic fault. Every know and again the car cuts out. As you accelerate the engine lurchs and loses power. If you dip the clutch you can keep the engine running smoothly by hitting the gas but as soon as you let of the gas the engine dies. Very easy to start afterwards but will not drive, idles ok (sometimes!). if you leave it for a minute it will start ok and drive ok! You may be able to drive it ok for 20miles then go to the local shops and it lurches.

Totally random when it happens, the car either drives perfect or not at all, normally on the same journey.

Happens slightly more often going up hills but has happened on flat and downhill.

I have replaced today:

HT leads
rotor arm
vacuum hoses

Has had a recent fuel pump and air filter.

RAC blokey dismantled carb and cleaned jets.

Any ideas please before I go bald!!!!

Cheers all and stay happy
VW scirocco problems - Malcolm_L
Sounds like you\'ve changed everything that could cause this!

Sounds like fuel - you didn\'t mention fuel filter, if there is one have you changed it?

Could be something floating around in the carb and blocking off fuel - I\'d strip the carb down and clean everything, probably worth getting a repair kit and replacing seals, etc while you\'ve got it in bits.

VW scirocco problems - Drew20
could be an intermitent vacuum leak, the carb mounting flange might need replacing

is there any pattern to when the engine cuts, I might suggest carb icing, you can fix this by checking that a small cylindrical heater on the front of the carb works (next to the wax stat). on my golf this did not work properly as the carb earth had snapped off. on cold damp days the engine would die
VW scirocco problems - Peter D
HAs this car got an electric fuel pump ?? A guy came to me with a similair fault that always seem to happen on long right bends Yeap it was the fuel pump but it was a later model VW. Found it by using a scope across the pump and you could see the speed varying significantly. Regards Peter
VW scirocco problems - Adam Going (Tune-Up)
Check that the air intake control flap (in air cleaner intake) is operating correctly. Should provide hot air to carb when air cleaner is cold, warm air only when really hot. Excess cold air can ause carb icing - even in this wheather.

Also, VWs of this age are prone to silting up inside the fuel tank, often as a result of water ingress via corroded filler neck or rusting of the tank itself. Rubbish collects around fuel outlet, restricting flow. Temporary improvement possible by blowing back down supply line into tank, but just like Arnie, IT WILL BE BACK !!

Regards, Adam

Whatever is rightly done, however humble, is noble.
VW scirocco problems - montag
hey cheers all!!!

Just found that the breather pipe junction with the fuel feeder pipe has corroded and parted company, feeder pipe is ok but junction very corroded so I reckon this might be it!! Oh well 100 mile round trip tomorrow to get another one !

Thanks for the help!!

remember that this is yet another example of something!
VW scirocco problems - ajit
Sorry, I saw this thread too late, I had the same problem on my Scirro and went up the same expensive alley. Yes it was corroded fuel line
Scirocco woes... still - montag
Posted a while back concerning my MK2 Scirocco cutting out. occasionally (with no pattern) the engine will cut out and die for no reason. Leave it for 2 minutes and it fires up again. When it happens as you are driving the engine lurches. If you put the clutch down you can still rev butas soon as you start to drive it is all over the place. Any ideas?

So far I have replaced:

Distributor cap
Fuel filter
All air hoses
Fuel filler
Had the tank professionally cleaned

This is really starting to irritate now so please help!!!
Scirocco woes... still - Malcolm_L
Leave it for 2 minutes.... I take it nothing happens if you
try to start it within 2 minutes?

If this is the case, have you checked you are getting a spark?

Why was the fuel filler replaced - did you suspect water was getting in to the fuel?

Also have you cleaned the carb - this sounds more like fuel starvation than ignition.

Scirocco woes... still - montag
Sometimes starts after a minute, sometimes not. The filler had a hole in it and the tank was filthy. Lots of electricity getting to the plugs if the shock I got was anything to go by. RAC had to come out last week and they blew the jets out.

Just tried it and the filter was dry so no fuel was getting through. Couldn't start it at all and blew the fuel pipe out and purred again so I think it must be a blocked fuel line.

New filter is already fairly gunky.

Have a new distributor as it may also be the hall chip.
Scirocco woes... still - Cambridge
This definitely sounds like fuel starvation.

I had same symptons in an old van years ago. Made it to Glastonbury though ...

I think you have to remove the tank. Then either flush it out, or replace it. But any second hand tank from a scarpyard may be worse than the one you've got.
You should also try to clean out all fuel lines etc.

Is the filler cap allowing air into the tank? If not, a vacuum is formed and fuel can't reach the engine.

Good luck.

Scirocco woes... still - pmh
The one thing missing on your list of replaced items is the fuel line and any flexible fuel pipes joining it to tank/pumps.

If it is a solid pipe I would try taking of all flexibles, disconnecting pump(s) and blow thro the solid pipe with compressed air and then replace the flexibles with new ones. Old pipes can go flat with suction and inhibit fuel flow or delaminate internally and create a blockage.

Does it have a mechanical fuel pump, if so why not try running with a temporary fuel feed from a separate tank in the car and all new fuel line. (But be careful with petrol!)

pmh (was peter)
Scirocco woes... still - pete&hisgolf
Had a similar problem with my Mark2 Golf a few months ago. Had the leads replaced but no joy. Mechanic and I were reluctant to go down expensive route of pulling apart the fuel system and he suggested it might be the new petrol gap I'd just had fitted (non standard VW cap) - thought it might be creating a vacuum in the tank preventing the fuel flowing out.

I've driven around with the cap only loosely fastened ever since and the problem hasn't recurred. I've also used more revs as I was getting into the habit of chuntering around on low revs and wondered if that was having an effect. Still wonder if it was the petrol cap or just some dirt that worked its way out of the system, but it might be worth a try. Good luck anyway.

Scirocco woes... still - montag
Hi all and thanks for your time.

The tank was completely removed and flushed. Took 3 attempted to completely clear and defume it.

Does seem like next attempt will be fuel lines.

I posted again about bubbles in return line. Is this normal on tickover? When it gets nice and warm the tickover drops and I get bubbles. Is this going to be all part of the same?
Scirocco woes... still - Drew20
I have a spare fuel tank if you want it!!!

burbling is probably fuel mixture settings on the carb


Value my car