Scirocco Register

OK, just to add to this subject & then it can be closed for good & used for reference in the future.

For all those that have or are going to fit a Weber, then this is something worth noting. As the Weber requires a larger supply of fuel compaired to the Pieburg a restrictor MUST be fitted on the return to the tank line, otherwise airlocks start to happen when the engine is under load and all the fuel is pumped back to the tank instead of up to the carb. Don't ask me why as I would have thought that the pump would cope ok, but perhaps someone better at physics can explain that one.

Anyway, the cure, since I previously posted that I had used a brass hose connector from the old Pieburg, this said connector decided to pop out and into the end of the hose & therefore no longer restricted the fuel return & so the problem returned. Now, this is the clever bit, I had some heads from my Mig Welder sitting with the different size holes in them for the wire, so it turns out that the 0.8 size fits the retun pipe connector perfectly, you need to tap it first of all using an M6 thread, but this just takes 2 mins & it's guaranteed not to come out so long as it's screwed in nice & snuggly. Then the return hose pushed back on over the top. All very tidy & looks original too, anybody going to the Scottish meet the end of this month that has the same issue is more than welcome to one of the welder heads as I have some left & I can take my threading tools with me if they want it fitted, like I said, it's takes minutes & works perfectly.

Happy motoring!!

I might be being blind or a bit stupid,
But any more info on the Scotish meet?? Where/when etc.

Hey,

I'm kinda new to the scirocco scene, but i've recently had a similar problem with my car and I found out that it was down to the fact that the fuel tank was full of crud and it was clogging up the fuel filter. I would suggest replacing the fuel filter (£2) and seeing if you see any improvement.

Hope this helps,

Andy

I haven't heard anything more about the Scottish meet, am waiting with anticipation.

As to the fueling problems, I can confirm that there is no crud in the system, clean as can be & filter not showing anything in it other than the usual small amount expected through general running (it is about due another change) I change my fuel filter every 5k when I do the oil as a matter of routine.

The problem was definately the return line as the problem went away when it was clamped with my trusty mole grips to restric the flow, which was a constant high flow which it shouldn't be under normal running, at least not with a weber fitted, should only be a small amount being returned on liftoff from high throttle & turning the engine off to provide pressure relief from the carb supply (same as my old Fords). Now that I have threaded & fitted the restrictor the problem has not come back, which is something anybody suffering similar problems with a Weber fitted might want to check.

so all i need is. new pump and a restrictor in the fuel return? as i too are getting the same problems. car hates going up any hill or hates over taking just splutters and ends up limping up the rest of the hill. only does it when up to temp. SOOO ANOYING!!

So from what ive read i need to check. Fuel lines. The pump. The swirl pot. Fuel filter. Filler neck. Carb. Fuel return line. Ignition amp.


Grrr i was really starting to love my rocco now its turning into a head ache

If you have a weber you can replace the swirl pot with a y connector and use a 0.8mm welding tip for a restrictor, they screw into the plastic return hose perfectly.

I'd also be looking at the rubber carb base, they are prone to splitting.
If it's only after the engines warmed up it might also be worth looking for a small crack in the inlet manifold, unlikely if it's never been taken off, but possibly worth checking.

A magnet in the tank will help collect rust particles from the filler neck, and I also have a metal gauze type filter over the end of the pickup because the small holes inn the standard one easily get blocked if there's anything in the tank. I think its off a split screen van, will post a picture up later or tomorrow if I can.

Ben

I just got to the bottom of my long standing Weber carb issues with my latest Rocco where I thought I might have a carb leak at the base, fuel starvation or even a blowing exhaust.

I had done exactly what Ben had done with the y piece from Halfords with the welding tip as a restrictor. Still no improvement. I also changed the rubber base of the carb for a better quality Meyle part, still no improvement.

I then went back to the fuel pick up where I tried removing the fuel filter that I had modified and fitted going by a guide I had read to stop debris from the filler neck/tank. The filter was actually doing the restricting! Standard cap back on the end of the tube and all sorted.

Think a gauze would be more suitable and/ or a new filler neck if I can make time to fit it and rust proof the tank more. Then you are in to rear beam territory, another can of worms.

well my rocco has decided it doesent even want to bother going up a hill or run fine at all, it's sort of ok running cold, ive started it up and noticed the fuel filter is hardly filling up, i was driving home tonight and stopped due to the starvation issue 7 times before admitting defeat and getting towed home, litterally i drive it anywhere near a hill and it decided it wants to cut out and die, i even tryed taking it out of gear and coasting but the engine just stalled every time, the fuel filter doesent fill up at all there's literally less than 1/4 of fuel in the filter at any given time ive filled the tank up, ive poured redex in it, im gonna start hitting it soon.

I would check your fuel pick up by removing here (take fuel lines off first)..


You might well be faced with some debri(see arrows)that I had found in the holes of the pick up (there is a cap at the end of this that can come out but that would remove any first line of defence from debris)..


I fitted this customised filter but only just found it was restricting flow to the carb, possibly because it was clogged but it's away now..


Bear in mind as I am sure you have acknowledged you may have a very rusty filler neck,rusty tank, rusty fuel lines, even perished rubber pipes of the fuel system. You want good uninterrupted flow to the Weber with restriction back to the tank insuring the float bowls of the carb always have enough fuel. Routine changes of the standard fuel filter will be my aim in the short term.

The thing I realise is the smallest thing like a spec of dirt can cause havoc and can remain undetected. You've also got the fuel pump all fuel lines and the Carb itself with it's internals/ jets to consider. This thread is now loaded with info and links that should see most folk right with Weber carbs and aspects of Pierburgs I hope

Yeah cheers for the pikis. Im useless unless i can see a picture of what im looking for. Did you make that filter out of a inline filter thats next to the cambelt? Ive checked and double checked my filler neck and its fine. So after i finish work ill be looking in the tank for any rust/debris. Dont qite know how im going to clean the fuel lines (other than replacing them) ive orderd a metre of 8mm fuel hose so at least i can change all the rubber in the engine bay also orderd a new in line filter. Just got to find this weber cleaning/over haul kit.

Is it worth removing the swirl pot and give that a good clean too? Also is there any other quick temporay fixes for the fuel return line? Cant i just clamp it to restrict it or even block it so it doesent return at all?
I need to make a 20mile drive to my mates garage on wednesday to get it fully cleaned out.

Sorry for spelling mistakes and punctuation. Im on my phone at work tapping with my chunkey thumbs.

Yes It's basically a small inline filter that I cut the outer dome off but it seems to have been restricting things. I use a bigger filter at the cambelt end. If a car has been sitting say weeks, months or even years and then used any loose debris tend to find their way to the filters, jets and any small orifices. My pipes at the fuel tank end and my metal pipes look like they could do with replacing but I use my car every day so I reckon less likely for something to appear for now.

Here is a place to buy the service kit..
http://www.fastroadcars.co.uk/shop/inde ... oductId=91

See Club GTI for guides in their Carb section There is also a guide in the the current Practical Classics Magazine for similar carb.

You'll need to have some form of return or you'll run the risk of bursting a fuel line or fuel spraying out of a weak joint somewhere in the fuel system. The weber has a kind of tap connected to the floats so when the chambers are full it stops any more fuel coming in.

I think you'll struggle to clean the inside of the swirl pot as its a sealed unit, much easier to just swap it out for a Y connector, I got a pack of 2 for about £1.50 at halfords. And at the same time pick up a pack of welding tips for the restrictor. Think they were less than a fiver for 4 or 5 of them.

I used one of these over my in tank pickup...


Couldn't tell you where I got it from, I picked it up from one of the trade stands at a show. But I think it was labelled as for a split screen van.
I cut the end off the standard plastic "filter" slid this over and secured with a couple of cable ties.


Ben.

well it would seem my mechanical fuel pump is on its way out as its leaking from the first diphram. so heres the question do i convert to an eletric fuel pump at a cost of £30 or do i just get vwheritage tosend me over a repacement mechanical fuel pump? sure its easier to just bolt off and back on but to decide weather to improve the system is quite tempting.

well reading whats on offer at heritage. they have a electronic fuel pump kit that recomends use with the weber carb. so might aswell throw caution to the wind and go the eletronic fuel pump route.

Mechanical fuel pump is perfectly sufficient for your Weber carb.