Possible fuel starvation issues with the GTS

[GT_II]

I suspect the horn is only supposed to work with the ignition on, as on modern VWs, but I will check the wiring diagram later. What model year is your GTS?

[GT_II]

Just checked the diagrams. The horn is fed from the same circuit as the fuel system electrics, so is disconnected when the ignition is switched off. For that reason, it is also one of the few electrical items that remains in circuit while the starter motor is engaged.

[Brenjacques]

Ah thanks for that, must be my mind playing tricks on me then! It's nice to have it back on the road, it did the trip to work fine today with no problems but I can't help but feel its starting to protest about it's use as a daily

[RussGLAuto]

This sounds a bit like bits of rust, crud, etc. in the tank. These gradually get sucked up round the filter on the end of the pick up after driving for a while, resulting in lack of power/throttle response. Stopping often allows this obstruction to drop back to the bottom of the tank, but to recur when next driving. The cause is corrosion/rust on the inside of the filler pipe and/or the fuel tank. If so the cure is either a new (stainless) filler pipe and/or new tank. This is possibly a bit of a long job for a weekend for a daily driver and needs time to get the necessary new bits, I did it for my Scala (now moved on), but I had another car as, together, these were needed as daily drivers.

Spot on!

[kidcrewbob]

As above - I had exactly the same 3 or 4 years ago - went down all the usual rabbit holes to find that only a new tank and filler neck fixed it......just crud getting sucked up at random intervals - scary! Has run like a dream ever since........coincidently it passed its MOT today actually at the first time of asking - 2 years running now !

[Brenjacques]

I think mine may have been something to do with the replacement swirl pot/vapour separator, I've done quite a few miles in it since with no problems now so it seems the fault is cured. I do want the get the weber looked at now though just because of this odd fuel pressure fault that I wrote about on another thread which is flooding the engine when it's off + it could do with a service and tuning just to see if it's all good. Are there still any good carb people based in the east mids? I used to use RPL here in Leicester but they've been closed up for a while now, shame really as they'd get carbs sorted and tuned spot on.

[RussGLAuto]

This sounds a bit like bits of rust, crud, etc. in the tank. These gradually get sucked up round the filter on the end of the pick up after driving for a while, resulting in lack of power/throttle response. Stopping often allows this obstruction to drop back to the bottom of the tank, but to recur when next driving. The cause is corrosion/rust on the inside of the filler pipe and/or the fuel tank. If so the cure is either a new (stainless) filler pipe and/or new tank. This is possibly a bit of a long job for a weekend for a daily driver and needs time to get the necessary new bits, I did it for my Scala (now moved on), but I had another car as, together, these were needed as daily drivers.

I'm with VI on this one, exactly what I had. You need to sort your fuel system out. Replacement filler neck, clean / new fuel tank and especially those hard fuel lines under the car, they are likely clogged with rust...

We keep on saying this for a reason. Clean fuel = happy carb. Simples

[Brenjacques]

Yeah I understand that they like to be spotless in the fuel system . It would be ideal to find out more history on the car, I don't think the tank or neck are original as the tank still has a legible paper sticker on it and no exterior rust, same with the filler neck, inside the tank is spotless, no debris sitting on the bottom. The only thing I did find were a couple of the small holes on the pick up were furred up a bit which I sorted. The hard lines are copper, unsure if that's the original material used from factory but they look suspiciously too clean for 37 year old lines, the only original rubber hoses left are the ones from the pick up to the solid lines. It hasn't missed a beat since refitting the original swirl pot and I've probably done a few hundred miles in it since along with a lot of rush hour traffic, traffic jams etc.

One other thing I need to sort is the vacuum/thermo switch in the air filter housing, the one that controls the warm air flap. It's a bit leaky which obviously won't help fuel/air mixture as the supply vaccum comes from the back of the carb/intake manifold. Anyone know if these are available anywhere?

[Brenjacques]

Well back to square one aren't we

Decided to take a short cut to work today involving a few speed bumps, immediately after going over one it spluttered and died, same problems again, can't rev past 2k and no power/stalling trying to pull away. Parked it up and walked to work whilst I await recovery and a likely parking ticket too!

Did have a very quick look and the flow in the filter looked very good at idle and whilst revving despite engine stalling and dying. Lots of fuel in there sloshing around and obviously being sucked though and sent down the return. Looking more likely that it's within the carb and something floating around in there blocking jets etc. Thinking about it, the car does have the common problem of oily air filter housing so could quite easily be crud being blown in from the gauze and working it's way into the carb. Might be wise to fit a catch tank instead.

Been absolutely fault free for the last couple of months but that's how these things go I suppose, hopefully this time I can get to the bottom of it.

[Brenjacques]

Hi everyone

Carb has been refurbed and will be back on the car soon. I've also decided to bite the bullet and get this fuel tank dropped down for sorting out. I'm erring more to just replacing it, more so 'cos daily and I'm sick of walking. It'll be quicker and easier to just swap than having to clean it all out and potentially miss something in there plus I can keep it around as a spare and clean at my own leisure. Also ordered a new filler neck from Tom at Dreadnought so that'll be changed too.

Seen these tanks on heritage, are they the correct type?

https://www.heritagepartscentre.com/uk/ ... gLirfD_BwE

My car is a 1985 with spacesaver so I presume this will be correct? Just want to check with the experts before parting with any money.

Still not sure what to do with the hard lines, I'm 99% sure they aren't original and the flow in the pick up line is great. I'm confident the problem is either going to be flakes in the tank or crud blowing up from the breather hose and blocking the jets.

[GT_II]

It sounds like you are leaving nothing to chance, so I hope it pays off. From VIN 53ZEZ022075 (part way through the 2004 model year), the bigger 55l tank was fitted, part number 155201075B. I don't know what the F suffix on the part number means (or the absence of a suffix on their non-branded version), but as Heritage says it is compatible, I doubt you would experience a problem making it fit.

[Brenjacques]

Yeah from what I can see it looks identical and I doubt there are many variations other than capacity. I know many have advised me well on this thread that I should sort the tank, it did look very clean though when I looked into the hole for the pick up but I guess it's only possible to see a very small section of the tank through there and all it takes is a few flakes finding their way towards the pick up to cause the problem.

It's got to a point now where I just want it sorting properly, the car regularly does long trips and I don't want it leaving me stranded somewhere dangerous or far from home. I think the final case of it happening after a few speed bumps is pretty conclusive that there's a blockage somewhere.

[RussGLAuto]

Do the hard fuel lines under the car - not too difficult. That's where all my rust was hiding...

[RussGLAuto]

https://www.classic-vw.co.uk/mk1-golf-c ... 7690-p.asp

[Brenjacques]

Ah nice one thanks for the link, I was looking for someone who stocked them. Parts have slowly been arriving and I now have a replacement tank if needed, filler neck and the carb has also been returned, due to be fitted. Wasn't happy with the new Febi carb flange I put on last time around as it's just a sort of hard rubber sealing ring on the bottom end and I wasn't very happy with it's sealing capabilities. I've managed to source a better full rubber moulded type which seems to have more sealing area and a softer, more compressable material.

Apparently the carb was full of crud and really needed a good clean inside, also pretty disappointed at the quality of some parts used from factory. The worst was the pump diaphragm which had hardened and was almost solid and warped, the carb is only three years old and really would have expected these sort of bits to last a couple more years at least.

Anyway with all of that said I'd better give the crankcase breather a sort out as most of the contamination has been from it flinging oil and dirt into the airbox. I know there's a method to burn the blocked gauze and get all of the ash out but I don't want to miss anything and block the carb up again so might see if I can find a new or old stock one. Also, I know the Mk2 golf's had a plastic oil spray tray/cover under the camshaft cover, can these be retrofitted onto the 8v carb engines? Might be a good idea to prevent any oil getting up to the gauze.