Fuel supply issue '91 Cabrio carb

So the car was last on the road in 2008, and I’ve been restoring it.

here’s the story-

went for a road test and run out of fuel. Added 5 litres and she fired straight up and drove fine for another quick 2 mile blast.

Next day entered for MOT test, warmed her up, drove to the tester, added £20 of unleaded, she sat on the mot ramp ticking over sweetly for 10 mins and then just stopped, would not restart - in the in-line filter you could see fuel not moving during crank.

Aborted the test, recovered car.

Next day I disconnected the fuel line from the in-line filter and held my thumb over the end of the pipe while a mate cranked - I could feel suction but not very strong. (I suspected a fuel pump issue) how much sucking power should there be?

replaced the pipe and she started fine and ticks over sweetly again, but trapped in the in-line filter I can see tiny bits of what looks like rust particles, plus, a continuous flow of air bubbles.

ive checked and tightened all the fuel line connections RE the air bubbles but still getting them. What to do next? Any ideas?

It looks like it has two pipes from the sender in the top of the tank, running down under the car and connecting to metal fuel lines running to the engine bay and, then back to rubber fuel hose in/out of the carb, via the pump and vapour trap of course.

I am wondering where these air bubbles are coming from, and whether the lift pump is tired, and if the tank is rusty inside.

I will be removing the sender next week to take a peek inside the tank…

 

On my 1.8 carb Cabriolet the filter (inline under bonnet) is never full of petrol, always has air/fuel vapor in it.

To test the pump remove the outlet (onway to carb) and hold a rag over it whilst someone cranks, you should get a good health spurt, matron.

Def check the fuel filler pipe and inside the tank. I'd think 95% of fuel related problems with MK1s are down to water/rust/debris getting inside and blocking filters/pipes/jets/injectors and ruining everything inbetween.

Thanks…

Yes the in-line filter is half full with fuel, but it has round air bubbles pinging about inside of it, looks like they are coming from the supply end - I don't think it was doing that before….

If it had been stood for 12 years with a nearly empty tank there could have been condensation in the tank and it's started to rust internally. A subtle variation of rust from rotten filler neck.

If you can blow back down inlet fuel line at the fuel filter into the fuel tank, you should be able to hear bubbles in the tank when you blow, it is possible to blow with just your mouth so no worries if you don't have a compressor.

It could be when you ran out it's sucked dirt into the pipes.
There is no lift pump or anything in the fuel tank other than a fuel pick up (which may have some sort of filter on the end), a fuel return line and a float for the gauge.

Cheers guys, I'll give it a go, I don't fancy removing the pipes and sender in case I break something, but I guess it's got to be done. Have a little look in there and give it a blow.

Had a look inside the tank today, there’s lots of rust particles in the bottom of the tank, I scraped some away and the bottom line of the tank is clean

I can only see what’s directly below the hole for the sender though.

What to do?

Remove tank and flush it out , or replace the tank with a new one.?

There’s no filter on the end of the pickup pipe either.


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