18 replies to this topic

[germini30]

Guys, I have fitted an in-line plastic fuel filter between the fuel pump and the carb. When the cars running the filter obviously fills so far with fuel, but, once its switched off the filter drains back. Car needs to be cranked a while then to get it to fire up. Should the fuel drain back? Hif44 carb fitted and mechanical fuel pump.

[phillrulz]

Guys, I have fitted an in-line plastic fuel filter between the fuel pump and the carb. When the cars running the filter obviously fills so far with fuel, but, once its switched off the filter drains back. Car needs to be cranked a while then to get it to fire up. Should the fuel drain back? Hif44 carb fitted and mechanical fuel pump.

 

Check your tank breather, could be blocked meaning its drawing a vacuum when running. When off the vacuum pulls the fuel back into the tank. 

 

Edit - easy test, take the fuel filler cap off run the car then turn it off see if it draws back into the tank

Edited by phillrulz, 03 June 2018 - 06:53 PM.

[Boycie]

Inside the fuel pump there is the main diaphragm and also one/ two(?) small valves that stop the fuel moving in the wrong direction.  I'd suggest that one of these are faulty/ stuck/ holed allowing the fuel to drain back through the lines.

[germini30]

New fuel pump

[germini30]

Just been out. Ran the car without the furl cap and the filter filled up straight away and not run back

[germini30]

Funny thing is though that the tank is vented anyways

[sledgehammer]

Funny thing is though that the tank is vented anyways

 the end of the vent pipe gets a bit soft & pulls it's self closed

 

it's a bit weird - but it happens

[germini30]

OK. What is the remedy for me. New cap or get some new fuel resistant hose for the vent. I been having some weird running issues so maybe the tank not venting hadn't helped

[phillrulz]

Just been out. Ran the car without the furl cap and the filter filled up straight away and not run back

 

 

Funny thing is though that the tank is vented anyways

 

 

Glad i could help ;) check the vent hose, as sledge said, at the top where it enters the tank it can fold over and close itself 

[germini30]

What kind of problems can this cause.

[phillrulz]

What kind of problems can this cause.

 

id say fix the existing hose. I also doubt the hose mini suppliers sell is rated petrol compatible probably just like 1/8" beer hose. But dont quote me on that. 

 

Have heard people say that if the vacuum is strong enough it can boil the petrol as its under reduced pressure. So i guess could cause bad engine running as your trying to inject / pump a known amount of petrol int the cylinder at a time.

 

 

But thats just my speculation. 

[germini30]

I see. I been getting an odd problem and also I was trying to adjust the mixture but the screw was hardly making any difference. Obviously because of a lack of fuel

[phillrulz]

I see. I been getting an odd problem and also I was trying to adjust the mixture but the screw was hardly making any difference. Obviously because of a lack of fuel

 

try tune it with the cap off or just wait till you change the hose. Just dont do like my friend and leave it off everytime he fills up the excess splashes into his boot and fills his battery box with petrol. Asking for trouble. 

[germini30]

I have bought some fuel pipe that I will fit. Hopefully it'll be problems solved

[germini30]

Damn it. Ran the car yesterday with the fuel cap off and the filter filled straight away. Filter stayed full and car drove great. However now the filter is nearly empty again and running the car without the fuel cap makes no difference. Blockage in the fuel tank maybe. I am getting a few bubbles now and again coming into the filter, and I am correct I. Thinking that the filter should be completely full and not only just a bit