fuel issue

[acapro]

Hi guys

Can someone help me out. I have a 5.0ltr VK Calais. In the morning I go to start it and for some reason it will not deliver fuel into the manifold. If I tip a bit of fuel down the carby it start and runs until the poured fuel runs out, some times I have to tip fuel in 5-15 times to get fuel to flow. After the car is running the car starts first kick for the rest of the day, it seems to only happen over night. I took it to Auto-Carbs east Brisbane last week and spent (wasted) $550 for them to basicly steam clean the outside of the carby because they did nothing else fix the problem.

Thanks in advance

[acapro]

I will just add, It seems like overnight the fuel is running out of the fuel bowl and down the fuel line and that it is taking time cranking to get the fuel back up the line and into the bowl. Is this possible? also what are the two parts in front of the carby on the fuel line, one looks like a diaphragm the other looks like some sort of junction box, could they have anything to do with it?

Thanks again

[commy vk]

Go and get your money back

[DANNY8]

I'd check the pressure coming out of the fuel pump....or one morning just pull the hose off the carby and crank it over and see how much comes out. I rekon it's prolly the fuel pump which is stuffed.

[acapro]

Go and get your money back

working on that!

[acapro]

I'd check the pressure coming out of the fuel pump....or one morning just pull the hose off the carby and crank it over and see how much comes out. I rekon it's prolly the fuel pump which is stuffed.

if the fuel pump is stuff wouldn't it stay stuffed? Tomorrow I will pull the line off

[DANNY8]

The fuel might be draining back thru, and the pump might not be strong enuf to be able to supply fuel on first startup (as it has to pump it up again). You put fuel down the carby so it fires and runs, which means the fuel pump works more to get the fuel up (coz the motor goes quicker when it's running then cranking), and after a few shots I guess it has pumped fuel up to the carby and is ok until it sits for to long again.

Just a thought anyway, I'm not 100% sure. But for the 60 seconds it takes to remove the clamp off the fuel line and pull it off the barb, ya may as well give it a crack one morning to see if anything is coming out. Just don't automatically think it's the carb, work ur way backwards until u find the problem.

[machone]

id say it sounds like your fuel pump if its a mechanical fuel pump theres a diaphragm inside the pump that could be cracked and its not pumping fuel up to your carb....but when you manually put fuel in the carb it starts because its using vacuum to supply fuel somewhat like if you siphon petrol from your tank once you get it flowing gravity takes over...it also could be a sticky or obstructed needle valve.... firstly take the air cleaner off press down on the front butterflies and open them up now pump the primary throttle lever see if petrol is squirting out of the front jets.... no petrol then your float chamber is starved of petrol... also when cold that the top cover butterfly should be nearly closed when starting if its fully to half open that could also be your problem....the diaphragm i think your talking about is the fuel return....if no petrol from squirting the jets get a small jar and a spare fuel hose...undo the fuel line at the base of the carb...(theres a big nut there hold that with the right spanner or shifter if you havent got one... then with another spanner undo the smaller connection use the right spanner for that... the nut can round very easy) then use the spare fuel hose connect it to the fuel line so its between the fuel return and the carb have someone start the car whilst you put the fuel line in the jar if petrol is pumping at a steady rate then its your carb....while your there that big nut on the base of the carb undo it... inside there should be another fuel filter sometimes theres not but there should be... they can become blocked clean it while your there then reconnect the fuel line back up to the carb if your not getting a steady fuel rate when you undid the fuel line then undo the fuel line from the fuel pump that goes to the carb attach again the spare fuel line and put it into the jar...have someone start the car again if fuel isnt pumping then its your pump...if it is pumping then it could be that diaphragm your talking about on your fuel line or the carb has a sticky needle valve... also check your fuel filter thats its in working order....like danny im not 100 % sure but rockys i know a bit about them they can be temperamental but you can do a lot with them. hope that helps...and get your money back and pay me if it works lol... also take the car to a mechanic whos a carb specialist...hope that helped mate dont throw stones if it doesnt and dont blow yourself up either good luck.

[ari666]

does it have an intank pump and is your tachometric relay functioning?

VK have a small intank pump to assist delivery of fuel to the mechanical. but if your tachometric relay is not working, that pump wont push the fuel when you try and start it. then whats happening is the mechanical is trying to suck fuel though with an airlock.

first off, fix the leak. there has to be a leak somewhere. quaddys evaporate fuel, but not all the way down the line. your fuel lines should be sealed at the float, so itll just evaporate whats in the bowl.

[jcvhsle]

had the same problem with my sle. rebuilt the fuel pump but it has made no difference. if i dont start the car every week the fuel returns past the the fuel filter if the tank is really low. if i start the car every 2 days its fine. i cant explain why the fuel flows back past the pump when the internals are new, weird.

[commy vk]

I had a fuel problem a few years ago and thinking that I was doing the right thing I put a rebuild kit thru the fuel pump and thought it would solve my problem,but no it was still there.I ended up taking it to a good mechanic (old school) and he told me that I can rebuild the pump till the cows come home and he suggested getting a NEW pump.
Problem Solvered.

[ari666]

i think you will find that changing the float/needle/seat in the carby will have a better result...

just sayin'

[jcvhsle]

for my mind for the fuel to remain in the line past the pump and in the line leading to the carb a type of vaccum must be created. so if the fuel is flowing back then there must be a leak or pressure release in the system, does this make sense and if it does where does one begin