vs v8 fuel problem?

[mUzZa88]

hi, i recently just put on a standard 73lt? fuel tank the problem is i didnt clean the tank which i should of, so the tank had very little fuel in it and had been sitting around for 6 months atleast lol, when i put it on i managed to syphon around 5 litres from my old tank to get me to the servo i chucked 20 bucks in an went for a thrash around, the car started surging bad so i took the fuel pump relay out an tried cranking it over, this worked for half an hour an stopped the surging but it came back after half hour how ever i since changed the fuel filter it was fkd, an put some injector cleaner in it, that has stopped the surging, the only problem i have now is it takes close to 10 seconds to start hot or cold an has a fair idle then its all ok, if i turn it off then back on it fires up straight away but after 5 minutes if i do that it goes back to taking 10 seconds to start etc could this possibly be a fuel pressure problem? the tank i put in was outta a vp calais v8 it had 2 small connections and one big connection on the top, my vs tank was 63lt and only had one big an one small connection so i blocked 1 of the small connections on this tank would that be playing a part in this ? i also put the fuel pump/sender out of my vs tank into the vp tank i have in the car , i been told it has air in the line or air leak or something so the pump doesnt have pressure straight away hence the 10 seconds to start? any help would be goood thanks

[moff_man]

ok to start with the housings are diffrent so the vs pump and gauge bracket will not fit in the tank propley.

the pump sounds like it stuffed due to the exsessive crap thats gorn through it.

i am not sure what you are talking about connections on top? do you have pic's?

the pump will need to be fitted to the tanks orignal sender unit/bracket

[mUzZa88]

hey mate, the pump an sender in either tank look exactly the same but im gonna change the pump tho like u said its more then likely stuffed from all the shit in the tank, and the connections i mean were the breather connects i can get a pic of my old tank not sure i might have a pic of the one thats fitted to the car now ill have a look.

[Brett_jjj]

The VN and early VP fuel tanks had the fuel return line seperate from the fuel pump assembly. The return line enters the tank through a seperate hose connector on the front of the tank ,not through the pump assembly like on newer models.I think this was changed during the late VP models..

[wortus]

With the breather hose connections the small connectors on the top of the tank are connected to pipes inside the tank and I am not sure if they are both the same so you may need to have a look and compare the inside of both tanks to see which one you need to use and which one to block off. On a VN/VP all 3 breathers go back to the filler neck and I'd probably be looking at fitting the filler neck out of one of those and connect it all up as per the VN/VP. This is only going to be an issue if your tank is not breathing and air is not getting in as fast as the fuel is used and causing a partial vacuum.
Did the VN/VP tank come out of a car with 2 fuel pumps? As far as I know the long range tanks onthe VN's and VP's came with 2 fuel pumps the internal is just a priming pump and is a bit shorter in length than the high pressure internal pumps and there is an external pump on a bracket just in front of the tank. Is the internal fule pump that came with the larger tank exactly the same as the one out of your car? The larger tank hangs down lower so are you sure the pickups are exactly the same?