VS stops dead on half a tank of fuel! Please help!

[lifes_telephone]

I've had my 1996 VS Acclaim for a year now and nothing seemed wrong with it until about two months ago when it wouldn't start for me at a shopping centre. It worked fine for a few weeks until it suddenly stopped dead at random places. It continued for a week to stop and start until I took it to a mechanic who immediatly replaced the Fuel Pump and the Fuel Filter. It worked fine for a day until it stopped working. The car was rtaken back to them and they couldn't find what was wrong with it and told me to simply 'keep a half a tank of fuel or more in at all times to fix it'. It continued to stop and start for three weeks and then I thought it might be the Crank Angle Sensor. I had that replaced, and it still continued to do it.
Through a series of events that same day, I had to replace the Alternator and the Battery. Didn't fix problem.

Put $20 of fuel in and car worked fine, it continued to work fine the next day,until it stopped dead at a set of lights. This time it was worse, car was stopping every 100 metres or so.
A few days later, the car got that bad that it had to be physically pushed around the corner from my house because it wouldn't start. Put $15 of fuel in and car worked fine. I've put almost $100 of fuel in the car in the last week just to keep it above half way. Is anyone else having the same problem? Or any suggestions on how to fix the problem would be greatly appreciated.

Thanks, lifes_telephone.

 

[aussieguy50]

the easy way would be to drain the fuel tank seams like it may have water in there.or the tank sender is not working correctly. or methelated spirits will dispert the water but it would take a bit to get rid of half a tank

 

[Brett_jjj]

You would think that if the mechanics replaced the fuel pump they would have had to drain the tank to get the pump out.So it should not have water in it.If it has you should go and see them about it.They should have checked for things like that before replacing fuel pumps etc.Try doing an error check,heres the link to instructions on how to do this.---https://forums.justcommodores.com.au/threads/checking-error-codes-vr-vs-revised.22307---It sounds like the CAS (Crank Angle Sensor).The symptoms you describe are similar to what happens when the CAS stuffs up.What type of CAS did you fit.Ive seen brand new aftermarket CAS's cause trouble from new.We fitted the CAS,had the same problems still,then after hours of stuffing around and finding nothing obviously wrong we fitted a genuine holden CAS and the car has run perfectly ever since.If the CAS was not a genuine holden part,theres a small chance it might be faulty from new like the one we had.As mentioned in the above post try putting a cup of metho to your fuel tank(have the tank about half full).It wont hurt anything,the metho just lets any water or moisture in your tank mix with the fuel so it can get burned off in the combustion process.

 

[RX25SE]

Sounds like a fault with the swirl pot inside the tank. The mechanic may have yanked on the intank return line when the new pump was fitted. This may prevent the returning fuel from keeping the swirl pot (where the pump draws fuel) full. Over about half full the fuel just pours over the top of the pot (its like a small ice cream container) so the pump always has fuel to draw.
The only way to fix it is to replace the tank.

For a mechanic to tell you "just keep more than half a tank in it to fix it" is the biggest load of $hit. Damn slack. You have paid to have a problem fixed, and so it should be. Mechanics like that are the ones who give the trade a bad name. I would suggest where he could jam the fuel pump. *rants*

When I bought my VS wag the previous owner told me to never let it get below 1/4 full or it may cut out. As I was aware of what kills a VS, I immediatley replaced the crank sensor and fuel pump. Someone had already done the pump and I noticed the pickup/sender unit was a little bent, so I bent it back. Then I ended up with the problem you describe, cuts out at half tank. After re bending the sender a few times, I replaced the tank. Fixed.

 

[Brett_jjj]

The swirl pot shouldnt effect it when its half full.The pump doesnt pick up its fuel up from the swirl pot. The swirl pot is there to stop the fuel in the tank that the pump is picking up being aerated and swirled around by the fuel thats being returned to the tank..The returned fuel is released into the swirl pot.Theres some good pics somewhere on here of the swirl pot where someone cut their tank open,and fixed their return line.A good example is get a bucket or tub and put a hose into it along the side,then turn it on.The water will swirl around and go up the sides of the bucket,and leaves a "hole" in the middle.The same thing happens inside the fuel tank.The returning fuel acts like the hose and the fuel ends up swirling up the outsides of the tank and leaves a "hole" in the middle,right where the pump pickup is.So thats why they release it into the swirl pot,which prevents this from happening.

 

[moff_man]

http://forums.justcommodores.com.au...1997/122605-fuel-return-line-inside-tank.html

im having a simallar issue as well, but mine is happining at 1/4 tank and ive taken my sender out and i have no return hose.

i have since open my tank up as in the above link and added a hose, readjusted my sender unit to show empty when the tank is empy, and re welded. im am awaiting on a new tank anyways becaue i have found too much rust and such in side

 

[wortus]

The fuel pump and pickup sits inside the swirl pot and the purpose of the swirl pot is to provide a reservoir of fuel to prevent the fuel pick up becoming uncovered during cornering or when the fuel level in the tank is low.
The fuel return line is connected to a venturi at the base of the swirl pot. This high velocity jet of return fuel picks up extra fuel and delivers it to the pot through a tangential passage. This keeps the pot full of fuel irrespective of the level in the tank and the swirling action seperates air and vapour from the fuel.

Clearly if your car cuts out there is air in the fuel lines going to the engine because the swirl pot is no longer connected to the return line.

 

[Brett_jjj]

The swirl pot is not near the pump pickup.Look at where it is situated inside the tank.Theres pics posted on here,and its nowhere near the pickup.I checked it out when I renewed my fuel pump too.My return line ran from the pump assembly to the swirl pot which was near the rear of the tank(sort of) and to one side.The fuel pickup sits closer to the front and middle of the tank.

 

[wortus]

The swirl pot is not near the pump pickup.Look at where it is situated inside the tank.Theres pics posted on here,and its nowhere near the pickup.I checked it out when I renewed my fuel pump too.My return line ran from the pump assembly to the swirl pot which was near the rear of the tank(sort of) and to one side.The fuel pickup sits closer to the front and middle of the tank.

That was quoted directly from a factory VN service manual volume 6 and I can't see a VR/VS being any different Brett so respectfully I will believe that and you can believe what you think thanks all the same.

 

[RX25SE]

VS has the pump sitting inside the swirl pot.