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Re: What is this???

Posted: Mon May 30, 2022 8:44 am
by Charlescrown
Getting the hose onto the barb wasn't a big issue. I bought a pair of long nose pliers 280mm and used 5/16 hose and it pushed over the barb fine. I agree with Vlad you can't get the fitting out of the swirl pot. I couldn't get a clamp onto the swirl pot fitting but considering it should only have a low pressure hope it won't come off. Time will tell.

Re: What is this???

Posted: Mon May 30, 2022 12:10 pm
by vlad01
There is quite a bit of pressure in them, especially at idle as the jet orifice in the venturi is only slightly more than 1mm.

Re: What is this???

Posted: Mon May 30, 2022 3:32 pm
by Charlescrown
Thought it might be a bit larger than that. I have measured the return line pressure on other cars and got between 30-70kpa. As I said time will tell.

Re: What is this???

Posted: Mon May 30, 2022 4:16 pm
by vlad01
I suppose it depends on the size of the pump. I know it's an issue on them as the inlet side of the return hose (fitting on the outside of the tank or sender for newer models) are just straight pipe section with no barb or just pushed on for the later sender style ones. I have seen this line blow off multiple times.


I am hoping the rumor that rares are developing commodore tanks is true and that the internal hose arrangement is much improved.

At prob 700-800 bucks, it will be a bargain compared to the recent VS nos tank I saw go for $2400 and $3500 for the VB tank.

Re: What is this???

Posted: Mon May 30, 2022 5:12 pm
by Charlescrown
Yea I did see where they are working on it. Considering the small size of the hole in the swirl pot fitting and it's gotta flow at least 2L a minute back to the tank it may well have quiet a bit of pressure. I might put the gauge on and measure the flow and pressure in the return line on Wednesday. Shit weather here again with wind and rain. It just started to dry out. I got called out to a VL a workshop had given up on and cheched the pressure on the return line after a bit of diagnosis and it was sky high. The ower didn't want to spend any more money on it so I pushed a rod hard into the return hose fitting which pushes the return line off inside the tank then filled it up with petrol and he sold it.

Re: What is this???

Posted: Mon May 30, 2022 6:13 pm
by Pete30nz
Its only a matter of time before i get the urge to pull my fuel pump out, because this long cranking is enoying. That being the ruturn line swirl pot hose is the culprit.

Re: What is this???

Posted: Mon May 30, 2022 6:15 pm
by vlad01
Pete30nz wrote:Its only a matter of time before i get the urge to pull my fuel pump out, because this long cranking is enoying. That being the ruturn line swirl pot hose is the culprit.

Either leaking injectors or bad check valve in the pump.

Bad return line only causes the engine to cut out mid right turn when the tank is below 1/3 to 1/2.

Re: What is this???

Posted: Mon May 30, 2022 6:18 pm
by vlad01
Charlescrown wrote:Yea I did see where they are working on it. Considering the small size of the hole in the swirl pot fitting and it's gotta flow at least 2L a minute back to the tank it may well have quiet a bit of pressure. I might put the gauge on and measure the flow and pressure in the return line on Wednesday. Shit weather here again with wind and rain. It just started to dry out. I got called out to a VL a workshop had given up on and cheched the pressure on the return line after a bit of diagnosis and it was sky high. The ower didn't want to spend any more money on it so I pushed a rod hard into the return hose fitting which pushes the return line off inside the tank then filled it up with petrol and he sold it.
I was just told they are making them to original spec and opting for a nitrile rubber hose :thumbdown: But there was mention of viton which would be a lot better.

Re: What is this???

Posted: Mon May 30, 2022 7:43 pm
by Pete30nz
vlad01 wrote:
Pete30nz wrote:Its only a matter of time before i get the urge to pull my fuel pump out, because this long cranking is enoying. That being the ruturn line swirl pot hose is the culprit.

Either leaking injectors or bad check valve in the pump.

Bad return line only causes the engine to cut out mid right turn when the tank is below 1/3 to 1/2.
I fitted a check valve in the fuel line beside the tank recently. But that still hasnt made it much better. :? Its one of those aluminium check valves with the hex's.

Re: What is this???

Posted: Mon May 30, 2022 9:46 pm
by vlad01
Maybe check for leaking injectors? Run the car for 30min and then lift the fuel rails with the injectors, prime the pump on and watch the ends of the injectors for weeping fuel or dripping. Very common issue with the age of the cars, especially true for the older VN-VR big body injectors, they really sucked for this problem. Also happens when you get the injectors serviced, they start leaking.

The leaking floods the engine and makes it take ages to start. Also check the vac reference hose for the fuel reg. Just yesterday I found that to be the problem in my nephews new engine and why it was flooding and hydrolocking. Fuel was pissing out of the vac line and into the manifold.