3.9 v8 temperature sender

Bloody hell.... Look how complex the vent system on the fuel tank is. For the first time ever I've found something useful in the manual I have here. You will love the suggested test for the tank vent system. Get this:

1. Ensure there is at least 2gallons of fuel in the tank
2. Disconnect at the adsorption canister the pipe the vapour seperator.
3. connect this pipe to nitrogen cylinder and water manometer using a "T" piece.
4. Pressurise the system to 27.5 inches of water .... and measure an pressure drop .........

Hey .... damn, there is a good suggestion there ... if a pressure drop is found, search for a nitrogen leak with soapy water at all the connections.

Now if I pump say 10psi into the tank from the charcoal canister under the bonnet I should be hear to hear where the leak is from the air hissing out right ?

seeya,
Shane L.

I've got a manometer you can borrow and I'll be in Ballarat today if that helps?

Leaving home around 11. If you get on here before then, PM me you address and phone number. :)

Quote:

---

Originally Posted by bacicat

I've got a manometer you can borrow and I'll be in Ballarat today if that helps?

Leaving home around 11. If you get on here before then, PM me you address and phone number. :)

---

Thanks for the offer! But Nah, I know there is a HUGE leak there, it wouldn't pressurise. I'm figuring if I put a few PSI in there I'll hear it hissing out from wherever the leak is. I might even be the safety pressure valve doesn't work ... so the air will just come straight back out :)

Say, what do you use a manometer for :confused: :)

seeya
Shane L.

Quote:

---

Originally Posted by DoubleChevron

Thanks for the offer! But Nah, I know there is a HUGE leak there, it wouldn't pressurise. I'm figuring if I put a few PSI in there I'll hear it hissing out from wherever the leak is. I might even be the safety pressure valve doesn't work ... so the air will just come straight back out :)

Say, what do you use a manometer for :confused: :)

seeya
Shane L.

---

[ame]http://youtu.be/9ytei6bu7kQ[/ame]

Oops, not quite. It is a device used for measuring pressure drop using a U shaped pipe with graduations on it - usually in inches of water. You connect one end to the test piece - gas pipe, ,fuel tank, etc and the other end stays open to atmosphere. You pressurise it to whatever - as your book said 27.5 Inches of water - so you increase the pressure in the test piece until the water goes up the tube 27.5" then turn everything off and wait to see if the water in the manometer forces any air out of the test piece. You can read his off the scale, so you might have a spec that says it can loose 2" water per hour - you can read this off the manometer after an hour.

Clear as mud? Maybe a Gas Plumber can explain it better, but I use mine to test fuel tanks, radiators, etc.

Quote:

---

Originally Posted by bacicat

Oops, not quite. It is a device used for measuring pressure drop using a U shaped pipe with graduations on it - usually in inches of water. You connect one end to the test piece - gas pipe, ,fuel tank, etc and the other end stays open to atmosphere. You pressurise it to whatever - as your book said 27.5 Inches of water - so you increase the pressure in the test piece until the water goes up the tube 27.5" then turn everything off and wait to see if the water in the manometer forces any air out of the test piece. You can read his off the scale, so you might have a spec that says it can loose 2" water per hour - you can read this off the manometer after an hour.

Clear as mud? Maybe a Gas Plumber can explain it better, but I use mine to test fuel tanks, radiators, etc.

---

Yes that makes sense. I'm thinking about just using a few psi from my air compressor into the vent system. They specify nitrogen as it's an inert gas.... But I don't have a regulator that would go anywhere near low enough to use nitrogen safely (infact I use a suicide line off the bottle when I use the nitrogen :o )

seeya,
Shane L.

Quote:

---

Originally Posted by DoubleChevron

Yes that makes sense. I'm thinking about just using a few psi from my air compressor into the vent system. They specify nitrogen as it's an inert gas.... But I don't have a regulator that would go anywhere near low enough to use nitrogen safely (infact I use a suicide line off the bottle when I use the nitrogen :o )

seeya,
Shane L.

---

I think that given the state of your system you'd be looking for flow rather than actual pressure, a disconnected hose won't hold anything...

Quote:

---

Originally Posted by bee utey

I think that given the state of your system you'd be looking for flow rather than actual pressure, a disconnected hose won't hold anything...

---

Yep, that's what I meant, I should be able to hear it hissing out somewhere :) At least I know where to start then when I dismantle it !

There is a known problem with 91 etc plastic tanks , in that they have 4 vents, one at each top corner and they can crack around the vents.
Secondly, AFAIR there is a non return valve up in the RH guard which can become detached.
It is normal for the tank to have pressure as it is only vented into the manifold under certain conditions, usually light throttle cruising.

You should also check the valve on top of the carbon canister to see if it opens.
Regards Philip A

The tank concerned is a steel auxiliary tank in the RH rear corner as the main plastic tank has been removed and replaced by 2 LPG cylinders. The filler pipe is all external, it lives outside of the inner skin of the RH rear area of the cargo bay. It isn't unusual for people to butcher the inner skin imagining that no fumes will enter through the holes. WRONG! I suggest you remove the loose items against the inner RH rear panel and the adjacent floor and seal all the holes before proceeding.