LS7 Pollak Fuel Wiring
Discussion
Hi
I am new to this forum, so hello
look forward to seeing more on here.
Currently helping prepare a Ultima GTR, especially on the wiring side of things and could do with some help
I am a little cautious of the Ultimas Wiring loom and associated instructions when it comes to the pollak valve and the way they tap into the standard harness to control it. I would quite like some verification that I am in fact doing it correctly. The pollak valve is right behind the engine so verifying which wires go where is a bit lost and Pollaks wiring diagram is pretty useless.
The Valve had 3 wires coming out of it, black, purple and purple/white. I have connected the black to ground, purple to the interior light purple wire and the purple/white to the right hand fuel pump purple/white wire. On the switch side the only change I have made are to the left hand fuel pump to change that as per ultimas instructions for the surge pump.
Does this all sound correct to you? I was a little off put that the pollak would have 2 12V signals sent to it at one time for 1 of the states. At the moment the fuel gauge does not register either tank, but I suspect this is a dash issue, just want to check the theory for now
Thank you
Adam
I am new to this forum, so hello
look forward to seeing more on here.Currently helping prepare a Ultima GTR, especially on the wiring side of things and could do with some help

I am a little cautious of the Ultimas Wiring loom and associated instructions when it comes to the pollak valve and the way they tap into the standard harness to control it. I would quite like some verification that I am in fact doing it correctly. The pollak valve is right behind the engine so verifying which wires go where is a bit lost and Pollaks wiring diagram is pretty useless.
The Valve had 3 wires coming out of it, black, purple and purple/white. I have connected the black to ground, purple to the interior light purple wire and the purple/white to the right hand fuel pump purple/white wire. On the switch side the only change I have made are to the left hand fuel pump to change that as per ultimas instructions for the surge pump.
Does this all sound correct to you? I was a little off put that the pollak would have 2 12V signals sent to it at one time for 1 of the states. At the moment the fuel gauge does not register either tank, but I suspect this is a dash issue, just want to check the theory for now

Thank you
Adam
Sorry can't be of any help.
Having just removed the entire wiring loom with it's many modifications from my GTR I am not looking forward to trying to refit everything during the rebuild (even with lots of labeling).
I hope to simplify it somewhat so I can feel for you and understand your dilemma. I have next-to-no knowledge of automotive wiring.
Paul
Having just removed the entire wiring loom with it's many modifications from my GTR I am not looking forward to trying to refit everything during the rebuild (even with lots of labeling).
I hope to simplify it somewhat so I can feel for you and understand your dilemma. I have next-to-no knowledge of automotive wiring.
Paul
I have come into the build very late and making sense of it is a bit over whelming!
I can't believe Ultima don't even have a simple wiring diagram!! Just all those pages of connectors with no indication of what is what
Saying that, if anyone has a decent comprehensive wiring diagram of the standard loom that would help me out alot!
I can't believe Ultima don't even have a simple wiring diagram!! Just all those pages of connectors with no indication of what is what
Saying that, if anyone has a decent comprehensive wiring diagram of the standard loom that would help me out alot!
Are you wiring a 3 or 6 way Pollak? In what duty e.g. drawing from one tank and ensuring the fuel returns to same tank? The Pollak valve relies on reversing the polarity, normally achieved with a an 'on-on' double pole switch, but you may already have a switch for the fuel tanks you can draw from.
Julian
Julian
The valve is a 6 Port valve managing the flow and return to both tanks. There is a DPDT switch on the dash.
From what I can tell the ultima wiring has instructed me to wire the valve so it has a permanent negative and positive and one switched positive.
To me this doesn't sound right at all?
From what I can tell the ultima wiring has instructed me to wire the valve so it has a permanent negative and positive and one switched positive.
To me this doesn't sound right at all?
That valve was never fitted when we did that drawing, the car it was destined for had a -12 balance pipe between the tanks so never needed a silly pollak valve.
Ps the radiator switch in that drawing shows an earth on one side of the connections, it should be a +ve Green Ign 12v... I have the updated version if anyone needs it... But you will need MS Visio 2010.
Ps the radiator switch in that drawing shows an earth on one side of the connections, it should be a +ve Green Ign 12v... I have the updated version if anyone needs it... But you will need MS Visio 2010.
There should be a 6 way connector labeled A-F and IIRC std wiring is;
A - To Tank 1
B - To Tank 2
C - Fuel Gauge
D - Selector Switch (Tank 1)
E - Selector Switch (Tank 2)
F - Not used
If you don't want to trigger the respective tank pump to come on with the valve, the A/B may not be required, so it's a simple 3 wire, which it sounds like you are doing. Either way what you have sounds incorrect and both the +ve wires should likely go to the selector switch to trigger the shuttle left or right. I'd suggest bench wire it and confirm with a voltmeter and by blowing through the valve ports to see which are open.
I was going to use a Pollak in my GT40 FI install, just didn't like the barbed plastic fittings and decided to use two 3 way solenoid valves with threaded fittings to keep the fuel system fully braided and -AN fittings.
As Clive says a balance tube between tanks alleviates a lot of hassle and plumbing, my Ultima EFI is setup with a balance tube.
Julian
A - To Tank 1
B - To Tank 2
C - Fuel Gauge
D - Selector Switch (Tank 1)
E - Selector Switch (Tank 2)
F - Not used
If you don't want to trigger the respective tank pump to come on with the valve, the A/B may not be required, so it's a simple 3 wire, which it sounds like you are doing. Either way what you have sounds incorrect and both the +ve wires should likely go to the selector switch to trigger the shuttle left or right. I'd suggest bench wire it and confirm with a voltmeter and by blowing through the valve ports to see which are open.
I was going to use a Pollak in my GT40 FI install, just didn't like the barbed plastic fittings and decided to use two 3 way solenoid valves with threaded fittings to keep the fuel system fully braided and -AN fittings.
As Clive says a balance tube between tanks alleviates a lot of hassle and plumbing, my Ultima EFI is setup with a balance tube.
Julian
Edited by JoulesCanAm on Sunday 6th March 15:54
Thank you for your help with that, that is pretty much as I assumed it would work aswell.
So to get you right, D and E need to be switched positives, what about the earth? Or is it a case that it is D +ve E -ve for one tank and vice versa for the other tank? Seems like a re-wire is going to be necessary here.
Personally I would much prefer solenoid valves or a balance tube as I am much more familiar with these, especially for racing!
So to get you right, D and E need to be switched positives, what about the earth? Or is it a case that it is D +ve E -ve for one tank and vice versa for the other tank? Seems like a re-wire is going to be necessary here.
Personally I would much prefer solenoid valves or a balance tube as I am much more familiar with these, especially for racing!
One of the things that worries me regarding this setup is when either of the tanks runs out of fuel.
OK I know that the level sensors should give you some warning, but if you do run out, the LP pump (vane type) very quickly is knackered from running dry!
Well, it was in my case! I killed 2 factory ones (got very, very noisy - even with fuel refill), and now I have replaced with a gyrotor pump which I hope is more resilient...and I have not even been on the road yet!
Setting up the fuel level sensors is something that also is a concern. Anyone recommend how do we set this up to accurately reflect an empty and full tank with an SPA dash system? That is my next job!
OK I know that the level sensors should give you some warning, but if you do run out, the LP pump (vane type) very quickly is knackered from running dry!
Well, it was in my case! I killed 2 factory ones (got very, very noisy - even with fuel refill), and now I have replaced with a gyrotor pump which I hope is more resilient...and I have not even been on the road yet!
Setting up the fuel level sensors is something that also is a concern. Anyone recommend how do we set this up to accurately reflect an empty and full tank with an SPA dash system? That is my next job!
adam001 said:
So to get you right, D and E need to be switched positives, what about the earth? Or is it a case that it is D +ve E -ve for one tank and vice versa for the other tank? Seems like a re-wire is going to be necessary here.
Some time ago, but I thought that D&E reversed polarity.V8 Vum said:
One of the things that worries me regarding this setup is when either of the tanks runs out of fuel.
With a balance tube I have to maintain my tanks over 1/4 full for track or the G's in the corners will cause the pump to run dry.Julian
Does anyone really know what tolerance these pumps have to running dry?
From my experiences, it does seem a problem, and if indeed you can wreck a pump so quickly, one would have thought that there was a good way to avoid this (apart from not running out at all of course), maybe with some sort of failsafe cut out mechanism to protect the pump?
I have two vane types as said before, and although they do still work, they screech horribly. On opening the bottom, you can see some minor marks on the circular flat plate, but not much else.
From my experiences, it does seem a problem, and if indeed you can wreck a pump so quickly, one would have thought that there was a good way to avoid this (apart from not running out at all of course), maybe with some sort of failsafe cut out mechanism to protect the pump?
I have two vane types as said before, and although they do still work, they screech horribly. On opening the bottom, you can see some minor marks on the circular flat plate, but not much else.
Edited by V8 Vum on Thursday 10th March 11:34
You are correct in thinking D and E are reversed to switch the valve one way or the other.
Link to the wiring diagrams below.
http://www.biotuning.co.uk/images/Selector%20Valve...
Dave
Link to the wiring diagrams below.
http://www.biotuning.co.uk/images/Selector%20Valve...
Dave
Hey,
Did a bit more work today and it seems that the Ultima way of doing it with a permanent positive and Permanent Negative and one switched positive seems to work, I can hear the valve switching and at testing it has seemed to have used fuel from both tanks.
A link pipe will be next on the list though hopefully
Asdam
Did a bit more work today and it seems that the Ultima way of doing it with a permanent positive and Permanent Negative and one switched positive seems to work, I can hear the valve switching and at testing it has seemed to have used fuel from both tanks.
A link pipe will be next on the list though hopefully
Asdam
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