Anti Slosh device with low fuel light damping built in

[jasonc00001]

Hello All,

Following on from my previous Anti Slosh post http://www.lotusexcel.net/phpbb/viewtop ... =27&t=5602

and a conversation with spiyda who supplied the original unit.

There is now a MK2 which stops the annoying wandering needle , but now also stops the flashing low fuel warning light.

My 86 Lotus Excel no longer mithers me with the flashing low fuel dash light and the gauge holds true on corners. I have to say at this point it transforms my car. I don't ever remember not noticing the annoying low fuel flashing dash light. I might even recognise an oil light if it shows up ....

Anyhows,

Bought the Fuel Gauge Anti-Slosh Device MK2 from spiyda
https://www.spiyda.com/magento/index.ph ... g-mk2.html

Fitted in the boot with a homemade loom , all plugs and sockets , no cutting the original loom here !




Power from the flow lock valve



Signal feeds from the tank sender unit



All sent to spiyda's unit



Nicely glued to the bodywork in the boot and off it goes.

Job done.

Note: My 86 excel is an early version without the inbuilt lotus fuel damping unit. Here's the relevant manual wiring diagram..





Jason C.

[DWH]

Well done Jason

I bought the anti-slosh unit a month ago and intend to fit it in the boot on my car also. Really good idea to make it totally removable.

Where did you pick up your live feed from ?

Thanks

[jasonc00001]

Live feed from the flow lock valve white connector (2 pin).

Stuck a 2 amp fuse in the jump off point live feed to spyda's unit just in case.

Hope the helps !

Jason C.

[steven popay]

I have just fitted this device and it is great, no more ticking from the fuel gauge going mad.
just a couple of problems, I connected the live to the flow lock valve but it is getting interferance from the fuel pump resultin in a pulse on the needle, but when i investigated the pump there is no suppressor on it so im hoping thats an easy fix. The other problem is that it is reading 1/8 of a tank more than without it, is this just reading more accurately with the device so when it reads empty it really is empty?.
Also when i switch the ignition on the gauge reads 1/4 of a tank too much but within a few seconds settles back down, is this normal?
thanks steve.

[jasonc00001]

Morning,

In reply to Steve's comments below :-

I have just fitted this device and it is great, no more ticking from the fuel gauge going mad.
It is a wonderful thing. Went to wolverhampton in mine last week , and didn't flicker once..

just a couple of problems, I connected the live to the flow lock valve but it is getting interferance from the fuel pump resultin in a pulse on the needle,
Yep mine does that, but it settles when the pump catches up and the alternator is running at capacity.
but when i investigated the pump there is no suppressor on it so im hoping thats an easy fix.
Not noticed on mine. But I don't mind a bit of a needle twitch if it stops the light and wander.
The other problem is that it is reading 1/8 of a tank more than without it, is this just reading more accurately with the device so when it reads empty it really is empty?.
Again yep, mine was slightly off. Shows slightly more full than without it, but I did run it off the gauge (with a full spare petrol can in boot just in case) with the light on. Plus I always fill it up when the light eventually comes on.
I don't recommend this though , as previously I ran out of fuel and sucked all the rubbish out of the tank into the carb filters. Someone had put a screwdriver through the tank filter ??? Causing me to follow the re-plumb of the fuel lines to include a large inline fuel filter.
Also when i switch the ignition on the gauge reads 1/4 of a tank too much but within a few seconds settles back down, is this normal?
thanks steve.
Yep the device on mine goes from 3/4 full to the level on initial startup. Slowing down as it gets closer to the level in the tank.


Hope that helps !

Jason C.

[spiyda]

Morning,

In reply to Steve's comments below :-

I have just fitted this device and it is great, no more ticking from the fuel gauge going mad.
It is a wonderful thing. Went to wolverhampton in mine last week , and didn't flicker once..

just a couple of problems, I connected the live to the flow lock valve but it is getting interferance from the fuel pump resultin in a pulse on the needle,
Yep mine does that, but it settles when the pump catches up and the alternator is running at capacity.
but when i investigated the pump there is no suppressor on it so im hoping thats an easy fix.
Not noticed on mine. But I don't mind a bit of a needle twitch if it stops the light and wander.
The other problem is that it is reading 1/8 of a tank more than without it, is this just reading more accurately with the device so when it reads empty it really is empty?.
Again yep, mine was slightly off. Shows slightly more full than without it, but I did run it off the gauge (with a full spare petrol can in boot just in case) with the light on. Plus I always fill it up when the light eventually comes on.
I don't recommend this though , as previously I ran out of fuel and sucked all the rubbish out of the tank into the carb filters. Someone had put a screwdriver through the tank filter ??? Causing me to follow the re-plumb of the fuel lines to include a large inline fuel filter.
Also when i switch the ignition on the gauge reads 1/4 of a tank too much but within a few seconds settles back down, is this normal?
thanks steve.
Yep the device on mine goes from 3/4 full to the level on initial startup. Slowing down as it gets closer to the level in the tank.


Hope that helps !

Jason C.

Hi Folks..

I hope the new version is an improvement on the old version..
I didn't know that it read slightly high until I read this,
The circuit was built specifically for the Lotus VDO gauge so I'm not 100% sure why it woul differ from the OEM setup.
Maybe the second hand gauge I used to calibrate it was a bit tired ?
If it is a problem, I could tweak the circuit a little ?

The rise when switched on then the gentle fall to the correct reading is deliberate, modern instruments often work this way..
Its not foolproof, but it does give a better indication that the unit is working.

Chris (-=Spiyda=-)

[Lotus-e-Clan]

Hi Folks..

I hope the new version is an improvement on the old version..
I didn't know that it read slightly high until I read this,
The circuit was built specifically for the Lotus VDO gauge so I'm not 100% sure why it woul differ from the OEM setup.
Maybe the second hand gauge I used to calibrate it was a bit tired ?
If it is a problem, I could tweak the circuit a little ?

The rise when switched on then the gentle fall to the correct reading is deliberate, modern instruments often work this way..
Its not foolproof, but it does give a better indication that the unit is working.

Chris (-=Spiyda=-)

Could you not build-in a potentiometer for the owner to fine calibrate against a known volume of fuel in the tank (eg half a tank).

Mind you the mod won't be any good for me 'cos I ordered one from you yesterday. (unless you can do an upgrade kit to self solder for us techie types?

[steven popay]

Thank you for your replies, this is a great fix
steve.

[Lotus-e-Clan]

I'm fitting the anti-slosh2 module in the boot/tank area today.

Question regarding the Low fuel warning light feature (not 100% clear from instructions supplied).

• Am I right in assuming that you effectively disconnect the warning light /delay module wire from the OEM tank unit (so it's excluded) and connect this green/orange wire to the single low fuel warning light terminal of the anti-slosh2 unit?
  
  If I've understood it correctly, this would mean the low fuel warning light delay module (89SE) /warning light is now only receiving a signal determined by the anti-slosh2 unit ---- and this would confirm that the anti-slosh2 warning light terminal is a "sink to earth" just like the original warning light switch at the tank.

[Lotus-e-Clan]

I'm fitting the anti-slosh2 module in the boot/tank area today.

Question regarding the Low fuel warning light feature (not 100% clear from instructions supplied).

• Am I right in assuming that you effectively disconnect the warning light /delay module wire from the OEM tank unit (so it's excluded) and connect this green/orange wire to the single low fuel warning light terminal of the anti-slosh2 unit?
  
  If I've understood it correctly, this would mean the low fuel warning light delay module (89SE) /warning light is now only receiving a signal determined by the anti-slosh2 unit ---- and this would confirm that the anti-slosh2 warning light terminal is a "sink to earth" just like the original warning light switch at the tank.

Couldn't wait for a reply so I've finished the job and just got back from a road test.

Yes the fuel pump tick is pretty annoying and the capacitor doesn't stop the voltage spike which is a voltage drop in the pump feed line I think. Maybe an old school voltage stabiliser (not the 10v version) would cure that ...but then they tend to wobble too IIRC?

And yes, my gauge also reads near 1/8 higher with the AS2 module than without.

Don't know if the low fuel warning light bit works yet cos it shows between 1/4 and 2/4 tank (that'll be exactly 1/4 tank pre-AS2 module). Have to carry a spare galleon of v power until I know were we are at empty ...

Good not having the flashing fuel light on corners though. Just hope it comes on when it's supposed to ...

EDIT: N.B the later AS2 terminal block is too small for 5 AMP wire (esp if soldered), so stick to thin low amp wiring or, like me, you'll waste 1-2 hours wondering why the wires don't fit and stay in the terminal blocks!

[jasonc00001]

Hello Lotus-e-clan,

as below.

I'm fitting the anti-slosh2 module in the boot/tank area today.

Question regarding the Low fuel warning light feature (not 100% clear from instructions supplied).

Am I right in assuming that you effectively disconnect the warning light /delay module wire from the OEM tank unit (so it's excluded) and connect this green/orange wire to the single low fuel warning light terminal of the anti-slosh2 unit?
Yep, the Anti slosh unit provides the earth for you when it deems the level is low enough. This does replace the level switch in the tank, which is no longer used or connected.

If I've understood it correctly, this would mean the low fuel warning light delay module (89SE) /warning light is now only receiving a signal determined by the anti-slosh2 unit ---- and this would confirm that the anti-slosh2 warning light terminal is a "sink to earth" just like the original warning light switch at the tank.
Again, yes , it electronically sinks to earth, don't have a posh 98 with the low fuel warning light (or user manual to ref at mo) , but it should work as it effectively earths at a predetermined low level.


Also I commented to spiyda about the size of the connectors on the unit and had to tweak accordingly myself !!

But it is an ace device and stops the flashing 'G' / fuel light.

And the pump pulse is annoying but in mine 'stabilises' with a warm engine and alternator running at 12 to 14v.

Regards,

Jason C.

[Lotus-e-Clan]

A quick and dirty fix for the interference from the 12v feed from the fuel pump:

A Relay:

Fuel pump feed energises the relay and provides a clean 12v from the battery to the AS2.



If you use a 2A fused relay then that solves that problem too.


Simples.

EDIT: See next few posts- relay trick doesn't work. The quality of Earth to the unit is more important!

[Lotus-e-Clan]

B*LL*CKS not so simples dumbo!

Relaying the fuel pump 12v feed to get a clean battery 12v source does NOT stop the ticking needle!

I had also taken the earth off the harness that feeds the pump so maybe that's the issue.

SO! Next I'm going to provide a clean earth direct from battery and I'll get back!

[Lotus-e-Clan]

IT'S THE EARTH that's the problem folks!

Left the relayed clean battery source on the 12v side and took an earth direct off the battery to the AS2 and NO NEEDLE TICK!

SO then I removed the relay from the 12v side and reconnected the AS2 to the (dirty) 12v fuel pump source leaving the new direct to battery earth and STILL NO TICK!

This is making sense. The AS2 is sinking to earth via the fuel tank sender and mimicking the low fuel light switch by sinking to earth too, so no wonder earths are as, or more, important than the source. Plus I guess there is a 5v voltage conversion in the AS2 for the positive side which will buffer the dirty pump 12v source?

Anyway the cure is to take a clean earth from the battery to the AS2 unit to stop the ticking needle.

Now I'm happy!

Because many owners will install the AS2 in the boot area it would be a good idea to make clear in the instructions that the AS2 particularly needs a clean earth.

[Lotus-e-Clan]

Back from a "tick-free" ride out and got the fuel light to come on.

Well, the light comes on and goes off again and, whilst it's not the old wild flashing on & off with every bend, it's still reacting to "slosh" and I think maybe a trick has been missed with the latest AS2.

Perhaps the low fuel warning light output circuit should have been latched so it stays on after counting say 2 or 3 "on" signals within a time limit?

Maybe something to consider for the AS3?