Fuel overheating issues solved

[Storer]

As many of you will know I had a rather unfortunate arrival at the Great British Welcome at St Saturnin, Le Mans a couple of years ago when I had to be pushed into the show. Spending an hour in the traffic at 35 deg outside, the fuel got to 66 deg, it coughed and cut out. It was obvious why. After a couple of hours wandering around the show she had cooled down and fired straight up.

I have tried various ways of trying to solve the problem. None successful, until today.



I know I am not the first to try this but I have tried pretty much everything else so I know what doesn't work.

A quick test run has seen the fuel temperature start at 11 degrees and never moved from that temperature. It would normally be 20+ after a short run. My driveway is 600m long and stones so I go down it at tickover in first which sees the cooling fans kick in by the time I park up. Still 11 deg fuel temperature.

My fuel pump is an Aeromotive A1000 so moves a lot of fuel unless one of these is fitted.

Worth thinking about if you are starting from scratch or having hot fuel issues.


Paul

[Storer]

Ok, a few answers.

Graham is correct, my Aeromotive pressure regulator looks like a Christmas tree with both a pressure and temperature regulator on it. Fuel temperature is displayed on my SPA dash

I have obviously retained the regulator (at least for now) and it is set at 59psi. I have not changed any of the factory settings on the Fuel-on-demand (FOD) controller so it is set to a maximum of 75psi (which the regulator then dumps 6psi). I am running the FOD as a closed system as if I do decide to remove the regulator I will make a manifold for all the sensors.

I will look to adjust things when I get a bit of time. I suppose I was being a little cautious and changing the least amount in case it didn't work.

It was Mark's experience that gave me the confidence to spend over £300 on it.

I think using this type of controller and maybe their in tank pump in a new build would remove fuel temperature/evaporation as an issue completely.

If the fuel entering the rail is cool then heat soak should never be an issue.


Paul

[Storer]

MarkWebb said:

How long have I been going on about this! At last you guys are catching on!

We are all old gits, so bound to be slow to take things up!


Paul

[Storer]

deadscoob said:

I'd be really interested in seeing a list of everyone who has had the issue and the setup, exhaust, number of pumps, pump manufacturer etc etc.

I've not had the problem, was at Rockingham last August when t was about 30 degrees all day, car was going round all day, then drove home without a murmur.

Does everyone affected use aero motive pumps for instance?

If you are belting round a track or travelling at main road speeds there is/was no issue. Sitting in traffic for an hour is when the problem arises.
It is the fact that the fuel is being pumped through the pressure regulator (both the pumping and the regulation add heat to the fuel) and not then being utilised by the engine, but going back for 'another go round' is the issue. The bigger the pump capacity, the bigger the issue.

Paul

[Storer]

BogBeast said:

I would submit that if you suspect you have a fuel temp issue its probably best to measure it first.

To that end I would ask:

How hot is too hot?
Where should you measure it?
What should you measure it with?

I agree you need to know if you have a problem.

You will see in my post above that I have a temperature probe fitted to the regulator and at 60 degrees you have got a problem!


Paul

[Storer]

MarkWebb said:

Another option is to try running the FOD in returnless mode where no fuel is returned to the swirl pot at all.

Which is how I am running mine.

I also have a restrictor on the tank return from the swirl pot to give positive pressure for the HP pump which is only 4 inches from the pot.


Paul

[Storer]

Seems to work well but I still need to 'tune' the software.

No hot fuel issues since fitment.


Paul

[Storer]

F.C. said:

Storer said:

Seems to work well but I still need to 'tune' the software.

No hot fuel issues since fitment.


Paul

interestingly My tuner says I'm asking for trouble using FOD returnless with my boosted application he reckons it won't keep up with sudden changes and I run the risk of leaning out.
Ironically he said it would better work (for me) with a return.

You can use it with a return if necessary. My system was already returnless so wanted to try that first.

If you switch from FOD you are effectively switching the system off.
I suspect if you are planning a track day you would tweak the settings for a higher pump output.
The system is quite tuneable so you can set it up how you want it from your laptop while running if you wish.


Paul

[Storer]

It could be there is little demand.

Let's face it, you would not design a fuel system like the Ultima's if you were starting now.

Fuel would be in one central tank with built in sump/pot. One hp pump controlled by the ECU and single fine filter. One tank outlet to engine and one return from the rail.
Plus better aero and engine cooling from the side vents.



Paul