I ran the car again today and it had the same issue on the same corner. I pulled the data and the FP was solid through the entire lap other than the single right turn with hard braking. I emptied the tank after it first happened today and it had 1.2 gallons in it. I added 5 gallons and ran again, it started to trip FP pressure again with about 2.3 gallons left.
At this point I think I might need to pull the fuel pump and check the bottom of the pump.
@fsts2k ... completely normal from my experience. Both my RSX and the newer XX suffer fuel pressure 'dips' (not the Trips you are suffering) when I reach about 7 litres (~1.5 gallons) left in the fuel cell. I assume you have a fuel cell and not an aluminium tank?
I've programmed some 'Status Variables' into my AiM SW4 (in the XX) and into the MXL2 (RSX) that monitor things like this during each session. The great thing about Status Variables are that they are captured in the data and can be seen/analysed after each session.
Things like this happen so quickly you normally don't see the alarm and so it can be hard to diagnose. I've set the Status Variables to be 'captured' at levels before a 'Trip' would normally happen... trying to catch problems early... before it's the ECU just shutting the car off.
Here are the Status Variables I've programmed in.
After each session it takes less than 1 minute to look over the data and see if any of them have been 'triggered' (even momentarily like an oil pressure dip or fuel pressure dip)
I set up a 'Channels Report' in Race Studio 3 to look at these... anything with a '0' in the cell means the Status Variable didn't occur... so you just need to look for any '1's (which Race Studio assigns the colour green which makes it easier - would be better if it were red maybe as these things aren't 'good' ... but at least you can see the colours easily)
In this example you can see that I had 'Low Oil Temp' on the out lap (Status Variable is set at <60C) and then 'Low Water Temp' (Status Variable is set at <70C)
So at a glance you can tell that there were literally no issues in this short sprint race (other than the normal water/oil temp management on the out lap)
By using this approach I found the fuel pressure 'dips' well before I ever had a fuel pressure trip.
I actually went and found that session... here it was...
So you can see that I had a 'Fuel Pressure Low' alarm captured for the last 5 laps of this Qualifying Session.... you can see in the upper part of the Channel Report that the fuel pressure got as low as 3.12 bar on lap 5.
When you look at where these occur on the Time-Distance chart - they were all at a similar location in the same corner (within 50m of the same place each lap.)
See below
On this page in the data I built an 'Alarm Indicator' that simply shows if any of the 'Status Variables' have been triggered (if they are then you go to the Channels Report and look to see exactly which one was set off)
You can see that all the alarms on those laps occurred in a small section of the track (see right hand side).... and if you look at the lower left of the above you can see that it was at the end of a very long fast left hand sweeper... all the fuel was running to the non-pump end of the tank.
Hope this helps.
Rod, this is great! Thank you!
I do believe I have the aluminum fuel tank and it is nice to hear you have the same behavior around 1.5 gallons.
I am going to setup these status variables as well. Perhaps I just need to run more fuel...
We dug into the car yesterday and found a few things although no “smoking gun”.
- I have a fuel cell, not an aluminum tank.
- There was half a gallon or a gallon in the cell when we dumped it out which the fuel pump could not evacuate.
- The foam was mostly in place but the fuel pump was not tightly strapped in and was loose. This could have caused some of the pickup issue. It is now strapped in well and located at bottom of fuel box.
- The fuel return line was sitting outside the fuel box, we placed it inside now so it fills the fuel box to help in low fuel conditions.
- The fuel filler flap was not opening to the fuel cell because foam was blocking it. We cut out a section of the foam to enable fuel to go in easier.
- Put in in a new fuel filter.
I have also unlocked the AIM wheel and am working to set alarms for low fuel. I did find the car has TPMS but it is not sending the values from the PDM to the wheel. More to investigate there.
