997.1 Cup Low Fuel Pressure Question
08-06-2018, 11:02 AM
#1
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997.1 Cup Low Fuel Pressure Question
Low fuel pressure light went off with 21 gallons in the tank. Data shows a 1.8 second dip below 3.5 bar in high speed S turn (started in transition section), then 7 second dip starting in same S turn the following lap. Zero or partial throttle. The second longer duration pressure drop tripped the light and I ended the session after the next turn. Data shows 3.6 bar or more for last turn and entire trip to paddock. Data also shows 3.6 bar or more for entire previous 30 min session.
Start by replacing filters and pump or possible loose connection? Any thoughts?
Thanks in advance.
Edit: Between driving and instructing I apparently missed a fill up. Chalking this up to low fuel.
Start by replacing filters and pump or possible loose connection? Any thoughts?
Thanks in advance.
Edit: Between driving and instructing I apparently missed a fill up. Chalking this up to low fuel.
Last edited by Thales; 08-06-2018 at 03:14 PM.
08-07-2018, 12:16 AM
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21 is essentially a typo, sorry. Second weekend with the car, first time diving into the MoTeC data. My apologies. At the event I thought I had 6 and had 1.
Going forward, my plan is to add known quantities of fuel and subtract change in Fuel Used. Is there a better method outside of weighing the car?
Going forward, my plan is to add known quantities of fuel and subtract change in Fuel Used. Is there a better method outside of weighing the car?
08-07-2018, 02:07 AM
#5
In my case, when the car comes out of the trailer, I already know that I have at most 2 gallons in the tank - because the car was last driven on the final lap of a race at a previous event (assuming my fuel calculations were correct). I add 3 gallons and assume I have 5 at the start of the first session. Knowing how much fuel I use per lap at each track, I then just add the right amount of fuel after every session based on how many laps I did. The only time I pump out dry is before each qualy, at which time I add 2 or 3 gallons depending on the track. I then pump out right after to measure exactly how much fuel I use per lap. Then fill accordingly for the race up next. Knowing exactly how much I use per lap helps me to be pretty accurate on my fuel estimates for the practice sessions at any given track.
08-07-2018, 09:40 AM
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Had same issue at Mosport this weekend with a full tank (we pump out every time car comes off), ran the car on reserve pump. The pumps will eventually fail and should be replaced by newer models according to pro team mechanic at track.
08-07-2018, 09:47 AM
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In my case, when the car comes out of the trailer, I already know that I have at most 2 gallons in the tank - because the car was last driven on the final lap of a race at a previous event (assuming my fuel calculations were correct). I add 3 gallons and assume I have 5 at the start of the first session. Knowing how much fuel I use per lap at each track, I then just add the right amount of fuel after every session based on how many laps I did. The only time I pump out dry is before each qualy, at which time I add 2 or 3 gallons depending on the track. I then pump out right after to measure exactly how much fuel I use per lap. Then fill accordingly for the race up next. Knowing exactly how much I use per lap helps me to be pretty accurate on my fuel estimates for the practice sessions at any given track.
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08-07-2018, 09:50 AM
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Great to know. Any idea of the hours on your pumps that were replaced?
08-07-2018, 10:24 AM
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08-07-2018, 10:57 AM
#10
I had to have one of my pumps replaced this year. The pump hadn’t failed but was found out of spec during a pre race inspection.
The culpritt was a combination of leaving fuel in the tank and the original foam isn’t compatible with some of the additives in todays fuel and will decompose and clog the pick ups. In my case, they replaced the foam and pump with new and everything works as advertised.
The take away I got was if you have a 997 with the original foam in the tank, replace it with the new and improved version.
The car (and old fuel pump), had 120 hrs on the clock.
The culpritt was a combination of leaving fuel in the tank and the original foam isn’t compatible with some of the additives in todays fuel and will decompose and clog the pick ups. In my case, they replaced the foam and pump with new and everything works as advertised.
The take away I got was if you have a 997 with the original foam in the tank, replace it with the new and improved version.
The car (and old fuel pump), had 120 hrs on the clock.
08-07-2018, 11:13 AM
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I had to have one of my pumps replaced this year. The pump hadn’t failed but was found out of spec during a pre race inspection.
The culpritt was a combination of leaving fuel in the tank and the original foam isn’t compatible with some of the additives in todays fuel and will decompose and clog the pick ups. In my case, they replaced the foam and pump with new and everything works as advertised.
The take away I got was if you have a 997 with the original foam in the tank, replace it with the new and improved version.
The car (and old fuel pump), had 120 hrs on the clock.
The culpritt was a combination of leaving fuel in the tank and the original foam isn’t compatible with some of the additives in todays fuel and will decompose and clog the pick ups. In my case, they replaced the foam and pump with new and everything works as advertised.
The take away I got was if you have a 997 with the original foam in the tank, replace it with the new and improved version.
The car (and old fuel pump), had 120 hrs on the clock.
08-08-2018, 01:34 AM
#12
Kevin,
I don't know the volume, but I don't try for an extra lap when I hit the reserve (which is really rare as I'm pretty aware of the fuel I use and need).
Considering this talk of the reserve pump failing, going forward, I'll hit the reserve switch first and make sure I hear it when pumping out.
Mike
I don't know the volume, but I don't try for an extra lap when I hit the reserve (which is really rare as I'm pretty aware of the fuel I use and need).
Considering this talk of the reserve pump failing, going forward, I'll hit the reserve switch first and make sure I hear it when pumping out.
Mike