Odd Gremlin with Fuel Light ON - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

sw20kosh · 08-30-2013, 03:32 PM

This is a weird question that maybe someone here who has modified their ecu + fuel system has a simple answer to.

Twice now I have lost throttle control while cruising on the freeway when the fuel low level light was on. Both times were several minutes after the light came on.

A. It will drop me out of Cruise Control and I will not be able to accelerate.
B. Car will coast for a few secs (engine still on) and then abruptly I'll have throttle control back again.
C. A few secs later I will lose throttle control again.
D. This cylce repeats.

Both times I pulled over to a gas station and filled her up with gas. Issue disappears after that.

I am thinking it must be a fueling issue but can't figure out what it may be? I haven't touched the fuel system since the Innovate Supercharger and Deatschwerks Fuel Pump install 3-4 months ago.

The car runs perfectly otherwise. AFR's are spot on. Fuel trims look good. No hesitations or loss of fuel to the engine when the tank is filled. No codes.

xjohnx · 08-30-2013, 03:45 PM

Quote:

Originally Posted by sw20kosh

This is a weird question that maybe someone here who has modified their ecu + fuel system has a simple answer to.

Twice now I have lost throttle control while cruising on the freeway when the check engine light was on. Both times were several minutes after the light came on.

A. It will drop me out of Cruise Control and I will not be able to accelerate.
B. Car will coast for a few secs (engine still on) and then abruptly I'll have throttle control back again.
C. A few secs later I will lose throttle control again.
D. This cylce repeats.

Both times I pulled over to a gas station and filled her up with gas. Issue disappears after that.

I am thinking it must be a fueling issue but can't figure out what it may be? I haven't touched the fuel system since the Innovate Supercharger and Deatschwerks Fuel Pump install 3-4 months ago.

The car runs perfectly otherwise. AFR's are spot on. Fuel trims look good. No hesitations or loss of fuel to the engine when the tank is filled. No codes.

how's the rail fuel pressure look?

s2d4 · 08-30-2013, 03:50 PM

probably due to the shape of the fuel tank.

Sportsguy83 · 08-30-2013, 03:55 PM

Quote:

Originally Posted by s2d4

probably due to the shape of the fuel tank.

It doesn't make sense that it happens at cruising. If it were going sideways on the track ok, but cruising it should have nothing to do with tank shape.

Dezoris · 08-30-2013, 03:57 PM

Log when it happens is timing getting axed?

King Tut · 08-30-2013, 07:15 PM

What is the Check Engine Light you are getting when this process starts?

sw20kosh · 08-30-2013, 07:32 PM

Quote:

Originally Posted by King Tut

What is the Check Engine Light you are getting when this process starts?

Sorry typo. Meant to say Fuel Low light.

mike the snake · 08-30-2013, 08:10 PM

Sounds to me like your fuel level meter maybe didn't go back in correctly and even though it shows you having a little fuel left, you're actually running out of fuel.

That would explain why it works fine while the gas light isn't on.

Grymm86 · 08-30-2013, 09:39 PM

Do you usually fill the take completely after this happens? If your fitting over 12.5 gallons your fuel light might be coming on a little late. Mine comes on after about 10.5 gallons.

sw20kosh · 08-31-2013, 12:08 AM

When I filled up the last two times when this happened, it only filled up to 10.2 - 10.5

I will data log it but have to wait till fuel is low.

Dezoris · 08-31-2013, 12:46 AM

Quote:

Originally Posted by sw20kosh

When I filled up the last two times when this happened, it only filled up to 10.2 - 10.5

I will data log it but have to wait till fuel is low.

If it it is ecu, fuel or timing related you will see it. Could be mechanical/pump related too. But log and check first before taking anything apart.

evo4g63 · 08-31-2013, 02:23 AM

Quote:

Originally Posted by Dezoris

If it it is ecu, fuel or timing related you will see it. Could be mechanical/pump related too. But log and check first before taking anything apart.

+1

ft_sjo · 08-31-2013, 02:51 AM

Are you running RaceROM?

sw20kosh · 08-31-2013, 03:42 AM

Quote:

Originally Posted by ft_sjo

Are you running RaceROM?

Yes I am. You have a suspicion about something?

08-30-2013, 03:32 PM	#1
sw20kosh Senior Member Join Date: Jul 2012 Drives: 2013 Black FR-S Location: SF Posts: 3,030 Thanks: 881 Thanked 2,014 Times in 990 Posts Mentioned: 153 Post(s) Tagged: 1 Thread(s)	Odd Gremlin with Fuel Light ON This is a weird question that maybe someone here who has modified their ecu + fuel system has a simple answer to. Twice now I have lost throttle control while cruising on the freeway when the fuel low level light was on. Both times were several minutes after the light came on. A. It will drop me out of Cruise Control and I will not be able to accelerate. B. Car will coast for a few secs (engine still on) and then abruptly I'll have throttle control back again. C. A few secs later I will lose throttle control again. D. This cylce repeats. Both times I pulled over to a gas station and filled her up with gas. Issue disappears after that. I am thinking it must be a fueling issue but can't figure out what it may be? I haven't touched the fuel system since the Innovate Supercharger and Deatschwerks Fuel Pump install 3-4 months ago. The car runs perfectly otherwise. AFR's are spot on. Fuel trims look good. No hesitations or loss of fuel to the engine when the tank is filled. No codes. __________________ 86DRIVE Challenge Last edited by sw20kosh; 08-30-2013 at 07:32 PM.

08-30-2013, 03:57 PM	#5
Dezoris Senior Member Join Date: Aug 2012 Drives: FR-S Location: IL Posts: 2,857 Thanks: 519 Thanked 2,998 Times in 1,095 Posts Mentioned: 159 Post(s) Tagged: 1 Thread(s)	Log when it happens is timing getting axed? __________________ SAVAGEGEESE

08-30-2013, 07:15 PM	#6
King Tut NASA SpecE30 Racer Join Date: May 2012 Drives: 2006 Honda S2000 Location: Gulf Breeze, FL Posts: 7,279 Thanks: 607 Thanked 5,759 Times in 3,055 Posts Mentioned: 274 Post(s) Tagged: 10 Thread(s)	What is the Check Engine Light you are getting when this process starts? __________________ - King Tut Street/Track Car: 2006 Honda S2000 TT3 \|\| Race Car: 1987 BMW 325is SpecE30 \|\| Tow Vehicle: 2014 RAM 1500 EcoDiesel Sold Cars: 2012 BMW M3 \|\| 2013 Subaru BRZ \|\| 2012 Porsche Cayman R \|\| 2009 Chevrolet Z06 \|\| 2009 BMW M3 \|\| 2004 BMW M3 \|\| 2004 Nissan 350Z

08-31-2013, 12:08 AM	#10
sw20kosh Senior Member Join Date: Jul 2012 Drives: 2013 Black FR-S Location: SF Posts: 3,030 Thanks: 881 Thanked 2,014 Times in 990 Posts Mentioned: 153 Post(s) Tagged: 1 Thread(s)	When I filled up the last two times when this happened, it only filled up to 10.2 - 10.5 I will data log it but have to wait till fuel is low. __________________ 86DRIVE Challenge

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08-30-2013, 03:50 PM	#3
s2d4 Senior Member Join Date: Mar 2013 Drives: R32 GTR, AW11 MR2 SC, GTS86 R Location: OZ Posts: 2,615 Thanks: 603 Thanked 1,224 Times in 708 Posts Mentioned: 35 Post(s) Tagged: 0 Thread(s)	probably due to the shape of the fuel tank.

08-30-2013, 08:10 PM	#8
mike the snake Senior Member Join Date: Jul 2013 Drives: 2013 BRZ Location: Norcal Posts: 1,592 Thanks: 1 Thanked 623 Times in 378 Posts Mentioned: 15 Post(s) Tagged: 0 Thread(s)	Sounds to me like your fuel level meter maybe didn't go back in correctly and even though it shows you having a little fuel left, you're actually running out of fuel. That would explain why it works fine while the gas light isn't on.

08-31-2013, 02:51 AM	#13
ft_sjo Banned Join Date: Oct 2012 Drives: GT86 Location: The Motherland Posts: 1,398 Thanks: 140 Thanked 473 Times in 271 Posts Mentioned: 22 Post(s) Tagged: 0 Thread(s)	Are you running RaceROM?

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