December 10, 2019, 07:26:41 PM

Author Topic: Fuel slosh.... need help/opinions  (Read 2321 times)

Offline Skeltic

Re: Fuel slosh.... need help/opinions
« Reply #15 on: June 06, 2019, 03:53:43 PM »
I will also add I bought  a big one 750$, and my tanks baffles broke so  I took them out so I have really good access to the bottom of the tank
"You can sleep in your car, but you can't race your house."

Offline Supe

Re: Fuel slosh.... need help/opinions
« Reply #16 on: June 06, 2019, 04:53:31 PM »
I will also add I bought  a big one 750$, and my tanks baffles broke so  I took them out so I have really good access to the bottom of the tank

Thanks.  I have a small square ATL cell, so was looking at the 11x11 one.

Offline paul_3rdgen

  • Supporting Member
  • Launching!
  • Location: Canada
  • Posts: 1145
  • View Gallery
    • View Profile
Re: Fuel slosh.... need help/opinions
« Reply #17 on: June 08, 2019, 12:42:35 PM »
So far I scanned the pcm, no dtcís present.  So like I thought, not an ignition problem.   Next Iíll pull the pump assembly to see what I find. 


Sent from my iPhone using Tapatalk
93 RX7 R1 500rwhp
LS2, H/C combo... ARE drysump
Race Logic traction Control and 4 wheel Stoptech BBK
3.73 gears installed in the stock diff  :o

Offline Exidous

Re: Fuel slosh.... need help/opinions
« Reply #18 on: June 08, 2019, 01:34:29 PM »
Agree with Exidous, I had the same problem. Spent alot of money on surge tanks aux pumps pressure regs and gauges,no bueno. Holly fuel mat Hydramat solved it. Now it will run  till out of gas. But when its out of gas it is REALLY out of gas

Any issues with the hydramat?  How long have you been using it?  Wondering how they do longevity wise.  I only have an 8 gallon cell, and with the corner pickup, I get fuel starve issues with about 3 gallons left!

It's been in there for some time now. About 6 months after they released it. No issues at all. I've used it at Spa, Brands Hatch and the Ring. Never had an issue. I am running some cell foam to help with slosh as well.
94 BB SBE LS1 Full Mamo top, MS3ProU with TC, RONIN 8.8 and another custom dual 2.5" stainless exhaust. Not too loud with the new resonators!

Offline paul_3rdgen

  • Supporting Member
  • Launching!
  • Location: Canada
  • Posts: 1145
  • View Gallery
    • View Profile
Re: Fuel slosh.... need help/opinions
« Reply #19 on: June 10, 2019, 05:50:59 PM »
Pulled the pump assembly..... everything looks perfect.   So before I started I unscrewed the gas cap, I noticed the tank is holding pressure..... is this normal?   Or could my tank venting be the problem?


Sent from my iPhone using Tapatalk
93 RX7 R1 500rwhp
LS2, H/C combo... ARE drysump
Race Logic traction Control and 4 wheel Stoptech BBK
3.73 gears installed in the stock diff  :o

Online MPbdy

Re: Fuel slosh.... need help/opinions
« Reply #20 on: June 10, 2019, 06:17:58 PM »
You still have the charcoal canister?  My gas cap always had a low of pressure behind it until I got rid of it.

Offline paul_3rdgen

  • Supporting Member
  • Launching!
  • Location: Canada
  • Posts: 1145
  • View Gallery
    • View Profile
Re: Fuel slosh.... need help/opinions
« Reply #21 on: June 10, 2019, 06:20:44 PM »
No charcoal canister, but i left the lines on the tank the way they were.  What Iím suspecting is that the one way check valves are not letting pressure out because they need vacuum to open them.   I guess since I was pushing the car to the limits I found this issue, as I havenít noticed this while street driving. 


Sent from my iPhone using Tapatalk
93 RX7 R1 500rwhp
LS2, H/C combo... ARE drysump
Race Logic traction Control and 4 wheel Stoptech BBK
3.73 gears installed in the stock diff  :o

Online MPbdy

Re: Fuel slosh.... need help/opinions
« Reply #22 on: June 10, 2019, 06:59:33 PM »
Mine would pressurize just driving on the street.

I ran the vent line to a small fuel filter for a lawn mower.  Doesn't have a smell or anything, and no more pressure behind my gas cap.

I do still get fuel slosh cutting my engine out if the tank is low.  If it were a rotary I'd probably have destroyed it by now.  It happens to me almost every tank of gas since I'm always getting on it lol. 

https://www.amazon.com/Briggs-Stratton-691035-Selected-Engines/dp/B0035PVVBY/ref=asc_df_B0035PVVBY/?tag=hyprod-20&linkCode=df0&hvadid=167133658256&hvpos=1o1&hvnetw=g&hvrand=8085289982636457772&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031526&hvtargid=pla-316285016395&psc=1

Offline paul_3rdgen

  • Supporting Member
  • Launching!
  • Location: Canada
  • Posts: 1145
  • View Gallery
    • View Profile
Re: Fuel slosh.... need help/opinions
« Reply #23 on: August 01, 2019, 06:29:41 PM »
So, first I put in the filters Daniel mentioned, that worked to solve the venting issues from what I can tell, no pressure when opening gas cap anymore.   Second I swapped in a spare supra pump I had, now I have 53psi not 58psi like I should but it doesnít drop off like it was. 

I ran out of time and patience due to everyday family life so I dropped it off at a friends shop to figure it out.  Iíll report back.  Heís also going to do a leak down to make sure I didnít do any damage while I was at the track. 

Canít test the car in the evenings anymore due to the kids sleeping right above the garage.


Sent from my iPhone using Tapatalk
93 RX7 R1 500rwhp
LS2, H/C combo... ARE drysump
Race Logic traction Control and 4 wheel Stoptech BBK
3.73 gears installed in the stock diff  :o

Offline Exidous

Re: Fuel slosh.... need help/opinions
« Reply #24 on: August 05, 2019, 02:51:54 PM »

Can’t test the car in the evenings anymore due to the kids sleeping right above the garage.


Well that just sounds like poor planning. When are you able to work on the car? While the kids are asleep.
94 BB SBE LS1 Full Mamo top, MS3ProU with TC, RONIN 8.8 and another custom dual 2.5" stainless exhaust. Not too loud with the new resonators!

Offline paul_3rdgen

  • Supporting Member
  • Launching!
  • Location: Canada
  • Posts: 1145
  • View Gallery
    • View Profile
Re: Fuel slosh.... need help/opinions
« Reply #25 on: August 06, 2019, 06:30:32 PM »
I know.  But life changes and so do our priorities when we have kids. 

On another note, compression numbers are good.... Compression results
1- 240, 3- 238, 5- 238, 7- 235
2- 238, 4- 238, 6-230, 8- 235

Changed fpr, no change..... now onto the voltage test. 




Sent from my iPhone using Tapatalk
93 RX7 R1 500rwhp
LS2, H/C combo... ARE drysump
Race Logic traction Control and 4 wheel Stoptech BBK
3.73 gears installed in the stock diff  :o

Offline paul_3rdgen

  • Supporting Member
  • Launching!
  • Location: Canada
  • Posts: 1145
  • View Gallery
    • View Profile
Re: Fuel slosh.... need help/opinions
« Reply #26 on: August 07, 2019, 08:52:52 PM »
Progress...... looks like the alternator is on its way out. 



More testing after the new alternator goes in. 


Sent from my iPhone using Tapatalk
93 RX7 R1 500rwhp
LS2, H/C combo... ARE drysump
Race Logic traction Control and 4 wheel Stoptech BBK
3.73 gears installed in the stock diff  :o

Online digitalsolo

  • Administrator
  • Top Fuel
  • Location: Fort Wayne, IN
  • Posts: 22869
  • View Gallery
    • View Profile
    • LS1FC.com
Re: Fuel slosh.... need help/opinions
« Reply #27 on: August 07, 2019, 10:17:02 PM »
Oof, that'll do it.
Blake MF'ing McBride
1988 Mazda RX7 - Turbo LS1/T56/ProEFI/8.8/Not Slow...   sold.
1965 Mustang Coupe - TT Coyote, TR6060, modern brakes/suspension...  project car
2016 BMW 428i xDrive Gran Coupe - Completely stock...ish

Offline paul_3rdgen

  • Supporting Member
  • Launching!
  • Location: Canada
  • Posts: 1145
  • View Gallery
    • View Profile
Re: Fuel slosh.... need help/opinions
« Reply #28 on: August 13, 2019, 06:40:00 PM »
Update!  Alternator was not the issue!  Accessory power wire was dropping power.  Not sure why yet but not the only issue!  I tapped my lingenfelter trigger module into the constant ecu power= bad idea!  Gotta fix that too.  Question is why is this all happening 4 years after I completed my second ls swap on this car.   
Accessory fixed.... you can see the improvement.


Sent from my iPhone using Tapatalk
93 RX7 R1 500rwhp
LS2, H/C combo... ARE drysump
Race Logic traction Control and 4 wheel Stoptech BBK
3.73 gears installed in the stock diff  :o

Offline gnx7

Re: Fuel slosh.... need help/opinions
« Reply #29 on: August 13, 2019, 11:06:55 PM »
Maybe go bonkers and do a Radium surge tank :)
'93 FD: 441ci/AllPro LS7 heads/intake en route, T56 Mag, 8.8" IRS, HolleyHP, DavisTechTC 10.32@137mph cats/full exhaust. 165mph 1/2 mile (old LS7)
'93 FD LS9 turbo, T56 Mag, Samberg 8.8" solid axle, 9.35@163mph 197mph 1/2 mile
`69 Chevelle: alum 5.3, GTS76 turbo, ChiseledPerf A/W, T56 Magnum,Ford 35 spline 9".CTS-V interior http://www.norotors.com/index.php?topic=18234.0
old yellar....440rwhp/FD sold but not forgotten: http://www.ponycars.net/scc.htm
I sell new T56 Magnums/McLeod clutch/T56 rebuild kits/Holley EFI/FIC injectors and all BrianTooleyRacing parts.  norcalmotorsport@gmail.com