Go Back  RX7Club.com - Mazda RX7 Forum > Tech and Performance > Race Car Tech
Reload this Page >

odd fuel starvation issues on left turns even with surge tank

Race Car Tech Discuss anything related to road racing and auto X.

odd fuel starvation issues on left turns even with surge tank

Old 08-20-18, 09:55 PM
  #1  
rotard
Thread Starter
iTrader: (15)
 
Spirit Rx-7's Avatar
 
Join Date: Feb 2003
Location: Los Angeles
Posts: 1,313
Likes: 0
Liked 3 Times in 1 Post
odd fuel starvation issues on left turns even with surge tank

just thought i'd share this if anyone else have any ideas. i've track my car with this set up for over 30 track events. it used to only starve when just start entering the track if its a left turn entrance, after that all else good, so i didn't bother diagnosing it.

now recently its happening all the time at the track now during left turns. my set up is a 034 motorsports external surge tank mounted outside under vehicle with a bosch 044 pump. in tank fuel pump is a aeromotive stealth 340. fuel filter is a relocated fuel lab filter that was just cleaned. i just replaced the surge tank pump few days ago, and still have this problem last weekend. voltage on the pumps are 12.6 with key on, and has its own separate relay to battery. i also noticed its worst when its hot outside. any suggestions? my guess would be to replace in tank pump next?

my car set up is a fd single turbo efr 7670, 500 primary's, 1300 secondaries
Spirit Rx-7 is offline  
Old 08-22-18, 09:16 AM
  #2  
Long time on-looker
iTrader: (33)
 
Join Date: Oct 2005
Location: Columbus, OH
Posts: 835
Liked 16 Times in 16 Posts
in-tank pump on the stock hangar and stock location? I'd think it would need to starve for quite a while though to lower the level in the surge tank enough to have that also pump air. Any pictures of the setup?
Smokey The Talon is offline  
Old 08-22-18, 08:55 PM
  #3  
rotard
Thread Starter
iTrader: (15)
 
Spirit Rx-7's Avatar
 
Join Date: Feb 2003
Location: Los Angeles
Posts: 1,313
Likes: 0
Liked 3 Times in 1 Post
Originally Posted by Smokey The Talon View Post
in-tank pump on the stock hangar and stock location? I'd think it would need to starve for quite a while though to lower the level in the surge tank enough to have that also pump air. Any pictures of the setup?
yup, in-tank pump on stock hanger and stock location. but wiring from pump is not stock, power and ground goes up separately through the bulkhead with nylon bulkhead fittings. i shall try to get some pics when i remove it for new pump. its just weird that is happening now everytime since 2015, before it was tolerable at the track, now car is totally undriveable, makes me want to go back to stock set up without surge tank.
Spirit Rx-7 is offline  
Old 08-24-18, 03:41 PM
  #4  
Long time on-looker
iTrader: (33)
 
Join Date: Oct 2005
Location: Columbus, OH
Posts: 835
Liked 16 Times in 16 Posts
Double check all your connections that are submerged in fuel. If you donít have any then look at the pump sock or pickup points for issues. . When I tried to run an in-tank surge tank the hose from the pump to tank kept coming loose and sucking air driving me crazy. I went back to the later-spec stock sump cover and hydramat stuffed in there.

What tires do you run and what level is the fuel when starving?
Smokey The Talon is offline  
Old 08-26-18, 08:32 PM
  #5  
RE for life
 
diyman25's Avatar
 
Join Date: May 2002
Location: sca
Posts: 1,173
Likes: 0
Liked 17 Times in 14 Posts
Check ur relay, this happend to me too luckily is on dyno, right now too many aftermarket relay's quality is pretty bad
diyman25 is offline  
Old 08-27-18, 01:48 PM
  #6  
rotard
Thread Starter
iTrader: (15)
 
Spirit Rx-7's Avatar
 
Join Date: Feb 2003
Location: Los Angeles
Posts: 1,313
Likes: 0
Liked 3 Times in 1 Post
Originally Posted by Smokey The Talon View Post
Double check all your connections that are submerged in fuel. If you donít have any then look at the pump sock or pickup points for issues. . When I tried to run an in-tank surge tank the hose from the pump to tank kept coming loose and sucking air driving me crazy. I went back to the later-spec stock sump cover and hydramat stuffed in there.

What tires do you run and what level is the fuel when starving?
thanks i shall check that when i have it apart today. my connection points pretty much stock set up.

im on street tires, 200 treadware requirement for my class i run in. i starve even at full tank now, especially when its hot. before it used to be just under a quarter tank and left turns.
Spirit Rx-7 is offline  
Old 08-27-18, 01:50 PM
  #7  
rotard
Thread Starter
iTrader: (15)
 
Spirit Rx-7's Avatar
 
Join Date: Feb 2003
Location: Los Angeles
Posts: 1,313
Likes: 0
Liked 3 Times in 1 Post
Originally Posted by diyman25 View Post
Check ur relay, this happend to me too luckily is on dyno, right now too many aftermarket relay's quality is pretty bad
thanks, i will test both my relays for each pump, and have lucky7 look at the wiring again
Spirit Rx-7 is offline  
Old 08-27-18, 03:59 PM
  #8  
Long time on-looker
iTrader: (33)
 
Join Date: Oct 2005
Location: Columbus, OH
Posts: 835
Liked 16 Times in 16 Posts
I'm betting something is disconnected inside the stock tank/stock setup if it's doing it with a full tank on 200tw tires.
Smokey The Talon is offline  
Old 09-03-18, 12:50 PM
  #9  
Money talks.Mine says bye
iTrader: (18)
 
cone_crushr's Avatar
 
Join Date: May 2005
Location: LBC, CA
Posts: 673
Liked 0 Times in 0 Posts
Is it possible that you have an air-pocket (bubble) in the surge tank? Presumably you're detecting starvation with a fuel pressure gage. Do you have a fuel temp gage also?

Last edited by cone_crushr; 09-03-18 at 01:14 PM.
cone_crushr is offline  
Old 09-04-18, 12:43 AM
  #10  
rotard
Thread Starter
iTrader: (15)
 
Spirit Rx-7's Avatar
 
Join Date: Feb 2003
Location: Los Angeles
Posts: 1,313
Likes: 0
Liked 3 Times in 1 Post
Originally Posted by cone_crushr View Post
Is it possible that you have an air-pocket (bubble) in the surge tank? Presumably you're detecting starvation with a fuel pressure gage. Do you have a fuel temp gage also?
thats what i was also thinking, but wouldn't it go away after a few runs? its been removed and reinstalled numerous times, and i prime it before starting. and nahh, no fuel temp gauge unfortunately

as of now, i replaced main intank pump with walbro 400, new surge pump bosh044, replaced both pump relays. now just need to do a shake down somewhere
Spirit Rx-7 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
dj55b
1st Generation Specific (1979-1985)
12
01-24-09 06:14 PM
mike horner
Race Car Tech
19
08-19-07 01:18 PM
MtotheIKEo
1st Generation Specific (1979-1985)
4
07-22-07 11:28 PM


Thread Tools
Search this Thread
Quick Reply: odd fuel starvation issues on left turns even with surge tank


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: