Go Back   LS1TECH > LS1-LS2-LS3-LS6-LS7 PERFORMANCE > Fueling & Injection
Sign in using an external account
Register Forgot Password?
Search

Fueling & Injection
Fuel Pumps | Injectors | Rails | Regulators | Tanks

Pressure fluctuates what to do?

Reply
 
Thread Tools Search this Thread
Old 01-12-2009, 09:08 PM   #1
TECH Apprentice
 
Trader Rating: 0
Join Date: Oct 2006
Location: Wichita, Ks.
Posts: 322
Default Pressure fluctuates what to do?

Recently changed in-tank pumps due to my Aeromotive A1000 starving the pick-up at low volumes. Went with a Bosch pump.
I have 44.5 # injectors, Fast rails and run 58psi.
Now with new pump at 3/4 throttle, accelerating I get a brief pressure drop from 58psi to 52psi. The motor doesn't nose over, I can't tell that it affects it at all. It is a parallel set-up with the regulator behind the injectors.
Should I be concerned? Is this a tuning fix?
My Aeromotive stayed rock solid at 58psi, but it moved alot of fuel.
ss dave is offline   Reply With Quote
Old 01-13-2009, 08:12 AM   #2
FormerVendor
 
Frost's Avatar
 
Trader Rating: 45
Join Date: Jul 2005
Location: Richmond VA
Posts: 5,914
Default

If the pressure drops, the car goes lean unless it was [not the right way to do it] tuned around the pressure drop from the beginning. If it was tuned at a stable 58psi though and it falls now, then the car is leaning out. The PCM cannot see fuel pressure and at heavy to WOT cannot make correction.
Frost is offline   Reply With Quote
Old 01-13-2009, 07:41 PM   #3
LS1TECH Sponsor
 
Lonnies Performance's Avatar
 
Trader Rating: 16
Join Date: Feb 2007
Location: Pittsburgh, PA
Posts: 2,633
Default

Not sure of your exact configuration....

Are you running aftermarket lines?
What brand of regulator?
Is a vac line attached to the regulator & where it is connected?

How long does the the pressure remain low?

Give me some more info & I'll try to help.
__________________
Lonnie Pavtis - Lonnies Performance Automotive
http://www.lonniesperformance.com
Providing High Performance Products & Services since 1999

Specializing in custom fuel systems, fuel injection components, suspension & your supercharging needs.
(724) 322-8505 9:00am-11:00pm (eastern time)weekdays & weekends.

www.lonniesperformance.com/logo3.jpg
Lonnies Performance is offline   Reply With Quote
Old 01-14-2009, 08:47 AM   #4
TECH Apprentice
 
Trader Rating: 0
Join Date: Oct 2006
Location: Wichita, Ks.
Posts: 322
Default

Great, have a modified Ricks mini tub tank which we added extra baffle doors to help with slosh. Recently switched pumps as stated above.

It is a custom parrallel feed/return line set-up. Y block split into two lines that feed the FAST High Flow rails with a Weldon regulator on the return side, I don't think it has a vaccum line- I'll look tonight. Bosch 44.5# injectors.

With the Aeromotive pump I never had fluctuations upon acceleration, but with low fuel volumes in tank and when cornering (slosh) it would starve the pick-up. At fuller tank volumes- no problems. Rock steady pressures. Switched pumps thinking that the Aeromotive was moving alot of fuel so fast that at low volumes it would starve at the pick-up.

Switched pumps and now on 3/4 throttle acceleration I'll get a brief, maybe 1-2 maybe 3second drop in pressure from 58psi to 53 or 52psi, then it recovers.
Thanks for any input.
Dave
ss dave is offline   Reply With Quote
Old 01-14-2009, 11:30 AM   #5
TECH Addict
 
405HP_Z06's Avatar
 
Trader Rating: 11
Join Date: Jun 2003
Location: Arlington, Tx
Posts: 2,205
Send a message via MSN to 405HP_Z06 Send a message via Skype™ to 405HP_Z06
Default

What type of fuel pressure gauge are you using? Is it dampened and/or liquid filled?
__________________
Aaron
EFI-101, EFI Advanced, EFILive-101, Variable Camshaft Tuning
EFI University Evangelist
405HP_Z06 is offline   Reply With Quote
Old 01-14-2009, 01:19 PM   #6
TECH Apprentice
 
Trader Rating: 0
Join Date: Oct 2006
Location: Wichita, Ks.
Posts: 322
Default

I have two, one on the regulator and an Auto Gauge Comp II inside.
ss dave is offline   Reply With Quote
Old 01-14-2009, 04:47 PM   #7
LS1TECH Sponsor
 
Lonnies Performance's Avatar
 
Trader Rating: 16
Join Date: Feb 2007
Location: Pittsburgh, PA
Posts: 2,633
Default

Dave
Is this in the stock bucket?

Is the sock in the bucket or outside?
Is the venturi functioning?

Feel free to call me to discuss.
724-322-8505 until 11:00pm eastern time
__________________
Lonnie Pavtis - Lonnies Performance Automotive
http://www.lonniesperformance.com
Providing High Performance Products & Services since 1999

Specializing in custom fuel systems, fuel injection components, suspension & your supercharging needs.
(724) 322-8505 9:00am-11:00pm (eastern time)weekdays & weekends.

www.lonniesperformance.com/logo3.jpg
Lonnies Performance is offline   Reply With Quote
Old 01-14-2009, 06:06 PM   #8
TECH Apprentice
 
Trader Rating: 0
Join Date: Oct 2006
Location: Wichita, Ks.
Posts: 322
Default

Thanks Lonnie, No sock. Pick -up tube into 10 micron filter. No bucket, just baffling around pick-up tube. Custom Ricks tank into my 69 Camaro with an LS7

.Click the image to open in full size.

Last edited by ss dave; 01-15-2009 at 08:23 AM..
ss dave is offline   Reply With Quote
Old 01-15-2009, 10:03 AM   #9
FormerVendor
 
Frost's Avatar
 
Trader Rating: 45
Join Date: Jul 2005
Location: Richmond VA
Posts: 5,914
Default

uhhhhh

o god, I just got wood
Frost is offline   Reply With Quote
Old 01-15-2009, 10:20 AM   #10
TECH Addict
 
405HP_Z06's Avatar
 
Trader Rating: 11
Join Date: Jun 2003
Location: Arlington, Tx
Posts: 2,205
Send a message via MSN to 405HP_Z06 Send a message via Skype™ to 405HP_Z06
Default

WOW, just WOW. That's awesome.
__________________
Aaron
EFI-101, EFI Advanced, EFILive-101, Variable Camshaft Tuning
EFI University Evangelist
405HP_Z06 is offline   Reply With Quote
Old 01-15-2009, 02:58 PM   #11
TECH Apprentice
 
Trader Rating: 0
Join Date: Oct 2006
Location: Wichita, Ks.
Posts: 322
Default

Thanks, now if I can fine tune this psi stuff, I'll sleep better
Click the image to open in full size.
ss dave is offline   Reply With Quote
Old 01-15-2009, 03:11 PM   #12
FormerVendor
 
Frost's Avatar
 
Trader Rating: 45
Join Date: Jul 2005
Location: Richmond VA
Posts: 5,914
Default

guh, goo


VERY NICE
Frost is offline   Reply With Quote
Old 01-15-2009, 06:46 PM   #13
LS1TECH Sponsor
 
Lonnies Performance's Avatar
 
Trader Rating: 16
Join Date: Feb 2007
Location: Pittsburgh, PA
Posts: 2,633
Default

Nice ride!!!!

But based on the info I can not determine your configuration.
Give me a call sometime.
__________________
Lonnie Pavtis - Lonnies Performance Automotive
http://www.lonniesperformance.com
Providing High Performance Products & Services since 1999

Specializing in custom fuel systems, fuel injection components, suspension & your supercharging needs.
(724) 322-8505 9:00am-11:00pm (eastern time)weekdays & weekends.

www.lonniesperformance.com/logo3.jpg
Lonnies Performance is offline   Reply With Quote
Old 01-15-2009, 10:35 PM   #14
TECH Apprentice
 
Trader Rating: 0
Join Date: Oct 2006
Location: Wichita, Ks.
Posts: 322
Default

Thanks Lonnie. I'll have my FI guru call ya.
Gauges at idle.
Click the image to open in full size.
Click the image to open in full size.

Last edited by ss dave; 01-15-2009 at 10:47 PM..
ss dave is offline   Reply With Quote
Old 01-15-2009, 10:35 PM
LS1Tech
Pontiac Firebird




Paid Advertisement
Reply


Tags
aeromotive, fluctuates, fuel, ls1tech, pressure


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off



Join Ls1Tech

All times are GMT -5. The time now is 09:40 AM.


Powered by vBulletin® Version 3.8.7 AC1
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Advertising - Terms of Service - Privacy Statement - Terms of Service - JOBS
Emails & Contact Details