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
Sponsored by
Aeromotive Inc

Instant 25 psi fuel pressure drop, whats the cause?

Reply
 
Thread Tools Search this Thread
Old 06-17-2005, 08:22 PM   #1
TECH Apprentice
Garage is empty, add now
 
Trader Rating: 16
Join Date: Apr 2003
Location: Reno, NV
Posts: 396
Default Instant 25 psi fuel pressure drop, whats the cause?

My fuel system had developed a quark. At 5200-5300 rpm my fuel pressure drops from 65-40 instantly. Same spot in the rpm everytime. I havn't changed anything in the system and it used to hold pressure just fine all the way to 6500 rpm. Both pumps are coming on. Any ideas what would cause this?
__________________
2001 WS6. 408 @ 9 psi, 641rwhp @ 5500rpm. Sold 2005
1971 Suburban, LQ4, 4L80E, NP261, 37's. Sold 2014
1993 Mustang LX Hatch 6.0 turbo. New project
BOOSTAT4500 is offline   Reply With Quote
Old 06-19-2005, 11:58 AM   #2
TECH Apprentice
Garage is empty, add now
 
Trader Rating: 16
Join Date: Apr 2003
Location: Reno, NV
Posts: 396
Default

anyone?
__________________
2001 WS6. 408 @ 9 psi, 641rwhp @ 5500rpm. Sold 2005
1971 Suburban, LQ4, 4L80E, NP261, 37's. Sold 2014
1993 Mustang LX Hatch 6.0 turbo. New project
BOOSTAT4500 is offline   Reply With Quote
Old 06-21-2005, 10:50 AM   #3
Staging Lane
Garage is empty, add now
 
MW2 Performance's Avatar
 
Trader Rating: 0
Join Date: Jun 2005
Location: Burbank, CA
Posts: 84
Default

You may have a bad injector, or wiring harness, or the pcm/ yadda yadda, What it sounds like to me is with my experience on my injector cleaning machine, sometimes when I am cleaning a set of injectors that are faulty(either mechanincaly or by contamination) on certain frequencies they will get locked in the open position, and dont come unlocked untill a different frequency is reached, but it could be numerous things.

-Mark
__________________
1998 Firebird Formula, WS6, 1LE, 1 of 14
http://i12.photobucket.com/albums/a2...rs/avatar2.jpg
2006 Suzuki GSX-R 1000
MW2 Performance is offline   Reply With Quote
Old 06-21-2005, 06:24 PM   #4
11 Second Club
Garage is empty, add now
 
BIRDONNOS's Avatar
 
Trader Rating: 3
Join Date: Feb 2004
Location: memphis, tn
Posts: 298
Send a message via AIM to BIRDONNOS Send a message via Yahoo to BIRDONNOS
Default

do u have dual intank pumps if so one of the lines from one of your pumps may have a small leak or tear causing you to lose pressure.
__________________

2004 Hummer H2 Daily Driver
1998 Transam Ramair Fast 90/90, Trickflow 215 heads, 242/248 .610/.615-110 comp cam, T56 Monster Stage 4 Clutch
1968 Pro-Touring Camaro
BIRDONNOS is offline   Reply With Quote
Old 06-21-2005, 09:07 PM   #5
TECH Apprentice
Garage is empty, add now
 
Trader Rating: 16
Join Date: Apr 2003
Location: Reno, NV
Posts: 396
Default

I've looked at the lines on the pumps and they seem Ok, but I'll double check. It's just wierd to me how it's such an instant drop, and always the same rpm. I don't think the injectors lock open cause the car leans out when the pressure drops.
__________________
2001 WS6. 408 @ 9 psi, 641rwhp @ 5500rpm. Sold 2005
1971 Suburban, LQ4, 4L80E, NP261, 37's. Sold 2014
1993 Mustang LX Hatch 6.0 turbo. New project
BOOSTAT4500 is offline   Reply With Quote
Old 06-21-2005, 09:07 PM
LS1Tech
Pontiac Firebird




Paid Advertisement
Reply


Tags
2001, 2002, 50, correct, drop, droping, fuel, lost, ls1, ls1tech, pressure, presure, psi, pump, spec, suburban, trans


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 02:09 PM.


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