how to diagnose a fuel pressure regulator - Page 2 - LS1TECH - Camaro and Firebird Forum Discussion



LT1-LT4 Modifications 1993-97 Gen II Small Block V8

how to diagnose a fuel pressure regulator

Reply
 
Thread Tools Search this Thread
Old 04-06-2009, 08:07 PM   #21
TECH Enthusiast
Thread Starter
 
shutzero's Avatar
 
Join Date: Sep 2008
Location: Cheshire, CT
Posts: 636
Default

Anyone?
shutzero is offline   Reply With Quote
Old 04-06-2009, 08:19 PM   #22
LT1
TECH Fanatic
iTrader: (1)
 
LT1's Avatar
 
Join Date: Sep 2003
Location: NorCal
Posts: 1,608
Default

Quote:
Originally Posted by shutzero View Post
Well is 50 psi a bad fpr? I'm assuming it is, would this also be the reason my car is idling higher than I have it tuned to?
Do you have factory FPR?
50psi is high, should be around 43.5psi
LT1 is offline   Reply With Quote
Old 04-06-2009, 08:20 PM   #23
TECH Enthusiast
Thread Starter
 
shutzero's Avatar
 
Join Date: Sep 2008
Location: Cheshire, CT
Posts: 636
Default

Yes I do have the factory fpr
shutzero is offline   Reply With Quote
Old 04-06-2009, 08:32 PM   #24
LT1
TECH Fanatic
iTrader: (1)
 
LT1's Avatar
 
Join Date: Sep 2003
Location: NorCal
Posts: 1,608
Default

shbox site says what fuel pressure should be, might be worth taking a look. I cant really say if the FPR is bad. Since you don't have fuel on the vacuum side.

http://shbox.com/1/4th_gen_tech2.htm...essure_testing
LT1 is offline   Reply With Quote
Old 04-06-2009, 09:06 PM   #25
TECH Enthusiast
Thread Starter
 
shutzero's Avatar
 
Join Date: Sep 2008
Location: Cheshire, CT
Posts: 636
Default

Yea I don't think there's any fuel coming out of it?
shutzero is offline   Reply With Quote
Old 04-06-2009, 11:07 PM   #26
TECH Enthusiast
Thread Starter
 
shutzero's Avatar
 
Join Date: Sep 2008
Location: Cheshire, CT
Posts: 636
Default

Could this still be the fpr?
shutzero is offline   Reply With Quote
Old 04-07-2009, 02:22 AM   #27
10 Second Club
iTrader: (2)
 
96LT1355Z28's Avatar
 
Join Date: Nov 2007
Location: Holden, MO (KC)
Posts: 798
Default

What does the psi do when your problem occurs on start up? Does it hold psi? 50 is a bit high but shouldn't cause your symptoms.
96LT1355Z28 is offline   Reply With Quote
Old 04-07-2009, 07:02 AM   #28
TECH Enthusiast
Thread Starter
 
shutzero's Avatar
 
Join Date: Sep 2008
Location: Cheshire, CT
Posts: 636
Default

well as it is it idles higher than its set to, but i didnt get it to startup weird with the gauge on
shutzero is offline   Reply With Quote
Old 04-07-2009, 08:51 AM   #29
TECH Addict
iTrader: (1)
 
myltwon's Avatar
 
Join Date: Jul 2004
Location: Palm Harbor, FL
Posts: 2,877
Default

50psi with the vacuum line attached?
myltwon is offline   Reply With Quote
Old 04-07-2009, 09:15 AM   #30
TECH Enthusiast
Thread Starter
 
shutzero's Avatar
 
Join Date: Sep 2008
Location: Cheshire, CT
Posts: 636
Default

Yeah with the vacuum line connected it reads 50 psi when it primes and when it idles
shutzero is offline   Reply With Quote
Old 04-07-2009, 03:39 PM   #31
TECH Enthusiast
Thread Starter
 
shutzero's Avatar
 
Join Date: Sep 2008
Location: Cheshire, CT
Posts: 636
Default

Anyone else?
shutzero is offline   Reply With Quote
Old 04-07-2009, 05:38 PM   #32
Village Troll
iTrader: (2)
 
SS RRR's Avatar
 
Join Date: Oct 2002
Location: Jackstandican
Posts: 9,067
Default

Pressure is way too high for idle and even for WOT. Max pressure w/out vacuum or at WOT should be 43.5psi or between 43 and 45psi.

Last edited by SS RRR; 04-07-2009 at 05:44 PM.
SS RRR is online now   Reply With Quote
Old 04-07-2009, 06:02 PM   #33
Teching In
 
Join Date: Jul 2006
Posts: 8
Cool

Hi, I have same problem, there is not fuel coming out from FPR , the fuel pressure is 50 psi at idle and 60 psi without vacuum line....no fuel inyectors leaking, so I am 99% sure, my fpr is bad. The idle is a little high and some times I have to turn the key 2-3 times to get it start. My fuel pressure drops almost immediately to 0 psi when engine is not runnig.
What other symptoms do you have?
Ger-Fire is offline   Reply With Quote
Old 04-07-2009, 07:22 PM   #34
TECH Enthusiast
Thread Starter
 
shutzero's Avatar
 
Join Date: Sep 2008
Location: Cheshire, CT
Posts: 636
Default

I've just got the high idle and problems starting if I don't prime the car
shutzero is offline   Reply With Quote
Old 04-07-2009, 10:25 PM   #35
TECH Addict
iTrader: (1)
 
myltwon's Avatar
 
Join Date: Jul 2004
Location: Palm Harbor, FL
Posts: 2,877
Default

Quote:
Originally Posted by Ger-Fire View Post
Hi, I have same problem, there is not fuel coming out from FPR , the fuel pressure is 50 psi at idle and 60 psi without vacuum line....no fuel inyectors leaking, so I am 99% sure, my fpr is bad. The idle is a little high and some times I have to turn the key 2-3 times to get it start. My fuel pressure drops almost immediately to 0 psi when engine is not runnig.
What other symptoms do you have?
the pressure dropping to 0 sounds more like a pump related issue
myltwon is offline   Reply With Quote
Old 04-08-2009, 01:16 AM   #36
LT1
TECH Fanatic
iTrader: (1)
 
LT1's Avatar
 
Join Date: Sep 2003
Location: NorCal
Posts: 1,608
Default

If the pressure drops off that quick, would be cause any one of these reasons leaking injector, leaking lines or fittings, leaking FPR, or bad check valve on the pump.
LT1 is offline   Reply With Quote
Old 04-24-2009, 07:03 PM   #37
TECH Enthusiast
Thread Starter
 
shutzero's Avatar
 
Join Date: Sep 2008
Location: Cheshire, CT
Posts: 636
Default

got the new fpr on...i cant tell yet if it fixed the problem but it actually does seem to be idling lower...ill have to throw a tech II on there to read rpms to see if it helped
shutzero is offline   Reply With Quote
Old 04-24-2009, 08:16 PM   #38
TECH Enthusiast
Thread Starter
 
shutzero's Avatar
 
Join Date: Sep 2008
Location: Cheshire, CT
Posts: 636
Default

So the fpr didn't fix the startup problems...any other ideas as to what it could be?
shutzero is offline   Reply With Quote
Old 04-24-2009, 10:12 PM   #39
TECH Enthusiast
Thread Starter
 
shutzero's Avatar
 
Join Date: Sep 2008
Location: Cheshire, CT
Posts: 636
Default

Anyone?
shutzero is offline   Reply With Quote
Old 04-24-2009, 10:29 PM   #40
Launching!
 
Join Date: Dec 2004
Posts: 272
Default

With a fuel pressure gauge hooked up and system primed with engine off does the fuel pressure drop to 0 immediately? If so, I would be willing to bet it is the check valve in the pump.
rkinney is offline   Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
front mount regulator with ls3 rails Ws6Dnero Fueling & Injection 3 11-28-2016 11:39 PM
question with low pressure dedicated kris72079 Nitrous Oxide 7 08-31-2016 03:11 PM
Want to Eliminate intank regulator!! SSClone Fueling & Injection 9 03-06-2016 04:02 PM
Holley fuel pressure regulator dmracing Parts Classifieds 0 08-30-2015 03:24 PM
Someone explain this to me (fuel pressure regulator) dhdenney Fueling & Injection 6 11-24-2009 06:53 PM


Tags
60, bad, check, fuel, fule, hook, lt1, pressure, presure, problems, psi, rail, regulator, unplug, z28

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 Off
Refbacks are Off



All times are GMT -5. The time now is 10:17 AM.


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: