STILL lOOSING FUEL PRESSURE??? - Team Camaro Tech
Troubleshooting Diagnosing problems done here.

 
LinkBack Thread Tools Display Modes
post #1 of 11 (permalink) Old Dec 9th, 06, 05:25 AM Thread Starter
Senior Tech
Brian
 
Join Date: Jan 2003
Location: Georgia
Posts: 276
Unhappy STILL lOOSING FUEL PRESSURE???

The following items are new: all new motor, new carb/new holley electric pump/new regulator/all new fuel lines 3/8/new gas tank/new sending unit/new sock,new gas cap vented, I also vented the tank. When cold the gas pressure gauge reads 6lbs, when it heats up it drops to 3. This is the 5th fuel pump, my only other options I can think of is to change the fuel pressure gauge or change the regulator to allow a return line. Any ideas, this has been going on for months and nobody has been able to figure it out?
paperman is offline  
Sponsored Links
Advertisement
 
post #2 of 11 (permalink) Old Dec 9th, 06, 05:48 AM
Gold Lifetime Member
Kevin
 
SixtyAte's Avatar
 
Join Date: May 2005
Location: S. Eastern Massachusetts
Posts: 5,536
Re: STILL lOOSING FUEL PRESSURE???

I would disconnect the line from the carb and tank. Block the end of the line at the tank then put an adapter to be able to add air pressure to the line from the tank to the carb. Something with a gauge and it needs to be able to hold pressure. Pump it up to 6 lbs and see if it leaks down. After trying that and if it still leaks down. ,at each joint, connection, regulator etc, track back until the system holds pressure. You will then find the weak point.

Kev
SixtyAte is offline  
post #3 of 11 (permalink) Old Dec 9th, 06, 08:29 AM
Gold Lifetime Member
Don
 
Join Date: Jan 2005
Location: 2 Dog Town in West Texas
Posts: 11,152
Re: STILL lOOSING FUEL PRESSURE???

Also check to see if needle/seats too high or leaking. Or even a bad guage. I had lots of these, jegs, russell, summit, liquid filled. Pump bypassing?
I did loose a pump lobe.

Don
TC # 349
Zdld17:69 Z/RS,306, NOR141111, 9N554XXX, 12A, X3G, 59/59,723, AFR 195,CCC282/290HR, TKO 600, BU1122B1E Owner since Dec 1968

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
zdld17 is offline  
 
post #4 of 11 (permalink) Old Dec 9th, 06, 08:55 AM Thread Starter
Senior Tech
Brian
 
Join Date: Jan 2003
Location: Georgia
Posts: 276
Re: STILL lOOSING FUEL PRESSURE???

Do you think it is possible to be loosing voltage to the pump?
paperman is offline  
post #5 of 11 (permalink) Old Dec 29th, 06, 07:10 AM
Senior Tech
Dave
 
Join Date: Oct 2005
Location: Rhode Island
Posts: 1,356
Re: STILL lOOSING FUEL PRESSURE???

Damn, you guys are killing me, LOL. It's "LOSE", as in "losing fuel pressure", not "LOOSE"......................

Lemme ask; does the car act as though it's running lean at WOT?????? Have you had it on a chassis dyno to check performance and A/F ratios?

-

Dave F. in Rhode Island
'68 Camaro SS Accel DFI 454 (SOLD - I'm a boring Corvette owner now)
Bought my first big-block Chevy in 1970
Chevy-SS is offline  
post #6 of 11 (permalink) Old Dec 29th, 06, 12:34 PM Thread Starter
Senior Tech
Brian
 
Join Date: Jan 2003
Location: Georgia
Posts: 276
Re: STILL lOOSING FUEL PRESSURE???

After changing fuel pump and regulator, creating a return line it was still doing it. Called holley tech line, turns out liguid filled pressure gauges under engine heat act like my symtems. Replaced with non liquid filled, couple hundred dollars later turns out a 15 dollar gauge is the problem. All my toughest lessons are learned monetarily.
paperman is offline  
post #7 of 11 (permalink) Old Dec 29th, 06, 06:20 PM
Gold Lifetime Member
Bruno
 
Join Date: Oct 2000
Location: Puerto Rico
Posts: 2,118
Lightbulb Re: STILL lOOSING FUEL PRESSURE???

Quote:
Originally Posted by paperman View Post
After changing fuel pump and regulator, creating a return line it was still doing it. Called holley tech line, turns out liguid filled pressure gauges under engine heat act like my symtems. Replaced with non liquid filled, couple hundred dollars later turns out a 15 dollar gauge is the problem. All my toughest lessons are learned monetarily.
Sorry I came with my reply a little too late, but those liquid filled gauges are tricky. I'm still using mine, but needed to bleed some air pressure from it, a couple of times, before the darn gauge stopped doing that. Seems like if the emvironment pressure is different where they are manufactured, than where one uses it, and it needs to equalize the pressure inside the gauge with the outside pressure. Mine is working perfectly for a couple of years now after this procedure. Yours got to have a little rubber plug, that's what I use to bleed air from it, when hot.

"Our affair with Camaros is a life sentence without the possibility of parole".
ORENCH is offline  
post #8 of 11 (permalink) Old Jan 7th, 07, 12:58 PM
Tech Team
Rob
 
Join Date: Jan 2006
Location: Toronto, Canada
Posts: 58
Re: STILL lOOSING FUEL PRESSURE???

I had samne probelm with a liquid filled unit and went back to the mechanical.. So,ORENCH, how did u bled the pressure down to the level that worked?

'67 Rag Top, 350, Th 350, Frame off resto to an SS clone
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
hurdslake is offline  
post #9 of 11 (permalink) Old Jan 9th, 07, 03:03 AM
Gold Lifetime Member
Bruno
 
Join Date: Oct 2000
Location: Puerto Rico
Posts: 2,118
Thumbs up Re: STILL lOOSING FUEL PRESSURE???

Quote:
Originally Posted by hurdslake View Post
I had samne probelm with a liquid filled unit and went back to the mechanical.. So,ORENCH, how did u bled the pressure down to the level that worked?
Thru the small rubber plug on top of the gauge. With a lot of technically advanced use of my "index" finger's nail.

"Our affair with Camaros is a life sentence without the possibility of parole".
ORENCH is offline  
post #10 of 11 (permalink) Old Jan 10th, 07, 01:04 PM
Senior Tech
Marc
 
Join Date: Jun 2001
Location: Cedar Rapids, IA
Posts: 734
Re: STILL lOOSING FUEL PRESSURE???

I went through two Jegs liquid filled gauges with the same problem. I bought an electric one which works perfect. I will try bleeding off one of these liquid filled ones and see if I can get it to work.

Marc


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


67 Camaro, 454, TH400, 9" 4.11's
camaro man is offline  
post #11 of 11 (permalink) Old Jan 10th, 07, 01:49 PM Thread Starter
Senior Tech
Brian
 
Join Date: Jan 2003
Location: Georgia
Posts: 276
Re: STILL lOOSING FUEL PRESSURE???

You would think the manufactorers would say something about bleeding it down in the instructions as a maintenance issue or correcting it with a fluid that works?
paperman is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
checking fuel pressure goldyiroc Camaro Tech 1 Jan 13th, 06 12:01 PM
Fuel pressure keeps dropping, any ideas ? jaytone Camaro Tech 9 Jun 4th, 05 09:02 PM
Erratic fuel pressure reading?? Joe 69 Engine 5 Aug 19th, 03 03:30 PM
Fuel Pressure txwindsurf Tech 2000 4 Jul 13th, 01 03:00 AM
Fuel Pressure 68SS502 Tech 2000 2 Dec 6th, 00 11:17 AM

Posting Rules  
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome