Go Back   986 Forum - for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Boxster General Discussions

Reply
 
LinkBack Thread Tools Display Modes
Old 09-09-2019, 06:19 AM   #1
Vza
Registered User
 
Join Date: Oct 2018
Location: Nj
Posts: 31
Fuel reassure Test

Hi all, 99 Boxster Base. P1123...P1125 CEL's

Did fuel pressure test and results are:

Engine Off 3.3Bar

Idle: 3.1 Bar

Question, with engine off (after running and shut down) the fuel pressure was 2.6 Bars if I let it sit... it crept up to 3.4 Bars...... which is the accurate reading?

Also....when replacing the fuel rail cap on the schrader valve I over torqued it with my cheapo torque wrench and popped the top of the cap and scored the top of the fuel rail with the bottom of the cap totally trashing the cap. Is this an issue I have to worry about. The valve seemed good and didn't leak...only a slight score or scratch at the base. Can I just replace the cap and move on. Thanks V
Vza is offline   Reply With Quote
Old 09-09-2019, 06:57 AM   #2
Registered User
 
Join Date: Feb 2005
Location: It's a kind of magic.....
Posts: 5,123
The higher reading.

Nominal values should be 3.8 bar +/- 0.2 engine off, 3.3+/-0.2 idling

You need to replace the brass cap.
__________________
Anything really new is invented only in one’s youth. Later, one becomes more experienced, more famous – and more stupid.” - Albert Einstein
JFP in PA is offline   Reply With Quote
Old 09-09-2019, 10:03 AM   #3
Vza
Registered User
 
Join Date: Oct 2018
Location: Nj
Posts: 31
Thanks for the reply JFP ...OK...so I'm low and out of range at 3.4 with engine off and low at 3.1 but with in range at idle. Is this okay or does the fuel pressure regulator need to be replaced to remedy the 1123....1125 codes??

I ordered the new cap already...as I said I scored/scratched the base of the schrader valve by over torquing, it seems the brass cap is designed to strip before doing any damage to the rail..it doesn't leak ....am I good with just replacing the cap.
Thanks V
Vza is offline   Reply With Quote
Old 09-09-2019, 10:28 AM   #4
Registered User
 
Join Date: Feb 2005
Location: It's a kind of magic.....
Posts: 5,123
Quote:
Originally Posted by Vza View Post
Thanks for the reply JFP ...OK...so I'm low and out of range at 3.4 with engine off and low at 3.1 but with in range at idle. Is this okay or does the fuel pressure regulator need to be replaced to remedy the 1123....1125 codes??

I ordered the new cap already...as I said I scored/scratched the base of the schrader valve by over torquing, it seems the brass cap is designed to strip before doing any damage to the rail..it doesn't leak ....am I good with just replacing the cap.
Thanks V
Have you completed the vacuum test of the regulator, and did it pass?
__________________
Anything really new is invented only in one’s youth. Later, one becomes more experienced, more famous – and more stupid.” - Albert Einstein
JFP in PA is offline   Reply With Quote
Old 09-09-2019, 12:11 PM   #5
Vza
Registered User
 
Join Date: Oct 2018
Location: Nj
Posts: 31
OK....Thats new to me....read only to check fuel pressure. Will move on to vacuum testing regulator. BTW are my fuel # ok? No worries about the scored fuel rail?? I didn't see a vacuum test for the regulator in the shop man is it in the Bentley book??

Last edited by Vza; 09-09-2019 at 12:20 PM.
Vza is offline   Reply With Quote
Old 09-09-2019, 01:45 PM   #6
Registered User
 
Join Date: Feb 2005
Location: It's a kind of magic.....
Posts: 5,123
Quote:
Originally Posted by Vza View Post
OK....Thats new to me....read only to check fuel pressure. Will move on to vacuum testing regulator. BTW are my fuel # ok? No worries about the scored fuel rail?? I didn't see a vacuum test for the regulator in the shop man is it in the Bentley book??
No, but it is in the Porsche OBD II code diagnostics manual for the car.

One pressure is a bit low.

If the rail isn't leaking, it should be fine.
__________________
Anything really new is invented only in one’s youth. Later, one becomes more experienced, more famous – and more stupid.” - Albert Einstein
JFP in PA is offline   Reply With Quote
Old 09-09-2019, 06:43 PM   #7
Vza
Registered User
 
Join Date: Oct 2018
Location: Nj
Posts: 31
Well I don't have access to the OBD manual. Can anyone point me to instructions on doing a vacuum test on fuel pressure regulator. Couldn't find anything. V
Vza is offline   Reply With Quote
Old 09-10-2019, 01:24 AM   #8
Registered User
 
Join Date: Feb 2005
Location: It's a kind of magic.....
Posts: 5,123
Quote:
Originally Posted by Vza View Post
Well I don't have access to the OBD manual. Can anyone point me to instructions on doing a vacuum test on fuel pressure regulator. Couldn't find anything. V
Ummmmmmmmmmmmmm......Put a tee in the vacuum line at the regulator, hook up a vacuum gauge, start car and let idle, read gauge...............
__________________
Anything really new is invented only in one’s youth. Later, one becomes more experienced, more famous – and more stupid.” - Albert Einstein
JFP in PA is offline   Reply With Quote
Old 09-10-2019, 06:47 AM   #9
Vza
Registered User
 
Join Date: Oct 2018
Location: Nj
Posts: 31
I figured you'd know. So I'm measuring vacuum being pulled from FPR correct? Thanks V
Vza is offline   Reply With Quote
Old 09-10-2019, 08:16 AM   #10
Registered User
 
Join Date: Feb 2005
Location: It's a kind of magic.....
Posts: 5,123
Quote:
Originally Posted by Vza View Post
I figured you'd know. So I'm measuring vacuum being pulled from FPR correct? Thanks V
Yes, if the vacuum to the regulator is restricted, it will alter how the regulator works.
__________________
Anything really new is invented only in one’s youth. Later, one becomes more experienced, more famous – and more stupid.” - Albert Einstein
JFP in PA is offline   Reply With Quote
Old 09-10-2019, 12:41 PM   #11
Vza
Registered User
 
Join Date: Oct 2018
Location: Nj
Posts: 31
I did the test and got 18.5 in/hg of vacuum. Seems thats correct considering thats what it measured right from the vacuum hose as well. So it seems there are no restrictions. No gas coming from FPR at idle with hose disconnected. Any other thoughts for the 1123 1125 codes. It seems only to come up if I accidentally get close to stalling the car w the clutch or I rev high briefly getting into gear. Although the code is still pending shortly after reset. V


Vza is offline   Reply With Quote
Old 09-10-2019, 04:52 PM   #12
Registered User
 
Join Date: Aug 2018
Location: Woodland Wa
Posts: 149
Quote:
Originally Posted by Vza View Post
I did the test and got 18.5 in/hg of vacuum. Seems thats correct considering thats what it measured right from the vacuum hose as well. So it seems there are no restrictions. No gas coming from FPR at idle with hose disconnected. Any other thoughts for the 1123 1125 codes. It seems only to come up if I accidentally get close to stalling the car w the clutch or I rev high briefly getting into gear. Although the code is still pending shortly after reset. V


Have you done an intake vacuum test????
If you get 18.5 in of vacuum that is within spec but on the low end.
I had a minor vacuum leak on my 2000S and still pulled 19.
If you have a vacuum leak it could contribute to your codes.
blue62 is offline   Reply With Quote
Old 09-11-2019, 10:59 AM   #13
Vza
Registered User
 
Join Date: Oct 2018
Location: Nj
Posts: 31
What is the spec for Vacuum?
Vza is offline   Reply With Quote
Old 09-11-2019, 11:11 AM   #14
Registered User
 
Join Date: Feb 2005
Location: It's a kind of magic.....
Posts: 5,123
Quote:
Originally Posted by Vza View Post
What is the spec for Vacuum?
0.4-0.6 Bar
__________________
Anything really new is invented only in one’s youth. Later, one becomes more experienced, more famous – and more stupid.” - Albert Einstein
JFP in PA is offline   Reply With Quote
Old 09-11-2019, 11:20 AM   #15
Vza
Registered User
 
Join Date: Oct 2018
Location: Nj
Posts: 31
So I'm at .63 Bar ....so I'm on the high side. Is that acceptable? V
Vza is offline   Reply With Quote
Old 09-11-2019, 11:23 AM   #16
Registered User
 
Join Date: Aug 2018
Location: Woodland Wa
Posts: 149
Quote:
Originally Posted by Vza View Post
What is the spec for Vacuum?
if your asking for the vacuum spec. at the intake it is 18-22 in/gh of vacuum preferably with a steady needle.
At engine idle

Last edited by blue62; 09-11-2019 at 11:30 AM.
blue62 is offline   Reply With Quote
Old 09-11-2019, 11:33 AM   #17
Vza
Registered User
 
Join Date: Oct 2018
Location: Nj
Posts: 31
Cool

Ok...well I have two specs going here !! 0.4-0.6 Bar and 18-22 in/hg I'm on the high side of 1 and low side of the other.

Last edited by Vza; 09-11-2019 at 11:36 AM.
Vza is offline   Reply With Quote
Old 09-11-2019, 11:47 AM   #18
Registered User
 
Join Date: Aug 2018
Location: Woodland Wa
Posts: 149
sorry not meaning to create confusion.
I would say your reading is fine
blue62 is offline   Reply With Quote
Old 09-11-2019, 11:58 AM   #19
Vza
Registered User
 
Join Date: Oct 2018
Location: Nj
Posts: 31
Thats fine thanks V
Vza is offline   Reply With Quote
Old 09-11-2019, 06:06 PM   #20
Vza
Registered User
 
Join Date: Oct 2018
Location: Nj
Posts: 31
I don't know maybe its a quirky thing with the codes. I drove at length before they showed up. No pending codes now... I guess I'll see what happens. My oil filler cap checks out good and I sprayed some carb cleaner around the small hoses coming off the vac tank,plenum hoses etc...no change in engine note.Thoughts?? V
Vza is offline   Reply With Quote
Reply


Thread Tools
Display Modes

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 On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 05:06 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page