Blazer Forum Blazer Forum  
Chevy Blazer Forums
Chevrolet Blazer Forums
Chevrolet Blazer Blazer Forum   Classifieds   Photo Gallery   Search   Contact BF   Sponsors
  Blazer News   Member List   Forum FAQ   Timeslips   Recalls   TSBs   Calendars   Register   Login  

results of my fuel pressure test

  Printable Version
Blazer Forum >> Mechanical & Maintenance >> General Tech Help >> 2nd Gen (1995-2005) Tech >> results of my fuel pressure test Page: [1]
Login
Message << Older Topic   Newer Topic >>
results of my fuel pressure test - 2/9/2008 11:21:59 AM   
zombiewoof

 

Posts: 55
Joined: 1/21/2008
Status: offline
I tested my fuel pressure because every once in a while I can smell fuel in the cab, I also recently blew a head gasket and had alot of carbon build up in the engine, this is  on  my 95 blazer

   The pressure with pump running (engine off) was 62 psi and it droppen down to 58 psi as soon as the pump stopped, it held 58ps for 3 min,

Should I be concerned about the slight leak down?

time elapsed (minits)     pressure
  4     57
  5     56
  6     56
  7     56
  8     55.5
  9     55
10     55
11     55
12     55
13     55
14     55
15     54
16     54
17     54
18     54
19     54
20     53.5
25     52
30     52
35     50
40     50
50     49
60     49
 

Thanks in advance for your input....

BTW My nickname (Zombiewoof)  comes from the title of a Frank Zappa song I like


_____________________________

1995 Bazer 4 dr 4X4 Rockport (mine)

1996 Blazer 4 dr 4X4 Rockport (wifes)

1963 Impala , summer time hobby
Post #: 1
RE: results of my fuel pressure test - 2/9/2008 4:26:53 PM   
c0a8l0v6i8n9


Posts: 179
Joined: 1/6/2008
Status: offline
c0a8l0v6i8n9's photo gallery
The pressure shouldnt drop more then 3-5 PSI

_____________________________

1994 4 Door S10 Blazer, 4.3 VIN "W", 95,xxx miles, Xenon Lights, Driving Lights, Pioneer DEH-3900MP, Infinity Kappa 462.7CFP, Kenwood KFC-1682ie.

(in reply to zombiewoof)
Post #: 2
RE: results of my fuel pressure test - 2/9/2008 6:12:01 PM   
swartlkk


Posts: 14530
Joined: 5/1/2005
From: Waterloo, NY
Status: online
swartlkk's photo gallery
A slow leak down like this could be caused by the 'nut kit' (internal lines), the fuel pressure regulator, or the check valve in the fuel pump itself.  It doesn't sound like an excessive leak...

_____________________________

Kyle-

04 Rainier
My Restoration Projects
Please Do Not PM for Tech Help

(in reply to c0a8l0v6i8n9)
Post #: 3
RE: results of my fuel pressure test - 2/9/2008 8:27:49 PM   
zombiewoof

 

Posts: 55
Joined: 1/21/2008
Status: offline
the pump was new about a year ago...although I do have the dancing fuel guage syndrome, I noticed a verry slight washing on the regulator side when I had the upper intake off,,,I think Ill just go ahead and replace it,,,Its funny how I had to spend 70$ to diagnose a 40$ part...hehe..oh well at least i can segrigate a fuel problem when needed...thanks for the replies

PS Kyle...the pressure tester I made at work would have been good...I found this big 100psi liquid filled sour gas gage...had a bleeder valve set up with a drain hose, and was using a pressure line from a grease gun...it looked like a store bought unit...But I couldnt find anything to conect to the schrader valve...hehe people looked at me like i had rocks in my head when I was trying to explain what i needed it all for (the conector)...



< Message edited by zombiewoof -- 2/9/2008 8:46:08 PM >


_____________________________

1995 Bazer 4 dr 4X4 Rockport (mine)

1996 Blazer 4 dr 4X4 Rockport (wifes)

1963 Impala , summer time hobby

(in reply to zombiewoof)
Post #: 4
RE: results of my fuel pressure test - 2/9/2008 8:54:32 PM   
Psychropod


Posts: 338
Joined: 5/23/2007
From: Baltimore, MD
Status: offline
Psychropod's photo gallery
This is so great that somebody posted this, because my '96 has also been having a fuel pressure problem lately.  I just bought a fuel filter today and plan to get a regulator tomorrow, once I find a parts store that actually has one in stock. 

I don't have a gauge to test it with, but I figure it can't hurt to replace both anyway. The filter hasn't been replaced during the three years we've had the truck, and the regulator has probably never been replaced ever.

The problem I'm having is that it never starts right up.  It takes at least 2-3 attempts.  The starter sounds fine, and I know it's not spark, because the plugs, wires, and distributor are all new and working fine.  Hopefully replacing the filter and regulator will resolve the problem, 'cause if not, it will make me think the pump itself is dying.

Anybody else have any thoughts on this?


_____________________________

Raphael

(in reply to zombiewoof)
Post #: 5
RE: results of my fuel pressure test - 2/9/2008 9:01:09 PM   
zombiewoof

 

Posts: 55
Joined: 1/21/2008
Status: offline
I think your in kind of the same situation I was in...as in being..your not really going to know whats going on with it unless you get the guage on it....I hope you can solve your problem with the regulator and not have to get a new pump...But I did read a previous post that said the initial higher pressure is needed for starting...

_____________________________

1995 Bazer 4 dr 4X4 Rockport (mine)

1996 Blazer 4 dr 4X4 Rockport (wifes)

1963 Impala , summer time hobby

(in reply to Psychropod)
Post #: 6
RE: results of my fuel pressure test - 2/9/2008 9:09:14 PM   
Psychropod


Posts: 338
Joined: 5/23/2007
From: Baltimore, MD
Status: offline
Psychropod's photo gallery
Okay, because it's good to know that I'm on the right track.  I ran a search and found another really helpful thread about that issue here:  Click Clicky

Thanks!


< Message edited by Psychropod -- 2/9/2008 9:20:25 PM >


_____________________________

Raphael

(in reply to zombiewoof)
Post #: 7
RE: results of my fuel pressure test - 2/11/2008 8:00:57 AM   
zombiewoof

 

Posts: 55
Joined: 1/21/2008
Status: offline
On my 95 blazer if I want to replace the fuel pressure regulator  (CMFI system) It apears at though I would have to replace the whole CMFI assembly....is this correct? Because Rock auto lists a pressure regulator but my manual says the regulator is part of the whole assembly....In wich case a pressure regulator is gonna run me somewhere in the neighborhood of 400 - 450 bucks....OUCH!!  

_____________________________

1995 Bazer 4 dr 4X4 Rockport (mine)

1996 Blazer 4 dr 4X4 Rockport (wifes)

1963 Impala , summer time hobby

(in reply to Psychropod)
Post #: 8
RE: results of my fuel pressure test - 2/11/2008 8:07:12 AM   
swartlkk


Posts: 14530
Joined: 5/1/2005
From: Waterloo, NY
Status: online
swartlkk's photo gallery
It is replacable, however it isn't an easy job.  The Lindertech repair kit replaces the stock regulator on the CPI with one used on the SCFI (96+) spiders.  They have complete instructions for the change over as well.  It will require removal of the spider which I would recommend that you replace the 'nut kit' (internal lines) as well.

You might want to check out the whole kit which includes a refurbished CPI spider with updated FPR, the 'nut kit', an upper plenum gasket, and a screened EGR gasket for $300.  I have never heard anyone say anything bad about the parts received from Lindertech.


< Message edited by swartlkk -- 2/11/2008 8:12:49 AM >


_____________________________

Kyle-

04 Rainier
My Restoration Projects
Please Do Not PM for Tech Help

(in reply to zombiewoof)
Post #: 9
RE: results of my fuel pressure test - 2/11/2008 8:33:40 AM   
zombiewoof

 

Posts: 55
Joined: 1/21/2008
Status: offline
Thanks again Kyle, I just E-mailed them to see if they would ship the kit to Canada,..Before I decide to go this rout I suppose I should test to see if my leakdown is from the CPI unit or the pump damper, The only reason Im looking into this is that I noticed a small spot of washing  in the upper intake when I was replacing my head gaskets...it was near the rear corner by the rear passenger side, I have had a slight missfire(more like a small stumble...not really noticable and never effected the idle rpms) for a long time also...I also had some oil in the upper --- I think that was form a bad pcv..
  The upper intake is really in no way washed...its nice and dirty as you would expect it to be,,,all except for a small spot about 1/2 the size of a dime...Im wondering if the oil (real small amount) could have caused that clean spot??

  I wish I had of taken a picture of it to post....But Thanks again for the info

< Message edited by zombiewoof -- 2/11/2008 8:41:38 AM >


_____________________________

1995 Bazer 4 dr 4X4 Rockport (mine)

1996 Blazer 4 dr 4X4 Rockport (wifes)

1963 Impala , summer time hobby

(in reply to swartlkk)
Post #: 10
Login OR Register now to post a reply to this forum topic.
Page:   [1]

 
Blazer >> Mechanical & Maintenance >> General Tech Help >> 2nd Gen (1995-2005) Tech
Jump to:



Featured Sponsors
Advertising Info

Top 10 Posters
swartlkk14530
drperry3901
hanr33482
chevy lover3411
m00nwater3269
eurogoldls3121
paddle_grl2944
hillbillyino2885
wolfpack2844
xblazer012659

New Vendors
AMSOIL - Performance Oil Technology

Add Blazer Forum to your favorites Contact Us | Advertising | Partners | About Us | Archive | Links | Link To Us | Legal | Privacy Policy | © Blazer Forum

Blazer Forum .com is not affiliated with or endorsed by Chevrolet Motors Division or General Motors.