2002 Chevy Blazer eng boogs on acell

Tiny
RICHARD FERGUSON
  • MEMBER
  • 2002 CHEVROLET BLAZER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 60,000 MILES
New vehicle to me. I put new cat @ muffler, plugs-wires-cap @ roter, fuel filter, cleaned throttle body, and I was told it had a new fuel pump, it looks fairly new, the filter was really pluged, and vehicle performed the same. Fuel pressure on rail is 52 psi with eng running-55psi with vac applied by hitting throttle, I put gague on filter with eng off, cycled key and rt was 58psi at best. Is fuel pressure ok? I got 3 02 codes-po131-po137-po151-the 02's look like the switching is good until you hard acell, then all 3 02's go to real low readings and stay there, fuel pump? I do not know what it should be. HELP. Thank's.
Sunday, August 1st, 2010 AT 7:14 PM

7 Replies

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Hi richard ferguson, Welcome to 2carpros and TY for the donation

Your fuel pressure should be 60-66psi re-check the fuel pressure again-could be a problem with the fuel pressure regulator leaking inside-if its a CPI spider injection-confirm injection system

4.3L engine

Astro, Safari, Sierra & Silverado 55-62 psi (379.2-427.5)

Blazer, Express, Jimmy Canadian, Savana, Sonoma & S10 60-66psi (413.7-455.1)
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Sunday, August 1st, 2010 AT 8:01 PM
Tiny
RICHARD FERGUSON
  • MEMBER
  • 4 POSTS
Putting a fuel pressure gague on the out put side of the filter should show a larger amount of PSI, or so I would think, because it is befor the regulator, straight from the pump should be higher, or can the regulator make it higher? Pump to filter to gague is not regulated, what's your thought?
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Sunday, August 1st, 2010 AT 8:26 PM
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
The regulator will make it higher if the return line is clogged.

The pressure should be the same before and after the fuel filter, if lower at after its clogged. If you open the upper plenum you'will know if the FPR leaking or the nut kit-investigate
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Sunday, August 1st, 2010 AT 8:39 PM
Tiny
RICHARD FERGUSON
  • MEMBER
  • 4 POSTS
I disconeceted the line from the nfilter and put a gague, no fuel was allowed to go to the eng, pump directly to gague and no ferther.58PSI. Shouldn't it go more than spec's? I'm confused.
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Sunday, August 1st, 2010 AT 9:04 PM
Tiny
RASMATAZ
  • MECHANIC
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Check the fuel pressure while engine is idling remove the vacuum hose from the FPR the pressure should increase 8 to 10psi if not the fuel pump is weak or the pick-up sock/strainer in the tank is clogged
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Sunday, August 1st, 2010 AT 9:26 PM
Tiny
RICHARD FERGUSON
  • MEMBER
  • 4 POSTS
So the lack of pressure orignates at the pump or sock, this must eliminate the regulator, correct?
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Sunday, August 1st, 2010 AT 9:52 PM
Tiny
RASMATAZ
  • MECHANIC
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Possible causes include a worn fuel pump, low voltage at the pump, or inlet sock in the tank, and obstructed fuel line.
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Monday, August 2nd, 2010 AT 12:38 AM

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