Just replaced the Spider Injector, Fuel pump, and fuel filter on 2000 Blazer 4x4

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May 27, 2015 | 09:50 AM

#21

mickey_bigdaddy

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Quote:

Originally Posted by Captain Hook

"Fuel metering block" is the technical term for it. The 1996 through 2002 OEM S&T body have 6 mini fuel injectors inside. Each injector directs fuel through the "spider" lines to a poppet valve located at each intake port. 2003 through 2005, (and the upgrade) relocates the injectors to the intake ports, and eliminates the poppet valves.

If the OEM spider assembly poppet valves are clean, and the assembly has no other problems, you might notice a slight difference in performance & fuel mileage using the upgraded version. Usually the OEM is replaced due to a problem, that's when you notice a substantial difference when upgrading.

I have a 99 with the OEM spider assembly. Can I just take a 2003-2005 intake plenum with its upgraded fuel metering block and switch in with mine? Plug and play?

May 28, 2015 | 04:06 PM

#22

Captain Hook

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From: Belleville, Michigan

Mickey, the injector upgrade is plug & play, no relearn of any type is necessary. Don't need the plenum, just the injector assembly and mounting bracket.

May 29, 2015 | 06:53 PM

#23

tlamana

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Can you do the CPI to MPI conversion on a '94? I see the Delphi unit for '96 but I can't find anywhere that says you can do it for an earlier year.

May 29, 2015 | 07:40 PM

#24

Captain Hook

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Nope. 1995 and older have one injector that is "batch fired" simultaneously for all 6 cylinders. 1996 and newer have six injectors that are fired individually for each cylinder.

May 29, 2015 | 10:53 PM

#25

tlamana

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Quote:

Originally Posted by Captain Hook

Nope. 1995 and older have one injector that is "batch fired" simultaneously for all 6 cylinders. 1996 and newer have six injectors that are fired individually for each cylinder.

Right, that is the CPI. This is a video showing the conversion.

Last edited by tlamana; May 29, 2015 at 10:59 PM.

Jun 3, 2015 | 08:59 PM

#26

tlamana

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Still looking for an answer.

Jun 3, 2015 | 09:42 PM

#27

Captain Hook

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Quote:

Originally Posted by tlamana

Still looking for an answer.

The answer to your question in post #23, is in post #24.

Jun 3, 2015 | 09:44 PM

#28

tlamana

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Except in the video it was a cpi to mpi conversion from all to each so I don't get the difference.

Jun 3, 2015 | 10:14 PM

#29

Captain Hook

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From: Belleville, Michigan

1995 and older VIN "W" are CPI, (Central Port Injection). There is one fuel injector, and a poppet valve at each intake port. There is no upgrade for this system. The video is 1996 or newer which is CSFI, (Central Sequential Fuel Injection) also VIN "W". There are 6 fuel injectors in the metering block, with poppet valves at each of the intake ports. The upgrade to MPI, (Multi Port Injection) can be done on 1996 through 2002. It relocates the injectors to the intake ports and eliminates the poppet valves. 2003 through 2005 S&T body 4.3L originally came with MPI and the 8th character in the VIN is "X".