i have a 2001 bazer 2wd 4.3. and was wondering what type of injectores i have. One mech told me i have what is called a spider system. One other told me thats not true i have a different system? who is correct?

 

Technically it is still the spider system. You're '01 utilizes the CSFI (central sequential fuel injection) with 6 individual injectors arranged in a centrally located injector pack. From there, 6 lines run to the individual ports, each line having a poppet injector on the end to spray the fuel at the intake valve. Prior to CSFI, CPI was the main method of fuel injection. CPI (central port injection) was a batch fire injection system where all cylinders would get a pulse of fuel at the same time instead of the sequential firing (only when the cylinder in question had the intake valve open) of the CSFI.

 

Do all blazers since 01 have the CSFI? I would imagine they do.

 

Any S-10 Blazer from '96 to current with the 4.3L came with CSFI

 

Cool, thanks a lot.

 

But I think that GM/Chevrolet made a change from poppet valves to pure injectors in '02-'04 using the same "Spider setup". I believe there is a TSB on failed poppet valves and replacing them with a new "Spider" that contains MultiTech Injectors on each end. I found that TSB surfing on another site and right now I am not on that computer so I don't have the link. But I do remember that if people with the poppet valve CSFI can't get the valve repaired then the service department should tell the customer that there is another option...

 

It does look like they changed the injector in 2003-04, but the fuel metering body did not change. This is per GMPartsDirect.com listing for fuel injectors. Weird thing is that the fuel injector for the '03-'04 is also cross referenced with a 1999-2003 GMC Sonoma... I don't know how far to trust that information... Especially considering that they still have pictures of the old CPI intake manifold up for their parts explosions...

If the metering bodies did not change, then I doubt that the poppet changed to an electronic injector at the port. That would require so MANY changes that it wouldn't be backwards compatible.

 

I downloaded a copy of the document to my computer in MSWord and copied the text below from the replacement section for V-6 Engines ....GM made these to directly replace the poppet valves in the lower intake manifold... Lindertech also sells a similar unit through their website also... I think it sells for around $300+ for the unit.

If you want to look it up it lists Document ID#: 1234172 at the top...

[hr]Rough Idle After Start, And/Or A Service Engine Soon (SES) Light (Unstick And Clean Central Sequential Fuel Injection (CSFI) Poppet Valves or Convert to MFI) #00-06-04-003B - (Jan 30, 2003)

Important: Cleaning the CSFI injectors is the preferred repair. The CSFI unit should not be replaced until cleaning has been attempted. If the vehicle should return for the same repair, then the CSFI unit can be replaced with a MFI unit. If the vehicle is out of warranty, the customer should be given the option of which fix to pursue.

V6 Engines
1. Remove Upper Intake Manifold plenum and SFI Fuel Meter Body according to Service Manual Procedures.

2. Remove the Fuel Meter Body bracket and discard. Install the new bracket as shown in Figure 1.

3. Position Fuel Tubes of MFI Fuel Meter Body as shown in Figure 2. Tubes must be oriented away from the fuel pressure regulator end of the fuel meter body.

Notice: The number 3 Fuel Tube must be positioned behind the number 1 Fuel Tube to eliminate interference with the Upper Intake Manifold plenum when installed.

4. Insert the MFI Fuel Meter Body into the Fuel Meter Body Bracket on the Lower Intake Manifold being careful not to bind the Fuel Tubes. Make sure that the number three Fuel Tube is routed in behind number 1 and 5 Fuel Tubes as shown in Figure 2. Push down firmly on the fuel meter body locking it into the bracket.

Notice: Use caution when inserting injectors into lower intake manifold to be sure the correct injector is being placed into the correct hole. Injectors should not be removed once they have been installed. Removal of injectors from the intake manifold may cause damage to the retaining lugs on the injector.

Important: The Injector holes are numbered on the Lower Intake Manifold. The injectors are numbered on the side of the Fuel Meter Body.

5. Insert the number 3 injector into the correct Injector hole in the Lower Intake Manifold first. Install the number 5 injector next and then number 1. This sequence must be followed correctly to prevent interference of the Fuel Tubes. Injectors 2, 4, and 6 are then installed.

6. Insure that the electrical connectors of the injectors are positioned so that they do not interfere with each other and are pointing towards the center of the Intake Manifold. If necessary, rotate the electrical connectors inboard.

Notice: Lack of lubrication will make installation of the Upper Intake Manifold plenum difficult and may cause damage to the O-ring.

7. Lubricate the Fuel Meter Body Upper Manifold O-ring (orange in color) with clean engine oil.

8. Inspect the Upper Intake Manifold plenum gasket and replace if necessary. Reinstall the Upper Intake Manifold plenum following the procedures outlined in the Service Manual.

Important: Lubricate the Fuel Inlet and Return Lines with clean engine oil before inserting them into the Fuel Meter Body.
Make sure that the Fuel Line Retaining Bracket is properly oriented with the tabs down.

Most of the information before this text is the procedure on how to clean the poppet valves....etc.

 

Ok, yup, did find it. Didn't realize that was even an option. I guess that's what I'll be doing when I have problems. I'll just buy the injectors though because the meter body is the same between the two. The lines have the wires for the injectors on them and they just plug up into the meter body just like the injectors in the CSFI did.

BTW, here are the two pictures you were missing:

[IMG]local://upfiles/667/AC33A6B9562B4BFDAD595CAA33F0909E.gif[/IMG]

[IMG]local://upfiles/667/FA8993BC57B042B583CDD71FA3491CD2.gif[/IMG]

 

Also, here's the PNs for the CSFI to MFI conversion:
MFI Assembly - 12568332 - $147 from GMPD.com $295 GM List
V-6 Bracket - 88894355 - $18 from GMPD.com $31 GM List - don't think this is necessary to change, but it is recommended in the TSB
V-6 Seal Kit - 17113215 - $20 from GMPD.com $34 GM List - this is the intake o-ring gasket

*EDIT* - Oh yeah, and scrap the idea of just replacing the injectors individually... The Assembly (with 6 injectors) is cheaper by far than buying 6 injectors separately.