Was there ever a point where the 4.3's got the upgraded design from the factory? Also, is there any point in changing to the newer design if the old one isn't showing any signs of being bad? Thanks!

 

The 8th character of the VIN tells which system the vehicle came with originally.

1996 through 2002 is equipped with the "W" engine with CSFI, (Central Sequential Fuel Injection) 6 injectors centrally located in one housing inside the plenum with 6 "spider" lines, (one to each intake port), with a poppet valve in each one.

2003 through 2005 S&T body, (except Bravada) is equipped with the "X" engine with SMFI, (Sequential Multiport Fuel Injection) 6 injectors, one located at each intake port, and no poppet valves.

2001 was the last year that Bravada had the 4.3L "W" (CSFI) engine, and the injector upgrade is available for it. If the injector assembly develops problems, it's usually cheaper to do the upgrade than to replace individual components. The Bravada was never produced with the "X" engine. Starting in 2002 Bravada went to the 4.2L inline 6 cylinder engine.

 

Pardon the slight tangent to this thread .....


I am very vague in my understanding about the "spider" injection. I have a 98 4x4 4dr Blazer with the "W" engine. So I have the "bad" spider injection? Is the upgrade exactly the same as the no poppet assembly that is stock with 2003 through 2005 S&T body?

Is there a "primer" about the bad spider assy that is in my 98 4.3 engine?

Thanks!

 

Good question

The 98 did come with the poppet valves. There's a poppet valve located at the end of each "spider" line and it doubles as the nozzle for spraying fuel in a cone shaped pattern. It's not a "bad" set up, some of them never have a problem. It just depends on the quality of fuel used, and the way the vehicle is driven. Short "hot soaks", without giving the engine a chance to completely warm up, tends to varnish the nozzles. If the fuel does not have a good detergent "package", the poppets can gum up even quicker. When they get varnished up, the spray pattern gets deformed and causes driveability issues. The injector upgrade is identical to what comes from the factory in 2003 through 2005 "X" engines. The upgrade is "plug & play", no programming of the PCM is necessary. The "X" engines already have the injector upgrade, no EGR valve, and no secondary AIR system. http://ww2.justanswer.com/uploads/Bl...conversion.pdf

 

Attached is the Amazon Description. I just did this in my 2000 Jimmy. Besides this kit you need a Intake manifold gasket set.

 

X2 on the gasket, but you only need the upper: Buy Dorman - OE Solutions Dorman Only 615-182G at Advance Auto Parts

The Delphi injector kit comes with the, (necessary) bracket for the new injector housing. Some of the "off brands" do not supply it, $20 extra.