I'm not sure what injector setup I have. The truck is a '96 4.3 Blazer and O'Reilly auto is asking just shy of $400 for a replacement injector setup. The dealership told me they can set me up with parts to fix my ills for $175.00 (he said it's the injector poppet assy)
This price seems backwards to me..... What gives?

The truck is running on 5 cylinders. A couple of months ago it was just in the morning when it was cold and would fix after 20 miles or so, now it's all the time. I tried Techron and SeaFoam.
Auto Zone reads a "#1 misfire" and rich O2 sensor (related) code. The plug is white to light beige and never wet upon checking, all electrics have been replaced and until today there has been no backfire while forcing acceleration. Today I got a rapid backfire (I think through the intake) as I stomped the gas to avoid a wreck. The rest of the 20 mile drive is on a sluggish 5 cylinders and a flashing SES light. Sometimes the 6th cylinder will toy with me and kick in and out for a few miles or all the way home.

I have replaced all electrical and checked all vacuum in the system. My AC blows out of the vents at cruise but out of the defrost vents upon hard acceleration but I can't find a vacuum leak. I need to find the reason the fuel is lean to #1.
Any ideas?

 

What are the part #'s the dealership and O'Reillys' giving you ? Be sure the are on the same page. If you remove the injectors, Replace ther "O" ring that is on each vavle. (injector.)


Could be a bad 02 sensor. I would compression test that cylinder too. Heck, check all of them. A Chiltons or Haynes will show the compression tolerances. Good luck.

 

PhatKat:

The Dealers now have two versions of the "spider" for the 4.3L CSFI engine, in the 2003 model they replaced the tempermental poppet valves with a full Lt1 style fuel injector setup. Instead of the poppet valves they use the same Multitech injectors used on the full size v-8's for camaros since the 4.3 uses some of the same parts for a 350ci v-8. If your truck was still under factory waranty they would use that unit to replace a defective poppet valve spider. It costs about 350+ depending who the source is. So the older poppet valve units may have been price reduced at the dealer to sell out of the remaining on the shelf parts.

 

We first need to know what he has (CPI or SCFI) as some early '96 models came with the CPI motor. If he has SCFI, then I would definitely recommend buying the MFI manifold. The only real difference between the SCFI spyder and the MFI spyder is that the MFI spider moves the injectors from the main body out to where the poppet valves were located. It is a direct replacement.

PhatKat, does your engine have the throttle body facing up (SCFI - 1st pic) or forward (CPI - 2nd pic):

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