Great info. Thanks for the VIN identification and the simple explanation.
So teh Injectors now snap(?) into the Poppet holes at the intake.
My guess is you get a much better Spray pattern directing from the Injector on the new style.
Thanks

Now that I got this info I can ask this question better...Did GM ever make an 'X' engine blazer? or did the Injector setup come after the S10's left the GM line?

 

Sooo....which unit to get for my 96 Blazer??

- Delphi unit pn FJ10565 - 191 at Amazon
- GM (AC Delco?) unit pn 12568332 - 202 at Partszone Online, 262 at GM Parts Direct
- GM (AC Delco?) unit pn 19210688 - 246 at Partszone Online, 270 at GM Parts Direct

Any know what the difference is between Delphi and GM units? What about between the two GM units?

Just want to get the right one!

 

I believe the 2003-2005 came with the MPFI
96+ can take advantage of this. More reliable system that does not have the problem of sticking poppets.

Good deal:

 

ACDELCO Part # 2173028 {#89060439} Includes Instructions for Conversion from Poppet-Style Invectors
INJECTOR KIT,CENTRAL SEQ M/PORT FUEL

I also see this one for the '96 at ROCKAUTO.COM

 

The poppet nozzles snap into the intake ports on all W engines and spray directly from the nozzle. The new injector nozzles snap into the same holes that the poppets used to. Spray pattern is virtually the same on both systems. 1995 (OBDI) and older W engines with CMFI, (Central Multiport Fuel Injection) have one injector that is batch fired, (delivers fuel to all nozzles with each injector pulse) so the fuel is constantly moving through the injector lines and poppet nozzles. The injectors on 1996 and newer W engines with CSFI, (Central Sequential Fuel Injection) are sequentially fired with the ignition firing order. As a result, the fuel moves much more slowly through the injector lines and has a tendency to varnish up the nozzles under certain conditions. Relocating the injectors to the intake ports exposes them to higher temperatures and reduces the tendency of forming varnish in the nozzle. The upgrade technically changes the system to a SMFI, (Sequential Multiport Fuel Injection) system. It just doesn't get any better than this, unless you go to direct injection.

GM used the X engine in S&T body, (Blazer, Jimmy etc) G body, (full size van) M&L, (Astro Safari) and full size pick ups starting in certain vehicle platforms in 2001, I think 2002 & newer, all platforms had the X engine, (not 100% certain though).

Delphi # FJ10565
AC Delco # 217-3028

 

My '95 S10 Blazer might need spider injector but don't know yet until I do the test this weekend. I was wonder if Reman is a good brand or not?

 

CSFI was used on late 1995 models. If your 1995 has CMFI, this upgrade does not apply to your engine. Stay away from remanufactured units. https://blazerforum.com/forum/2nd-ge...95/#post524656

 

Ok so how can I know if my is CMFI or not?

 

So if a CSFI is operating fine with a nice spray pattern how does the SMFI seem to get you better mileage and smoother running?

 

This is CMFI:




This is CSFI:




Tony: By eliminating the poppets and relocating the injector to the port, there's one less thing to restrict the fuel flow.