While inventing a completely "Off-The-Vehicle" Fuel Injector Cleaning Apparatus I called
"The FrankInjector Machine" as '60dgrzbelow0' on another Forum (Google it for the many images online) I learned the procedures of EFI Disassembly, Ultrasonic Cleaning while Activating the Pintels (Pintles) and then Pressure Cleaning and Fluid Balancing them all at 3 BAR (43.5 PSI) on both the GM Multec-I and Multec-II Style Sets of EFIS:
The EZ part of this work was performing the R&R of the Filter Baskets and "O" Rings on both kinds of EFIs...
You can do that part by simply (and carefully) Screwing in a Regular Sheet Metal Screw Into the Brass Ferrule at the mouths of the EFIs and pulling out the Old Basket Screens with a Pair of Pliers.
The Hard Part was later finding out that the Problems with most of the "Non-Performers" involved Damaged and/or Weak Coils as being the more significant issue. Within the last few years... The Chinese have copied and produced an Excellent Mimic of the Original $10,000.00
ASNU EFI Pressure Cleaning and Fluid Balancing System for only around $500.00. If you were intent on doing a whole array of EFI Cleanings...it might be worth investing in one.
The Price and Availability of the EFI Sets of (6) or more EFIs that have been re-conditioned Professionally on
ASNU Machines is Low enough to warrant skipping the procedure you are about to attempt. Furthermore... The Basket Screens you have in that Kit look like they were sold for the GM 350 Engines using the Original Brown PTFE "O" Rings and Shorter Baskets meant for the Multech-I Style of EFIs vs. the BLUE "O" Rings meant for the Multech-II Series ...so you WILL be able to tap them into the mouths of the Multech-II EFIs... but they may NOT perform adequately afterwards due to a Reduction in the Flow of Gasoline through them:
I will be the LAST Person to EVER discourage anyone from wanting to do Exploratory Automotive Repairs... But if your intent is NOT to Experiment but to get your Trailblazer or Envoy back on the Road ASAP... Check on Amazon and eBay for these Re-Conditioned sets of EFIs available at around $100.00. Best of Luck!