I have a 02 blazer with a 4.3 it has a misfire on #1 cyl, I need to change the injector on that cyl. I was wondering how hard it is to do.

 

Do a search for spyder assembly removal or play with the wording of the search. You don't have "A" injector, it's what's called a spyder assembly. Basically one injector that feeds 6 tubes with electric poppet valves at the end of each tube. They are what inject fuel into the cylinders.
How do you know for sure the misfire is because of the injector? Read any DTC's in the PCM?

Search around I'm sure you'll find your answer & probably more questions that need to be answered or figured out before removing the manifold to replace the spyder.

 

Lmao, you better hope its not the injector.

 

If it's a misfire it could be a number of things...
It might be the spark plugs or wires, it could also be a vacuum leak which is what cause my misfire. What makes you so sure it's the injector?

 

dude i dis searches for spider injector replacement and did it in the street 1 2 3. it took a few hours and painted my upper intake manifold and plastic intake body orange, had a few smokes, stared at a few chix... and done.. easy... trust me it looks scaries then it truely is

all it is is undo this hose unbolt that and done.. get the ac delco or delphi spider kit and new gaskets... also engine primer and paint.. looks bad ***. need a lil grease cause when u put it back together the plannum will be a lil tough.. ull also need crows foot... and a few beers.

 

I rebuilt, or really just cleaned, my spider assembly. It was scary, but it still works. Remove two nuts and the plate on the bottom of it, and they press out. It takes a LOT of force, and it's mostly plastic. But with a ground down screwdriver, it wasn't the hardest thing I've done. It will just be expensive if you break it!

Once opened, there was some debris to clean off the filter screens. This is also where the fuel pressure regulator is, has another filter screen that gathered junk.

I got into it due to the code "Random or Multiple Cylinder Misfire", didn't seem to help, but glad I did it after seeing the screens. Turned out to be distributor related on that code.

 

Fixing the problem isn't an issue if you can turn a wrench, its the price of the pos.