Evening gentleman. My first post here searching for some help. My Blazer driving me crazy. Here's the story.....Lost #5 injector about 700 miles ago and replaced it. Lost #3 about 700 miles after I replaced #5. So I said, hell with it, I'm just replacing all of the ones that are left now. Did that this morning and it still has a miss on 3. Been to Auto Zone twice now and it says misfire on 3. Changed the spark plug, ohmed out the wire and the injector just to be sure, all read within specs. Any ideas gentleman??? Thanks in advance folks. Happy 4th of July all.

 

You went the expensive way of replacing the injectors... For anyone else, if you are thinking of replacing more than one injector, just get the upgraded MFI kit for the 96+ engines.

Have you checked your cap/rotor? Hows the compression on #3 in relation to the rest of the cylinders? How does the plug look?

Beyond that, please provide some more details about your truck and search up on 'P0300'.

 

Im sorry, DUH. 2003 model. The reason I replaced only 1 at first was because the guy at Auto Zone told me it wan unusual for one to go out so soon, so thinking it was an anomoly, I just replaced the one. Got it on E Bay for $40, so I can't complain. Got one more for $40, and the other 4 for $60 each. Took the plenum back off and found #3 line was kinked. I moved 2 injectors around to straighten it out and put another one in it's place. Took great pains to ensure it didn't get kinked again, put it all back together, and drove about 10 miles with no check engine light or other problems. As soon as I pulled in the driveway and put it in park, the miss came back it seems. Surely the line didn't get another kink in it from engine heat perhaps. Sure ain't how I wanted to spend my weekend.

 

Still would have been cheaper in the long run to pay the $250-300 for the MFI kit (which is what yours came with stock) than to buy each of the injectors separately. But that's besides the point. That was more of an FYI for everyone else out there. Another reason to replace them all at once is that all of them have been in there for the same amount of time. The chances of creating an imbalance when replacing more than one injector (especially on the same bank) is increased.

If those lines kink once, it is very likely that they'll kink again.