I have a 1997 blazer 4dr 4x4, with 195k miles. I had the P0300 code, tried plugs and wires, to no avail. A little later, my coil pack blew out and I had to have it towed. The mechanic said he replaced the coil and noticed it still had a misfire. He changed the distributor and PCM, neither of which fixed the problem. Then he said maybe it was in the fuel injection and would cost hundreds to fix. I said I would just drive it, and I took it home. So I've been doing some research on the fuel injection and have a few questions. My misfire is only at idle and when I first hit the gas, then it smooths out and drives fine. I drive it every day to work and down the highway it is completely fine, except for it taking a while for the torque converter to lock up.

I understand this engine uses a fuel injection spider. My question is, should I try replacing this or should I just change the O rings to solve my problem. I'm not entirely sure what would be causing this. Any thoughts? Thanks.

 

It's possible that the FPR is slightly leaking causing a rich condition on a cylinder or two at idle. You can test your fuel pressure by using the procedure found in the Tech Article (DIY) section to see if that is a concern.