I have a 1998 Blazer, VIN W, I have a P0300 and P0144. I?ve replaced the plugs, wires, distributor, and coil, and replaced the fuel filter. I tested the fuel pressure and the fuel pressure is good. It misses at idle on all cylinders. Any ideas? I also have P0466 but that shouldn?t be related at all, correct me if I?m wrong.

 

Do you have a scanner that will monitor live engine data? MAF, O2 sensors, fuel trim? If so I will give further instructions. If not, you're going to need one. For 1998 Blazer I recommend Car Diagnostic Pro (Android) along with a Bluetooth OBD2 adapter.

 

My girlfriend?s dad has one, he plugged it in and said the misfires were on all cylinders, random, at idle, and all my numbers on the sensors and stuff were good. He suggested checking the idle air control valve.

 

I'm sorry but I can't help you if you're not paying attention to what I say. Better to do what your girlfriend's dad says. Time to bond with him!

Best wishes