When pulling hills or sometimes times early in the morning, my '95 S10 Blazer Eng Code W with CPI check engine light comes on and flashes then goes away. Not sure what this might be, it differenly seems to have a miss when the light is flashing, just wondering if the light is not staying on is it really throwing a code.

Any help always appreciated. thanks

 

A FLASHING check engine light means the PCM is detecting a Catalyst DAMAGING missfire. You have a bad miss my friend....if it only happens under load.....check or replace your plugs and wires first.

 

Thank you very much, I'll get dirty Sat. morning then.

It diffently feels like a miss. The plug on the driver side closest to the fire wall is a pain in the rump roast for sure.

 

Nah it's the one in the middle of the driver's side (#3).

 

One of your plugs may be loose. Does it only do it in the morning when it is not at full operating temp? Then the light stops flashing and the SES light goes out? When the engine gets hot the heads expand and your loose plug isn't loose anymore. I had to tighten my drivers side rear plug the other morning. I could hear it though when I listened inside the drivers wheel well. Mine did the same as yours for 2 mornings in a row. I'm going to check them all this weekend.