P0300 Code - Random Misfire ...Help please!

[M&MsZ71]

On my way home from work last night, I was driving on the highway and my truck threw a Service Engine Soon light. I went to check the codes today and it came up code P0300 misfire detected. The truck doesn't seem to be running any differently or have any noticeable problems just from driving it. But what should I check for this code right off the start? Any common problems that would throw this code in these trucks? Its my 1997 K1500 with the 5.7... Thanks for the help!

 

[1997chevydriver]

On my way home from work last night, I was driving on the highway and my truck threw a Service Engine Soon light. I went to check the codes today and it came up code P0300 misfire detected. The truck doesn't seem to be running any differently or have any noticeable problems just from driving it. But what should I check for this code right off the start? Any common problems that would throw this code in these trucks? Its my 1997 K1500 with the 5.7... Thanks for the help!

Could be dist cap, fuel pressure low?

Sent from somewhere in MN

 

[twomanymontes]

I just had a van in the shop that kept setting that code on decel. Plugs and wires were recently replaced [less than 200 miles], Ran perfectly fine but was counting misfires. I ran some GM top engine cleaner threw it and it stopped counting misfires.

 

[M&MsZ71]

What I think I am going to do is just do a full tune up. I am going to replace all the plugs, wires, dist cap, etc... and see where it goes from there. I am going to get the fuel pressure checked also.

 

[M&MsZ71]

I just had a van in the shop that kept setting that code on decel. Plugs and wires were recently replaced [less than 200 miles], Ran perfectly fine but was counting misfires. I ran some GM top engine cleaner threw it and it stopped counting misfires.

Could you get that GM top engine cleaner at just any auto store? And is it basically just like a seafoam kind of thing? Thanks

 

[twomanymontes]

We get it right from the Chevy dealer down the street. Never actually bought it myself, so I don't know what it costs. Just know it works! But Seafoam is probably the next closest chemical. But remember that stuff is nasty strong!!! BG has something simular as well.

 

[M&MsZ71]

Ok guys, so I took a few things apart and took some pics for opinions. These questions may sound dumb but I want to make sure I am getting the right parts that are needed first. First off... For the dist. cap and rotor, does the white powder looking trace on the inside of it indicate its bad? Is it corrosion maybe? And about the spark plugs, they are AC Delco plugs which I have heard last a long time. But they look like they arent in to great of shape? Opinions are greatly appreciated. I am just trying to figure out what the last owner replaced and didn't replace.

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[Yeti_Owner]

Ok guys, so I took a few things apart and took some pics for opinions. These questions may sound dumb but I want to make sure I am getting the right parts that are needed first. First off... For the dist. cap and rotor, does the white powder looking trace on the inside of it indicate its bad? Is it corrosion maybe? And about the spark plugs, they are AC Delco plugs which I have heard last a long time. But they look like they arent in to great of shape? Opinions are greatly appreciated. I am just trying to figure out what the last owner replaced and didn't replace.

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It all looks pretty good to me, honestly. The cap may be a little sketchy, I guess.

 

[twomanymontes]

You can see the burn mark on the side of the cap, that gray looking mark in the lower right corner. The rotor looks Ok, but since you will need to repalce the cap anyways, dropping another $5. isn't a big deal. The deposits on the plugs don't look bad, does not look like your burning oil.

 

[M&MsZ71]

You can see the burn mark on the side of the cap, that gray looking mark in the lower right corner. The rotor looks Ok, but since you will need to repalce the cap anyways, dropping another $5. isn't a big deal. The deposits on the plugs don't look bad, does not look like your burning oil.

Thank you! I appreciate it for pointing that out. I will be replacing the dist. cap then and like you said I might as well do the rotor too.