2001 Silverado Random Missfire

Check Spark plugs, Do a power balance test. May be something mechanical as well (compression test may be necessary)

-Karl

[quote=”ToyotaKarl” post=157216]Check Spark plugs, Do a power balance test. May be something mechanical as well (compression test may be necessary)

-Karl[/quote]

P0300 would be a random misfire, hence not isolated to a single cylinder. Unless the entire engine is low on compression, I would doubt it’s mechanical.

Oddly enough, the wrong torque converter can cause this too(I speak from experience from a high stall converter on a GM truck), if a much smaller converter with less rotating mass, of course this results in a false code.

I’m inclined to say this is a fuel delivery issue
The engine should be fuel injected and not TBI, therefore fuel pump, filter or regulator may be suspect. Of course, this may or may not cause a lean code.

Loss of engine compression to the point where it’s misfiring like this would likely result in a rich code…inclined to say fuel system issue.
Wondering where he got the new/used engine from? That would help establish what we could be dealing with.
It’s late, no idea why I’m still up haha.

[quote=”gmule” post=157246]That engine uses the crank sensor to detect misfires so it won’t call out the individual cylinder that is misfiring.
With that being said that engine uses an injector unit with 6 injectors in a central location under the upper intake manifold. From the injector bank there are runner lines to each cylinder. The nozzles at the end of the runners have a tendency to plug up and the spray volume or spray pattern is disrupted causing a misfire. Sometimes you can clean them up with some fuel injector cleaner. If you are sure the ignition system is not the problem run a can of BG44k through the tank and see if that clears it up.

Another issue with these engines is that the distributor gear will wear out causing the distributor to be a little sloppy causing a misfire.[/quote]

That’s right, the V8s switched design..what I was thinking of. The 4.3, yes that’s right. Was too tired last night to think clearly lol.

[quote=”Chevyman21″ post=157249][quote=”gmule” post=157246]That engine uses the crank sensor to detect misfires so it won’t call out the individual cylinder that is misfiring.
With that being said that engine uses an injector unit with 6 injectors in a central location under the upper intake manifold. From the injector bank there are runner lines to each cylinder. The nozzles at the end of the runners have a tendency to plug up and the spray volume or spray pattern is disrupted causing a misfire. Sometimes you can clean them up with some fuel injector cleaner. If you are sure the ignition system is not the problem run a can of BG44k through the tank and see if that clears it up.

Another issue with these engines is that the distributor gear will wear out causing the distributor to be a little sloppy causing a misfire.[/quote]

That’s right, the V8s switched design..what I was thinking of. The 4.3, yes that’s right. Was too tired last night to think clearly lol.[/quote]

It is hard to keep up with all the mid year updates and changes v6 vs v8. Add in that all of the manufactures do this and it is any wonder we can get the right parts let alone fix them