MISFIRE - help, please!

[HoustonHelix]

Scanner indicates a "Misfire on Cyl #6".

I tried to isolate the problem by switching with Cyl#5 the sparkplug, then sparkplug wire, then injector. Each time I would do a switch, I would reset the Engine Service light, wait for it to come on then do a reading. Each time the light would come on it would indicate the same message not showing it the problem jumping to Cyl #5.

Since I have determined that the plug, wire, and injector is good in Cyl #6, yet continue to get a misfire, could someone advice on what I else I need to check?

[J-Ri]

Originally Posted by HoustonHelix

Scanner indicates a "Misfire on Cyl #6".

I tried to isolate the problem by switching with Cyl#5 the sparkplug, then sparkplug wire, then injector. Each time I would do a switch, I would reset the Engine Service light, wait for it to come on then do a reading. Each time the light would come on it would indicate the same message not showing it the problem jumping to Cyl #5.

Since I have determined that the plug, wire, and injector is good in Cyl #6, yet continue to get a misfire, could someone advice on what I else I need to check?

How did the spark plug look? You didn't say what engine it has, and I can't remember what year they went to the 4.8/5.3/6.0. If you have the 4.3/5.0/5.7, check the coolant level. If it's low, I'd guess you probably have a lower intake gasket leaking. Those engines are known for that.

[maxwedge]

And the vehicle/engine is?

[wrightz28]

Dunno max,

Seems to be mifiring in a C/K, a Camaro, a 3000 GT, What's the deal Houston?

[silicon212]

Could be mechanical, as well. Blue Bowtie has a great picture in the Nonspecific forum of a car that was driven in with a P0300 (random misfire) and when he pulled one of the valve covers off, he found the rocker arms for two valves pulled out of the head. Each rocker was for one valve on one cylinder, and he said there was another rocker on the other bank the same way - in effect, the engine had been turned into a 3-banger. It looked to be one of those 3100 series engines.

[67chevypickup]

that guy made a good point i didnt think of but how hard do you drive this thing? if your trying to set land speed records thats about the only way a stud will pull out. What are we talkin for milage here and does it run an individual coil system?