Tune up issues

[Oddbr13n]

Okay, so here we go, I started a tuneup on my 1997 5.9 2500 4x4

Before I started I had a misfire in cylinder 8, as I started my tune up, I noticed gunk on the spark plug for 8, I’ve also redone the distributor cap and made sure it has been wired correctly. It’s started up, and runs, however it feels as if it’s still misfiring , it doesn’t happen in park, just neutral and happens intermittently during acceleration. I’m scratching my head real hard right now I tightened down the throttle body, and confirmed the air intake is fully tightened and there are no leaks coming from there.

 

[Yeret]

How's the engine's oil consumption?

 

[Oddbr13n]

I don’t seem to be going through oil at all, will double check that this
Morning though

 

[Oddbr13n]

The misfire also jumped from 8 to 7 yesterday ?

 

[Yeret]

Leaking intake plenum will cause plenty of misfires even after you install fresh spark plugs. Ask me how I know, LOL. The engine will use a measurable amount of oil over a short time (mine used to use half a quart every 120 miles!). The engine will also likely develop spark knock under load (mine used to sound like a literal can of marbles in a tin can).

A good sign of oil consumption is gunk buildup on the spark plug electrode. Oil is very dirty when it burns and will promptly leave deposits pretty much everywhere.

Also, what spark plugs did you use?

 

[Steve brown]

when I tuned my 1996 5.9 the factory plugs were champion I replaced them with double platium plug drove it to work that week truck ran worse after the tune up put the champion plugs back in it ran fine