This is a copy and paste I really don't know if our trucks have this component..

Definition: The EGR valve is the main emissions control component in the exhaust gas recirculation system. The valve is located on the intake manifold, and opens a small passageway between the exhaust and intake manifold to allow a metered amount of exhaust to flow back into the engine. This reduces combustion temperatures and helps control the formation of oxides of nitrogen. The EGR valve is opened by the application of vacuum to its control diaphragm. Some also require a certain amount of exhaust back pressure before they'll open. On newer vehicles, the valve is electronic and uses one or more solenoids or a small stepper motor. The valve should remain closed while the engine is cold and at idle. It should only open once the engine has warmed up and is running at part-throttle. If the valve sticks shut (or is disconnected), NOX emissions will soar and detonation will often result (See Detonation and Spark Knock). If it sticks in the open position or fails to close all the way, it acts like a vacuum leak resulting in a rough idle, hesitation and possible stalling.

 

[QUOTE=2OOOSVT] NGK TR6IX gaped at .052. I still have a light ping when under a load at approx 1/4 - 1/2 throttle, and heavier pinging at WOT when shifting.QUOTE]


Run the gap at .042-.044 with the ngk tr6's don't for get they are a colder plug than stock. If you are running more boost 12 psi up I would recomend the gap be run at .036-.038. Try that and see if it helps.

 

+ 1 on decreasing the gap to 36. I had TR7IX gapped at 52 and all I had was spark blowout. Changed to BR7EF gapped at 35 and all is good.

 

Thanks for the input on the plug gap. Keep in mind though the pinging started PRIOR to changing the plugs.

Unfortunately it may be a while before I get to regap. Someone tried to steel the truck last week.

 

I thought you said the truck was stock but later said you had a predator ...

Which is it ?
I have never / rarely seen a truly stock truck ping on good gas.
if your tune is truly stock then throw away the predator and get a good tune from someone that knows lightnings

if you are pinging at stock boost the LAST thing you want to do is add more boost..

Or just ignore all this and listen intently for the big BOOM

 

It's stock and pings. I couldn't put a program on it because it made it even worse.

 

I once had a similar problem. Longstory short, it was a split in the vacum line elbow on the lower plenum. Its possible to reach your arm down there and feel if its dry rotted. It is typical for this elbow to dry rot etc. and does allow unmetered air in. Mine threw a code bank lean sometimes not always after I would clear it with the handheld.

 

It's not likely your plugs are causing a "pinging" problem unless they were too "hot" of a heat range - hotter than a stock plug in your case - or the wrong "style" of plug installed or occasionally improperly installed. If you had too wide gap of a gap, and were having a "spark blowout", the engine would miss and stumble and stutter - but wouldn't have a "pinging" sound - it would just run like crap.

"Pinging," if that's what you hear, usually comes from something too hot in the combustion chamber igniting the fuel mixture before it should: such as a glowing spark plug from the wrong heat range plug, a heavily carboned up chamber surface (the carbon itself can "glow" igniting the fuel mixture), improper ignition timing (usually shows up any time you're under "load"), an excessively lean fuel mixture, and poor quality fuel. And unless it's a fuel quality issue, it generally won't go away on it's own.

If it were me the first thing I would do is restore all parameters (timing back to stock) in the CPU back to stock. Then drain all the fuel from your tank and refill with fresh fuel from a "new" station that has new tanks - thus hopefully eliminating fuel quality as a possible problem.

 

+1 on checking and changing the fuel

 

Where exactly is it your talking about?

Thanks.

 

Sorry I said plenum. I meant lower intake backside its a little hard to get to but possible to reach down there and feel the elbow.

 

Well guys, almost a year later and STILL having the same problem. Diablo you have a diagram on where I'd find this?

 

Bet you still did not have the injectors gone through huh?

 

Negative. I had the truck dynoed and they couldn't figure out what was wrong with it.

 

I'm amazed. Most Lightning have pinging for just a few seconds -- just before a rod exits the side of the engine.