RJ_RS_SS_350

Oh yeah, you had to remove the intake manifold to change the injectors, gotcha.

A bad turbo would help explain why the valves are caked, leaking oil into the incoming air stream. But I would think you would notice a drop in the engine oil level, but it might be a very minor drop.

And then the caked valves could be the source of the misfire. But let's see what the compression test reveals.

Oldblue

White smoke usually means coolant burning off in the combustion chamber, or there’s a new Pope.

drspock

I have not yet checked the compression. I changed the plugs to Delco gapped to .30 and no misfires with the tune off AKA stock tune. With the tune on it still misfires, this obviously would be more boost to 20+lbs and more fuel. Im thinking even though the coils are new 47K performance coils maybe they are not getting the correct voltage. My next step is to do the compression check and figure out the pinout voltages for the coils. A new turbo would be in order at 170K miles im sure.

firemangeorge

So, it looks like you have the plugs gapped wrong.

Oldblue

And you might have damaged the whisker by gapping the plug.

DrLoch

FYW, Sometimes when you up the boost you have to shrink the plug gap. I've had occasions where I've had to close the gap up down to .024/.025. I have also heard of other LNF people who have had to close the gap up. The addition boost tends to blow out the spark.

Look for a post from mississippisunburst, ..... found it. https://www.chevyhhr.net/forums/2-0l...erstand-54290/ He's got his closed up to .020.

Food for thought.

firemangeorge

DrLoch. Not disagreeing that this has worked for others with lots of mods and running high boost numbers.
But, how would this "short gap" affect the 99% of the engines time not running under boost ?

drspock

Thanks, i bet that will be the solution for my misfire seeing how changing the gap to .030 made a big difference. Now the misfire starts at 20lbs as before it was at 10lbs. Originally the tune and high boost worked fine with stock gap, so something has changed. Im thinking Turbo is leaking water and or oil into the system, or compression issue. I will check compression this week and re-gap to .020, for trial run. I cant run a catless pipe without white smoke sitting at a traffic light, none with the cats. I think the cats must burn off the water and or oil from the turbo.

donbrew

Are there puddles of water under the car? Steam has to go somewhere.

Oldblue

Coolant will clog and kill the catalytic converters.