wet stacking exhaust on 5 ton

[grunex125]

Today we're back to work on the 817, and this afternoon (as before) I found a serious case of wet stacking going on. I've redone the heads from one end to the other and still persistant white grey smoke still prevelant. My question here for the members is this.

will pressure and fuel supply from the injector pump flood the cylinders with excess fuel even if the injectors are set correctly? Or could there be an oil gallery that is cracked and leaking oil into exhaust?

I'm going to pull the exhaust manifold off the side tommorrow to see if it is just one cylinder that is wet or if it is all of them, but I kind of think with the amount of liquid in the "can" on the side of the motor I think it may be from all six cylinders. ( about a pint)

I have tried different settings with the injectors and have noticed a big HP difference with the settings, even with small amounts of adjustments, but no matter which setting I'm using the wet stacking and white grey smoke is still overwhelming.

I would think that blow by would be more present if I had bad rings, and when I tested for compression in FEb. everything was within limits, so I doubt that rings are an issue.

Any help would be appreciated

Thanks

 

[bearboley]

Faulty injectors will cause that, and so will a air leak in the supply line on a cummins. a small air leak will make a cummins do all sorts of things like smoke white, miss and slopper in the exhaust.

 

[grunex125]

rough idle as well?

I can't fault the injectors, they're brand new

 

[grunex125]

I guess I can't figure where I'd get air from either, all supply lines are tight, and in good shape.

 

[bearboley]

Yes sir. If you rev it up does it blow a big cloud of smoke and miss some might even snort and pop, then cleans up and run right.

 

[grunex125]

It blows a big cloud fer sure, seems to be slow to respond but the cloud of smoke deminishes only a little under heavy load. AS for the idle, it seems to have a bit of a pop like it has a bad valve, but that can't be either because I've put all new valves in and seats as well. The heads were done professionally and even professionally seated. One thing I did notice when I changed the fuel filters the fuel filters were only about a third full of fuel is this normal?

 

[grunex125]

Thinking here............if I have an air leak, where would be some of the comon places I should check?

 

[bearboley]

Should be full. I would say air leak is your problem. Maybe the tank selector valve. I have seen so much as a loose fuel filter suck air and make them run bad. Your valves too tight will cause white smoke also. I think its 72 inch pounds on the injectors and .14 and .24 on valves. Not sure on that.

 

[grunex125]

72 inch lbs on the injectors is way underpowered......... I'd have to check my notes again but I believe they are set at either 65 or 68. At 72 in/lbs. I can barely get the truck running. and when it does run I don't have enough power to shift up out of 4th high on the straight and level road.

what about the fuel primer on the dash? source of air as well?

AS for the valves, I'll run a check on them again in the morning.

Would any of these air leaks cause one cylinder to be "wetter" than the others on the exhaust ports? (I'm thinking no but I could be wrong)

 

[WillWagner]

Run it out of a bucket and see if it runs better. And not wetter, just incomplete combustion. Air in fuel changes injection timing.

 

[grunex125]

will do..... I'll let you know what happens.......

 

[bearboley]

Never thought of the hand primer could be. I haven't worked on those style injectors in a while My 400's have top stops there 6 inch pounds. beside the point. I would check the hand primer and tank selector valve beside seat. My recent experience was with a big cam 400 that I bought out of a field been sitting there 5 years the guy said it needed a liner because it missed bad at idle on one cylinder 400's are low compression and static timed too boo,t to get the big hp out of them the timings slow at idle and yes they will be wetter on some cylinders until you get to operating temp. As I was looking at the truck I seen a small wet spot where the fuel line rubbed the steering box and it was a bit wet I knew the problem at that time. Anyhow new fuel lines and it purred like a kitten.

 

[grunex125]

reason I asked about the hand primer is because the floor of the cab has been showing signs of fuel. Dust is collecting around the area so I know there is a leak there somewhere. It doesn't seem real "wet" but I do know the fuel filters were almost drained when I changed them and this would seem like a likely source for air. Maybe when the engine is running it may be sucking in more air than I realize.

 

[grunex125]

Today I took the fuel primer line off the side of the intake and plugged it with a qtr inch pipe plug. when I got in and fired it up it seemed at first to run like it used to but after it warmed up the color of the exhaust changed and lessened. I set the engine at a high idle and let it run for an hr or so. when I went to shut it down the exhaust was a whole lot better. A little blueish mixed with black, but I think I got to the bottom of the wet stacking issue.
Black exhaust I can live with, and the blue smoke may still be remnants of the oiled up engine, but if not at least I know that I'll be needing a set of rings and a honing next time I open it up. (blue smoke was easy to diagnose at least) I know none of the rings are broken, but after sitting for three years it is a good bet that they are at least stuck or not functioning as they should. With the problems solved or at least identified, we went to work setting it up for chopping silage in a week or so. turning out to be a pretty funky mod, but then again silage is bulky, and these beds really aren't big enough to haul silage all by them selves so ..............on with the side boards!!! (buying new chopper wagons are not an option for me this summer so we make do with what we have)

 

[bearboley]

Glad too hear your on the right track with your problem. post some pics when you get in the field

 

[grunex125]

sure thing.