Random ploofs of smoke

[Daniel McCurdy]

I just noticed that under wot acceleration usually in 4th gear there will be a large ploof of black smoke then it goes away then it comes back, it keeps going on and off. It's not really a problem but I was just wondering if that's a sign it might be time for some injectors and/or pump.

 

[Big Bart]

Would you say that is new issue, or you are just noticing an existing issue? How many miles since injectors and a IP pump rebuild?

If a new issue could be an injector or IP getting a little tired. But if you are just noticing it, then perhaps it has for sometime, and your IP is turned up a little high.

Since it is only WOT I would monitor, not sure you need to take action. However if you have rough idle or other performance issues might be getting ready for injectors and a IP rebuild.

I used to notice more at night due to lights behind me I was blowing a little black smoke occasionally while at 65mph, after putting in new injectors I have not noticed it again. But did not really notice it in the daytime.

Let us know.

 

[Daniel McCurdy]

It's probably been doing this for a while I just didn't notice it till now. As far as I know pump and injectors are original 195k miles. It's definitely not because it's turned up too much as when it's unloaded no weight going uphill between 50-60 wot it won't gain speed and depending on the hill it will loose speed UNLOADED. It starts up and runs great no issues there.

 

[IDIBRONCO]

As far as I know pump and injectors are original 195k miles.

With this in mind, I would just plan to replace the pump and injectors. The service life of these parts usually ends around 120,000-130,000 miles. They can run longer, but there's no real advantage to doing it.

 

[Kevin 007]

I have noticed this on several IDI's. While maintaining a steady throttle input (not necessarily WOT, but enough to create steady smoke), there will be occasional puffs of heavier smoke that come and go. Never did figure it out, this was on new or fresh pumps, from reputable pump builders.

A thought was, CDR gasses accumulating and dispersing into the intake irregularly, but that really shouldn't be happening unless the CDR was pulling oil from the valley, which these trucks were not doing.

Or, fuel pressure changes/fluttering with a mechanical fuel pump, changing the timing rapidly. But mine have all been on E fuel pumps and steady pressure...so that kinda rules that out to.

 

[silexis]

I get a lot of smoke when going uphill and accelerating after loafing along on the flat. I assume that it is just oil accumulating on top of the head and then running to the back and down the valve guides when I go uphill.

 

[Oledirtypearl86]

My money is on injector. But spunds like ya need a pump too or put injectors and turn your pump up

 

[Garbage_Mechan]

I had that issue on my 6.9. Checked everything else then put a rebuilt pump and new injectors. Problem solved! I think sometimes as the pump and injectors wear it is so gradual we don’t notice. There was a huge increase in all around performance after the pump and injector rebuild.

 

[IDIBRONCO]

I think sometimes as the pump and injectors wear it is so gradual we don’t notice. There was a huge increase in all around performance after the pump and injector rebuild.

Because of the cost of replacements (quality replacements) this is how it usually happens.