Cylinder #3 contribution, injector?

[Tiha]

Latest problem. Truck has been sitting, it has been very cold. Started it up last night. Kicked high idle on to let it warm up. Ambient temp was like 25 degrees.

Gray haze, smoke was dense. Truck started missing.

Eventually stopped missing, still had gray haze from exhaust but not as bad.

Cleared up after it warmed up. Took it for a drive. It stopped missing, started running great like normal, burning clean.

I have had it in my head after doing other troubleshooting that my extended crank is most likely caused by excessive return from an injector. I have been waiting to get the truck in the shop and torn down for other work in order to actually flow test the return from the injectors.

Last fall I did extensive testing and monitoring. Truck didn't miss or show anything like this then. Fuel trims were good, contribution was good. I had random extended crank. So I had it in my head it is an injector already. I did all the lpfp testing, did all the hpfp testing. Checked as much as I could without tearing into it.

Is that likely possible? 186k miles. No additives ever, or bad fuel, or really any trouble out of this thing.

Next question would be, do all 8? Or just the one?
Seems like I read guys say these injectors only last 200k, then in the next sentence I read that they never fail.

Road trip we took last fall MPG was down about 1mpg. Where as it had run around 18mpg it's whole life, this trip it was running right at 17mpg.

It is deleted and no extra fueling, stock fueling.

I love this truck, so I am not opposed to doing all 8, but if it is a waste of money and time I would rather not. Since it clears up I am assuming it is probably not a bad or cracked valve. I suppose it could be a lifter? I am running 0w-40.

Any thoughts?

thanks,

 

[Petro]

Have you had it on a scanner to check balance rates? Pulled codes yet? I'd check the hpfp out and make sure it isn't sending metal through your fuel system. If all of that checks out, replace the one injector and run it.

 

[Tiha]

Have you had it on a scanner to check balance rates? Pulled codes yet? I'd check the hpfp out and make sure it isn't sending metal through your fuel system. If all of that checks out, replace the one injector and run it.

I did extensive diagnostics last fall when it was still warm. Nothing looked out of place. Trims were good, balance/contribution was good. No codes. Pressures were good.

At that time everyone was saying CP4 as well and maybe it is, but it has been running a long time with the "extended crank time" I have been noticing, without getting worse or giving up.

When I get it inside I will pull sensors and inspect again.

The #3 cylinder contribution came up as a historic code, not active code. It was not there last fall when I was doing all the diagnostics.

It is so easy when you are helping someone else troubleshoot stuff, but when you are doing your own it's like your head turns into a pretzel. I gotta pretzel in my head.

So I was kind of looking for you guys to say, yeah the cold miss, the smoke and haze when cold is inline with a bad injector.
And, you better do all 8, or just throw one at it and it will be good.

If this was an old IDI engine, no brainer, do them all. Even my 7.3 powerstroke. Just not sure what is expected out of these injectors.

 

[Petro]

I did extensive diagnostics last fall when it was still warm. Nothing looked out of place. Trims were good, balance/contribution was good. No codes. Pressures were good.

At that time everyone was saying CP4 as well and maybe it is, but it has been running a long time with the "extended crank time" I have been noticing, without getting worse or giving up.

When I get it inside I will pull sensors and inspect again.

The #3 cylinder contribution came up as a historic code, not active code. It was not there last fall when I was doing all the diagnostics.

It is so easy when you are helping someone else troubleshoot stuff, but when you are doing your own it's like your head turns into a pretzel. I gotta pretzel in my head.

So I was kind of looking for you guys to say, yeah the cold miss, the smoke and haze when cold is inline with a bad injector.
And, you better do all 8, or just throw one at it and it will be good.

If this was an old IDI engine, no brainer, do them all. Even my 7.3 powerstroke. Just not sure what is expected out of these injectors.

It most certainly could be a bad injector. If it were me, I'd replace the one and run it, I see them fail on occasion but not enough to do a full set. Lately Ive just been seeing them throw a circuit code but continue to run fine, I replace the one, reprogram the IQA code and send it out the door. The best part about the 6.7 is, it's such an easy job to do injectors.