I just bought this truck and I have no history on it. 2011 f350 6.7. Blowing white smoke mainly during start up and taking off from a stop. Showing codes for #3 and #4 contribution. Exhaust smells like unburnt fuel. Buzz test was good. Compression test was good. Had it hooked up to Ford tech laptop. Shut off computer timing compensation and #3 and #4 drop off the chart and it starts running like crap. Turn computer back on and idle smooths out.

Changed #3 and #4 injectors and replaced both fuel filters. No change. Got a tip that maybe the return line is plugged. Blew tons of compressed air in it attempting to dislodge something. Seems to be flowing freely. No change. Starts right up and idles perfect. Seems pretty smooth when revving it up especially in higher rpm. When taking off from a stop it knocks and kinda surges into 2nd gear. Turbo surges also. On the freeway it's smooth and powerful. Passes cars with easy but does knock pretty bad at first when you put your foot in it. A little hesitation, then clears out.

The engine is fully deleted. No egr. Straight 4" pipe. Unknown tune.

Any ideas?

 

did you input the calibration of those new injectors?

 

Yes. Checked that before swapping the injectors and recalibrated after new injectors.

 

did you scan again for codes? Any present?

What tuner are you using? Have you spoken with them about your issue?

 

Same codes present now.

Have no idea what tune is on it. Previous owner doesn't know either. He bought it from an online repo auction.

 

I know it doesn't help that I have zero history on this thing. Are you thinking maybe the last tune was installed incorrectly or amateur coding or something?

Can I just find someone with a tuner and try out their tune to see if it makes a difference? Once you have a tune loaded to a tuner you can upload to any truck you want right?

 

Most if not all tunes are written specifically for each individual truck depending on what the pcm and TCM strategies are. Those are the two things that are required for a tuner to give you the proper tunes. Unless you go with the canned tunes which most do not these days.

I would buy another tuner that you know is a quality tuner and put tunes on it from a reputable person. I would be doing that regardless if it was having problems or not. A bad tune can wreck a truck and there are many out there.

 

Anything else it could be? I've seen a few reported cases of valve issues and glow plugs breaking off on these early 2011's but if that happened it wouldn't be isolated only in 3 and 4, would cause lack of compression and wouldn't run for long right?

 

If it were valves, you would be down for the count and require a motor.

 

That's what I'm thinking. If it were valves and/or glow plug tip breaking off there would be some kind of mechanical sign. Odd sound, not running at all, loss of compression, not clearing out at higher rpm, etc.

 

If I was you I would buy a tuner from a company you truce for a good tune. Then take the truck to Ford and have them return the truck to stock. Then upload the new tune you got. This is the reason not buy a truck that is deleted without the tuner. From what I understand the truck won't run with the stock tune so you have to upload the delete tune. This may only cost you a $1,000 to sort this out. Not sure the tune will help you but you may have to start from scratch to fix the truck.

 

Taking it to Ford would be pointless. As you said, it won't run without a delete tune.

I've never used a tuner before and don't know anyone that has used one. The SCT X4 seems to be a name that pops up alot with these trucks so I guess I'll go with one of those. Tyrant is a name that I've seen a lot for tunes so I plan to get their factory delete tune. Not trying to get crazy performance increase, just want it reliable.

 

Did you ever figure this out? I'm having a similar issue. Only difference is I get cyl 1 high on contribution and cyl 8 runs slightly lower than the rest. On a cold start cyl 8 will drop to -25 on cylinder contribution after running for about 60secs.....I shut it off and restart and it runs great

 

I did figure it out. The hard way...
Let me catch you up to speed on my whole timeline with this truck. Bought it 2 states away from me for $12,500. Ran fine but had white smoke out the tailpipe mainly only at warm up. I figured worse case it'd need a turbo and or head gasket. Ran some tests, replaced filters, oil, one injector. Ran great but still had smoke. Drove it home 750 miles. No issues other than smoke and check engine light. Got it so cheap I decided to drop it off at a shop and have them deal with it instead of me putting more time into it. 10k later I had the truck back with new heads, 4 injectors, exhaust manifolds and turbo. Still got some smoke on start up. Now is when I realized the knock under acceleration. It was always there but I didn't notice it was abnormal till now. Took it back to the shop twice. They said it was just injector knock. They replaced 2 more injectors. No change. A month or so goes by of me driving it back and forth to work with light smoke on start up, knock under acceleration and intermittent low contribution code. I hook up the 5th wheel to go camping, get 100 miles from home and the #6 rod explodes. Holes through each side of block and upper oil pan cracked. Rod bearings were not seized. Both ends were intact and free spinning. The rod was cracked and/or bent and finally gave out.

Truck sits for a couple months while I scrounge up more money. I go to buy the short block and covid has the plant shut down. About 5 months later I have the short block. A couple months later of me working every other weekend at my buddies house an hour and a half away getting the short block swapped out and now I'm driving it again. Been driving it for a couple weeks. Basically a completely new engine now.

Hopefully your issue isn't the same as mine...

 

Wow that is terrible! I hope it not the same issue. I borrowed a friend's ford software and found injector 4 is over contributing so hopefully a new injector fixes it!