please help! white smoke, random misfire

[TimB]

I am a rookie diesel technician with nobody here to assist me. I am working on a 2006 f-550, 37,000 miles. Vehicle intermitantly blows white smoke (smells like fuel) and will show random cylinders misfiring under load, according to power balance. Originaly replaced egr valve for codes and failed ids test. After replacing 7 egr valves, still cannot get one that passes the test when hot. So, i decided to disconnect the egr valve and test drive to elimate the possibility that the egr valve is causing my concern. Concern still happens with valve disconected. Im ashamed to admit it, but i have replaced a lot of parts already. Replaced intake and turbo due to excessive coking from egr valve. Replaced all injectors, due to cylinder contribution codes and rough idle. Idle is now smooth, but still smokes and misfires under load. Fuel looks ok. Fuel pressure drops to 44-45 psi under WOT while driving. 50 psi at idle. I know this is at the bottom of the specs. But, could this be my concern? Any help would be greatly apreciated.

[Keith Browning]

Welcome to the DTS Tim. Sounds like you are getting your ass handed to ya. I do have to ask, don't you think after the 2nd EGR valve the problem might be something different? Think about that. You have verified fuel pressure while driving - GREAT! I would not be overly concerned with 44-45 PSI for the moment. Do you have any DTC's? Let us start there, reconnect everything, clear the DTC's and road test the truck. Rerun KOEO, KOER, Injector electrical self test and go from there.

[TimB]

Well, i kept replacing egr valvs since the ids test would fail when it gets hot. Even the one i have in there now fails. Thats why i have been driving the truck with it unplugged for now - to eliminate the possibility of if being bad just for now. T

 

Cleared codes, test drove, retrieved cylinder contribution codes for #1 and #2. checked eb tube for blockage - ok.

 

Ford F.S.E. came out today and did not have any definate ideas.

 

Some times one cylinder will misfire for 30 seconds to a couple of minutes, then another cylinder might misfire for a little bit,and so on. Seems to be worse when cold. Sometimes the truck will run great. I have 35 hours in this truck and starting to lose my mind. (and lots of money)

[BrunoWilimek]

Fuel looks ok.

I would start with more than a quick visual inspection of the fuel. Drain a good size sample into a clear glass bottle and put in a freezer for a couple of hours. Then, inspect it for uniformity and colour. It could have poor quality fuel that is gelling or have some water in it. The usual cause of excess soot(as mentioned by you) is excessive idling or low quality fuel. Since you mention the problem is worse cold, the second one could be an issue here. Also, does it have the latest calibration update? You have already replaced the injectors, but has the oil been changed at recommended intervals? How did the injectors look? Any signs of leakage past the copper washer? White smoke is usually unburnt fuel and you mention the smell as being fuel, so I keep coming back to a fuel issue. Very light blue smoke can sometimes be mistaken for white smoke, but with the other symptoms listed, I think we can rule that out. Try putting an additive in the fuel. PM22B or PM23B as appropriate. Another reason for white smoke is too low a combustion temperature(hence the white smoke from a diesel exhaust with poorly working glow plugs). Antifreeze can also show as a white smoke if being burnt in the exhaust, but the smell would be different, and you would have other symptoms such as disappearing coolant.

[Alex Bruene]

And, don't forget, gasoline will burn white. Check for the presence of gasoline by taking a match to a SMALL sample of fuel to see if it will burn. I've seen several a tech. chase his tail for similar concerns because it was running on gasoline. Also, what is the ICP doing during the concern? And, did you torque the new injectors to the proper specification?

[Tony302600]

 

Cleared codes, test drove, retrieved cylinder contribution codes for #1 and #2. checked eb tube for blockage - ok.

 

 

I had a similar problem, hotline engineer said that since retrieving contribution codes for #1 and #2 and them being one after another in the firing order, to start watching FICM SYNC, and SYNC because he was thinking that there was an issue with the crank sensor trigger wheel ( or was it cam trigger ) wheel. I think that is where your headed. Make sure you monitor RPM signal, FICM SYNC and SYNC as a bar graph....Take the IDS and make recording's. If all is ok, i would take the cam sensor out, check it, if ok, voltage drop the wires to the PCM, then obviously make a scope reading. That is where I think you are heading.

 

The EGR valve is another issue.

[mchan68]

And, don't forget, gasoline will burn white. Check for the presence of gasoline by taking a match to a SMALL sample of fuel to see if it will burn. I've seen several a tech. chase his tail for similar concerns because it was running on gasoline. Also, what is the ICP doing during the concern? And, did you torque the new injectors to the proper specification?

Good call Alex. Methinks GASOLINE. Just for your info, a 6.0L that's been gassed up tends to sound quieter than normal, idling. How poorly it runs depends on how much of a percentage dilution you have. At this point, I suggest draining it completely empty, and filling it up with known good fuel.

[TimB]

It does have the latest calibration. Old injectors did not look too bad. ICP is around 670. Did not notice any faults while monitoring RPM, FICM sync or SYNC.

Put fuel in freezer – no signs of water or gelling. Also, fuel did not light with a match. Although, im not sure this fuel smells right. Monday I will try to drain the tank and get known good fuel.

[snw blue by you]

Clear your head, walk away from the job for a few hours or the day if you can.

 

What you need to do is follow the diag worksheet from the start.

 

Forget about what you did in the past, start fresh from step one, do not skip any steps and legitimately perform each step.

 

Go to the PID monitor list (can be found on Power Stroke Central)

 

Perform a good roadtest and get a few recordings. All this will help you in the diag process.

 

It is pretty obvious that diag by parts replacement is getting you nowhere fast.

 

Remember the KISS rule,

 

Keep It Simple Stupid, and make no assumptions. Keep us posted, it will get fixed.

[LARRY BRUDZYNSKI]

I think Stephen has the right call, put everything back the way it was and follow EVERY step in the tree, no matter how simple it seems, this sounds like something small is messing up the truck. You have hit it with all of the big hitters and is not making a difference, start at the beginning and work forward.

[Jim Warman]

I'm going to pipe in along the same lines as Larry and Stephen.. Every time a job has me snookered, it's because I'm not paying enough attention.... "Sufficient good fuel..." is a lot different from the "Oh, yeah.... it's got gas" we all usually give it on the first go around. And that's not the only step most of us fudge on the diesel diag sheet....

 

Most of the time, we can usually get away with it... because the basics are either OK or we run across something in our diag that nags us back to one or more particular basic step.

 

Most of my time is spent diagnosing jobs that "don't want to be fixed"... Sometimes, the tech I inheritted the job from will get nasty with me... "I already checked that....".... I have no doubts that he did, but that's why they call it "double checking...".

 

Now is the time to step back and catch your breath.... You are feeling frustrated and that is the first hurdle to clear... When you get back to the truck (I'll bet Larry can SMELL the analogy coming later), pretend that you inheritted this job from another tech. Start with step 1 in SSCC.... Even if you are positively, absolutely, catagorically sure that there are no TSBs for your symptoms... run OASIS. Got DTCs? Enter those manually in the concern code boxes. You admit that you are "green" when it comes to diesels.... Now is the ideal time to get a big part of the learning curve out of the way.

 

Nothing yet? Start with Box 1 on the diag sheet.... and be careful and critical. Use the Performance Diag section in the PC/ED if you're unclear on what and how they want stuff checked. (Go to section 4 in the PC/ED manual....). If there is ever any question on oil quality or level, change the oil and filter and be done with it.

 

Take each step, one at a time.... Do what that step needs. If you find nothing, you will still have had a dual purpose... first in learning the steps (without some experienced guidance right at hand, this gains importance)... and to be precisely sure that this particular point is not contributing to your concern.

 

Yeah, it can be time consuming... but it looks like that's a given on this job.... Shit happens..... All we can do is deal with it and learn from the experience.

 

<When is this windy old bastuhd gonna stop?>

 

The analogy.... The dog refuses to fetch the stick.... Like the truck, the dog means us no ill will.... he isn't stupid and his main goal in life is not to give you an inferiority complex... The problem is that we have to find how he likes the stick to be tossed.....

 

An observation... we are seeing more and more "bad" new EGR valves. I am still "personna non gratta" on message board, but I understand that a lot of guys are having to go through several new EGRs to find one that works... FWIW, I don't know if the valves are onion made or outsourced offshore.... as far as I'm concerned, one is a bad as the other.

 

A SWAG.... white smoke? Yeah, I see you mentioned it smelled like fuel.... I can't ever trust my old honker and usually get multiple second opinions.... Does it eat coolant all the same?.

 

I spend a good deal of time "lost in thought".... Mostly, I suppose, because it is unfamiliar territory... Check out the soon to be new thread "P1102".

[TimB]

Well, im still getting nowhere with this truck. I have drained and replaced fuel and both filters. Swapped out a new F.I.C.M., swapped out IPR, and went back over diag sheet. Still not coming up with anything conclusive. Both hotline and F.S.E. are out of ideas. I did notice when performing KOER test the engine smooths out. What is the P.C.M. or FICM do to the engine that makes it smooth out? I would imagine it raises the IPR. However, if i command the IPR using dataloger, it doesnt smooth out. I have no idea what to check or try next. If anyone has any ideas i would greatly appreciate any input.

[Bruce Amacker]

I did notice when performing KOER test the engine smooths out. What is the P.C.M. or FICM do to the engine that makes it smooth out? I would imagine it raises the IPR.

That is correct. It raises IPR/ICP (which advances timing dramatically), opens and closes the EGR, and cycles the VGT to make sure all of the feedback devices respond correctly.

 

However, if I command the IPR using datalogger, it doesn't smooth out.

 

Is the EGR still unhooked at this time? It may be in this time area that your smoothness occurs. Look at cylinder balance and see if the misfires are all associated with one bank. Remove the secondary fuel filter and fill the housing with PM-17 fuel conditioner and see if that makes a difference. Bad fuel CANNOT be spotted in the bay using all available methods discussed, I've had bad fuel that passed every backyard test and still cleaned my clock. Running the truck on a very rich mixture of additive usually identifies bad fuel or an injector problem.

 

What portion of the EGR test is failing? Have you run the test with a new EGR plugged in, but not installed in the truck? It is possible for heavy loose carbon deposits to cause a new EGR to stick quickly. The next time you have it out, clean the hole with a wire brush and go to WOT with it running to clear out any loose stuff that's handy.

 

I have no idea what to check or try next. If anyone has any ideas i would greatly appreciate any input.

What is Mass Fuel Desired at a hot idle? It is usually 10-14mg.

 

Has the oil been changed during this process? I'm wondering if aeration could cause your problem.

 

There are some really good guys on this forum that keep a close watch, post your findings and you'll get responses quite quickly. I'm only a couple of miles from you in Strongsville, too.

 

Look closely at the banks in CylBal.

 

Good Luck!

 

 

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[Jeff_E]

Quote:

I did notice when performing KOER test the engine smooths out.

I had something similar a few years ago. I noticed that when I pulled up the power balance test and took active control of the injectors (without actually shutting any off) the engine would smooth out. When I called hotline with this information they came back and told me to suspect a damaged crank tone ring tooth. Sure enough that's what it was. The PCM and FICM are constantly calculating cylinder contribution based on the crank signal and compensating for weak injectors by varying each one's individual duty cycle. When you take active command of the injectors during a power balance test by pushing the pound sign, (or whatever the button looks like now) - this compensation strategy is shut off and each injector is given the same duty cycle. If you try this and your problem goes away, I would use the oscilloscope function and look at the crank signal, if it's glitchey, then remove the crank sensor and look through the hole with an inspection mirror (if possible)while turning the engine by hand to carefully inspect each tone ring tooth for any nicks.
If however, the active control of the injectors doesn't have any effect on the way it runs, then disregard.

[TimB]

oil has been changed. mass fuel according to IDS is .40gr.

I removed egr valve again, and noticed what appears to be some fuel in the intake (not coolant). Maybe its running way to rich?

[TimB]

if im correct .40gr converts to 25.9mg.

[Bruce Amacker]

oil has been changed. mass fuel according to IDS is .40gr.

I removed erg valve again, and noticed what appears to be some fuel in the intake (not coolant). Maybe its running way to rich?

Even if it was running pig fat it would not have fuel in the intake unless there was a valve train problem. See if this liquid is water soluble by mixing it with some spit. Drop two drops of water onto the carbon inside and see if it bubbles up (oil/fuel) or oozes in (coolant). Taste the liquid to verify it's chemical makeup. If it is sweet, it is coolant, if it is oily, it is fuel. (this info came from an old curmudgeon who prefers to remain nameless) Scoop a bit of the soaked carbon out and see if it ignites with a match easily. (if it's fuel, I would think it would ignite easily)

 

Compression test in IDS is perfect? Balance test shows which cyls/bank dropping out?

 

 

24mg shows it's having a tough time running. Was there any change after the injectors were replaced? I assume you drove it hard to bleed the air out of it?

 

 

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[TimB]

Tasted the sample definatly not coolant. The carbon is very tacky.

 

Relative compression is still perfect. Power balance is very erratic. Misfires jump around to each and every cylinder.

 

Originaly this vehicle only acted up when cold. That is why i replaced the injectors. After replacing injectors vehicle ran great. Returned vehicle to customer. They drove it for 300 miles and now it runs worse than ever before. As of today, the vehicle has hardly any power at all.

[Bruce Amacker]

 

Even if it was running pig fat it would not have fuel in the intake unless there was a valve train problem.

On second thought, if it misfires and the EGR is open, it could bring fuel into the intake. My apologies.

 

You said you changed the fuel- does that mean you drained and refilled the tank?

 

What's the consensus of the rest of the lurkers- try a FICM or PCM? I have a both but I don't know about PATS on the PCM.

 

I'm still thinking bad fuel for some reason. Didja try PM17 in the FF?

 

 

 

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[LARRY BRUDZYNSKI]

Something still doesn't sit right, You changed out the injectors for running bad when cold. When you did, did you check the cac and hoses and connections all around, retorque clamps check for oil or fuel in the clean air side? Also did you happen to check the injector harness for problems, we had quite a few with intermittent problems, and by the way are a real bitch to get the right one. You say intermittent miss, I would look closer at the connections on all of the fuel system components, oil intrusion, cracking, etc.... Could you have possibly twisted or cut a injector oring when you replaced them?

 

Shit, give me the good ole' days of Jims era of spraying some carb clean on vacumm hoses to find a leak....

[Mekanik]

Your sure this is fuel and not coolant? I don't mean to doubt you, but how would fuel get into the intake? I mean if there is unburnt fuel could it really go through the egr cooler and pass the unplugged egr valve?

Do you have aerated fuel? That will cause white smoke and random misfiring. I don't think anyone has mentioned that yet. I got some clear hose and put some in the return line and the supply line and watched it while the truck was running on the one I had with aerated fuel.

If it turns out that a fuzzy crank signal is causing your problem, there have been some guys here that have seen rust build up beetween the sensor and the block. Kind of like when rust would build up under a abs wheel speed sensor.

Here is something else I was thinking about. This guy had gas in the fuel system and it caused the injectors to fail. You replaced the injectors, but the fuel still has gas in it. 300 miles later the new injectors have been damaged by the gasoline.

I know that on a 7.3l with bad injectors, if you open the drain valve with the engine running, the idle will smooth out because there is less fuel pressure on the internal components. I have never tried this on a 6.0l, but what do you have to lose. Maybe unplug the fuel pump with the engine running and see what happens.

Remember, your going to find the problem to this truck and it will get fixed.

[JFreund]

i had one that ate my lunch,,, low power, white smoke under load,, ran power palance, missing on 3 to 4 cylinders, erratic, fleet truck, changed 3 injector on warrenty and customer paid for the rest of them,,, 300 miles later,,, yep, it was back,, same thing,,, missing on #1 and #3,, could we have gotten 2 bad injectors,, maybe,,, kept it a few days after replacing 1 and 3,,it then started missing on #5,,,WTF,,, rev it up to see if it clear,,, it then started to miss on #7,,, i had already checked all the basics, fuel, air, sync,,presure at the heads,,,forgot what i was checking next, but forgot to reconnect ICP,,, it stoped missing,, IDS readings of ICP where all good,, so i plugged it back in and the truck was running good,, until wot,, then injectors started droping out again,,, in order 1,3,5,7,,, called hotline,,, and was told that ICP was acting as capacitor and discharging thru the oil and knocking out the injectors,,, first on me,,, go figger

[Keith Browning]

called hotline,,, and was told that ICP was acting as capacitor and discharging thru the oil and knocking out the injectors,,,

Is that even POSSIBLE? Oil acting as a conductor?

[JFreund]

Originally Posted By: JFreund

called hotline,,, and was told that ICP was acting as capacitor and discharging thru the oil and knocking out the injectors,,,

Is that even POSSIBLE? Oil acting as a conductor?

that is what the man told me,,, i changed the icp and it hasn't been back since,,, over a year,,,, i think there is more to it than what he told me, but to push voltage thru oil,,, thats some spike,,,,, wouldn't want my hand in it,,,

[Jim Warman]

Plausible, Keith... Let's not forget that the ICP IS a capacitor to begin with. And, one of the reasons that an oil flooded connector/wiring is such a concern is that the oil can change the capacitance of the circuit.

 

As far as the "mechanics" of a failure like this is concerned, I'm in way over my head... but, let's see if I can embarass myself anyway...

 

A capacitor is simply a temporary storage device.... storing those same electrons that make up the flow of current in a circuit. Once the oil has reached it's "saturation" point, all it will need is some "trigger mechanism" for it to give up those electrons it has stored... in James' case, perhaps the sudden change as 1500ish PSI drops to very low PSI at the end of an injection event is this trigger mechanism. Once the path is established (much like it takes high voltage to ionize a spark plug gap), the electrons can flow until the storage medium is depleted.

 

For why it would take out injectors rather than FICMs.... one can only assume that the PIV (peak inverse volt) characteristics of the FICM circuits could withstand whatever voltage it took to create the path to ground.

 

For James.... The injectors that this truck "ate".... did you have the opportunity to find out how these injectors failed? Was the failure electrical or mechanical? Open coils, perhaps?