GregH Posted September 26, 2009 Share Posted September 26, 2009 After I drive this customer's truck about 10 miles at 60mph, bring the vehicle to a stop, then roll the throttle to the floor, the enigne misses it's ass off. Cylinder #2 starts the show, with about 4 misfires. Then #8 gets into the act, and before 2 and 8 go back to hitting, 4 and 6 also drop out for a few crank rounds. Vehilce rolls blue/white smoke when this happens. If the road speed is above 70, then the engine will never misfire. If it is less than about 45, it also acts fine. It's only at that sweet spot of about 60, and it has to be sustained for at least 7 or 8 miles. Maintenance records are up to date. Fluid levels are optimum. No history of other repairs, and the calibration is up to date. No codes stored in memory, and no programmer used. Fuel quality probaby isn't an issue, since this concern has been going on for several tanks of fuel from different locations. I did crack the connection between the horizontal and vertical EGR coolers and looked for coolant - it's dry in there. When I removed the lower CAC tube connection, about a tablespoon of water came out. But we have been having nonstop rain for the past two and a half weeks here, so I'm not too worried about that small amount of water. Anyone have an idea? I'm stumped... Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted September 26, 2009 Share Posted September 26, 2009 This stinks of a foul injector but the scenario is really strange and may be distracting to your thought process. In all Power Strokes a fuel leak or sticking injector pintle will almost always affect the other injectors in a cylinder bank... right? Take away the odd circumstances and just look at what is happening. This may be the time to make an educated guess. Good luck my friend - this one sounds possessed! Quote Link to comment Share on other sites More sharing options...
MattB Posted September 26, 2009 Share Posted September 26, 2009 SOunds like fuel injector sticking open. Would explain the smoke and the misfire that spreads to the others on the bank. Crack the lines loose at the injectors and catch the fuel in clean tissue paper and check for glitter. We had one similar a few months back, turned out to be a hi psi pump coming apart, and the metal would intermittantly stick injectors causing a misfire that would come and go, and it would also intermittantly stick the VCV and PCV causing a buck and surge between 55-65 mph. The main cause of a failed hi psi pump is water in fuel, BTW. Quote Link to comment Share on other sites More sharing options...
rlchv70 Posted September 28, 2009 Share Posted September 28, 2009 May also be the injector harness or an intermittent connection between the harness and the injector(s). Quote Link to comment Share on other sites More sharing options...
GregH Posted October 1, 2009 Author Share Posted October 1, 2009 Well... A few things have happened since I last posted. It was last Friday when the customer brought us the truck, late in the day, and I told him that we wouldn't really do anything to it beyond make our recordings in what little of the day was left. I recommended that he take it on his planned trip to Picayune (some 250 miles away) and bring it back Monday. So, Saturday sees the end of the rain. Temperatures start to even out, and Saturday night was beautiful. As a side note, I purchased a telescope two weeks ago - a sho-nuff Meade computerized "see 'till the beginning of time" telescope, and it has been sickening me to see it in the dining room, all set up, calibrated, and ready to go. Saturday was it's "first light" and that is a whole story unto itself! www.cloudynights.com Sunday dawned bright and clear, and it has been crisp, semi-fall weather ever since. Monday morning, my favorite truck pulls up... The owner said it messed up over the weekend a little, but not as much. Over the past few days, I have driven it through 6 drive cycles of 10 miles each, and never got the first misfire out of it. In fact, the truck is sitting in my driveway right now, 60 miles away from work, and it didn't miss a lick the whole way home... No codes, calibration is up to date, fuel looks and smells right, and maintenance is up to date. It messed up during our forty days of rain, but once it stopped the truck runs right? WTF? The only thing I have seen that could possibly be related to operating the truck in the rain is an accumulation of water in the CAC - but even that was only about a tablespoon.... I'd buy an injector issue. In fact, I would love to find an injector issue - or any definate problem for that matter. But I would think that an injector electrical concern would set a code. An injector mechanical issue might not set a code - it misfires for such a short period of time that it doesn't set a contribution code. But, which one? #2 dropped out first, followed by #8 and then #6 and #4 together. But that is off of just one recording.... Egads.. Quote Link to comment Share on other sites More sharing options...
Aaron Posted October 2, 2009 Share Posted October 2, 2009 Isn't there a rough-run concern related to that water in CAC/white smoke during rainy conditions concern? I can't remember the bulletin number offhand. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted October 2, 2009 Share Posted October 2, 2009 I just used that TSB (08-25-01) and it only addresses the white smoke issue in damp/rainy weather during acceleration and so forth and so on.... Quote Link to comment Share on other sites More sharing options...
Aaron Posted October 2, 2009 Share Posted October 2, 2009 Couldn't remember offhand, thanks Keith. Quote Link to comment Share on other sites More sharing options...
MattB Posted October 4, 2009 Share Posted October 4, 2009 Any tattle tales in mode 6? Like misfire count way higher on one cyl? If you find an injector problem, make sure you check for the glitter in fuel. Quote Link to comment Share on other sites More sharing options...
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