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Dear James, I listen to you show every Saturday and I have never heard this question before on a 2004 Ford Power Stroke 6.0 liter diesel. My truck has 146,000 miles on it and occasionally it will not take the “gas” when I push down on the accelerator pedal. There is a cloud of black smoke when this happens from the exhaust and the engine does not have any power. The truck will hardly pull off from a stop sign. If I stop and put the truck in park and rev the engine the problem clears up and it runs fine till it happens again. It seems to be no set pattern to acting up. There is not a “Check Engine” light on the dash either. My repair shop says unless it has a code that turns on the “Check Engine” light they can’t help me. What could the problem be? Brent in Apalachicola

Happy New Year Brent! The good news is that this is a problem that you may be able to fix yourself with a little elbow grease and throttle body cleaner. What is happening is the EGR Valve is getting stuck in the open position. On diesel engines the EGR is open at idle and then closes when you push on the accelerator pedal. If it does not close then the engine produces a lot of black smoke and has little power when it tries to move. To solve this problem you will need to remove the three little bolts that hold the EGR on the engine. Now do your very best to clean all the carbon off of the EGR valve and all the carbon that has collected under it. If this solves your problem then make sure that you use Rotunda Cetane Booster from your local dealership. It is the only diesel fuel additive recommended by Ford for this engine. If you use this additive it will help remove the carbon deposits that are there and keep it from “coking up” in the future. The Ford power stroke diesel along with GM’s Dura Max and VW’s TDI diesel need at least 47 Cetane to operate the way it was designed to operate. Unfortunately our government has mandated that the lower sulfur diesel fuel should only have a 40 Cetane rating +/- two. Even if you buy the best diesel fuel in town it will only have a Cetane rating of 42. That is 5 points less than the engineers who designed this engine would like to see run in your engine. If you use the Cetane booster I suggested, it will raise your Cetane level 9 points. This will save you a lot of money and down time in the future. As a side note: a lot of construction companies insist that the diesel fuel they get from their suppliers have a Cetane rating of 50. This has stopped them having problems with injectors, EGR valves and other assorted engine maladies from running too low Cetane rated fuel. Live long and prosper in 2011, James Morris


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