Quote:
Originally Posted by bismic
When you shut off your engine, the EGR valve should be closed (unless it is stuck open). Assuming it is closed and you unplug it, in most cases it will stay closed. This can help w/ the power issue if the valve is malfunctioning. If performance is better with the EGR valve unplugged, you have identified a potential cause. The EGR valve is a common source of "low power" issues. Also, a failed EGR and oil cooler usually means that your EGR valve saw excessivey high temperatures. This decreases its life.
Are you thinking that it is transmission related? Your PCM, ECM, TCM (processors) are all interconnected. They all talk to each other and depend on each other. The Torqshift is a VERY reliable transmission, but it is not infallible by any means.
It is very possible that it is a failing sensor and the PCM is limiting power. Finding this without codes is hard to do.
I highly recommend the new flash, but mainly for cold starts. It is not really geared to restore power, unless something w/ your current programming has been corrupted.
These 6.0's have plenty of power and 7500 lbs is nothing to one that is running properly. Most of my suggestions are to identify FREE things to try before you start parts replacement. One other thing that can mess w/ the power is a restricted air inlet.
I agree w/ cetane boost, but not really seen too many cases where it provided and real noticeable performance improvements. I am glad for Lazyl, but it is uncommon. The U.S. fuel is certainly marginal in meeting the minimum Ford cetane spec of 45 (U.S. cetane can get down to 38). I boost the cetane to avoid building carbon in the system.
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I tested unplugging the EGR valve, and drove it awhile...no significant change in performance.
As far as the it being transmission related, I'm really beginning to wonder. The engine is doing a lot of work...lots of RPM's once if finally responds to the increased throttle....but it feels as if all that power and wleork just isn't getting translated to the rear end. I know this thing is not a dragster, but I'm not a high performance addict either. It's just significantly lacking in liveliness, and responsiveness to throttle input. I can get it to run 70mph, but only after I've been in it WOT for awhile. Another observation in comparison to other F250's I've tested against, is what the transmission seems to be not doing in my truck. In order to get it to drop a gear, I practically have to put the pedal through the firewall. In others, only slight increase in throttle position, and it quickly gears down and takes off....not mine. I can be running say 45 mph, put the pedal on the floor, count 1000-1, 10002...then it decides to drop one gear and start pulling, the turbo comes up to 25 psi, and yes there is acceleration, but I sure wouldn't put it up against any other stock F250's. If I'm cruising down the highway at 60mph in overdrive, I can put the pedal on the floor and it's as if it never does decide to drop a gear...the turbo spools up and I get acceleration, but it seems to do it in the same gear I was cruising at. All of this is only more exagerated if I've got the camper hooked up. Everything requires much more throttle. I get next to nothing in acceleration until the pedal is 3/4 to WOT. Tested again on a back country hill tonight with camper in tow...pedal on the floor and I couldn't get above 50 mph....yet RPM's were well around 3500 and turbo was at 25 psi. This wasn't a mountain grade hill...just a normal NC country road.
Not sure if they are related, but ultimately I feel like I might have multiple issues (maybe they are related though). One, throttle response is horrible...it takes 3/4's of the throttle travel or more to get it to gear down...and two, when and if it gears down, what the engine appears to be producing just isn't translating to forward acceleration (as if the rear end is geared like an 18-wheeler). Someone asked me if I could spin the tires from a dead stop and hammering the throttle.....absolutely not....not even close!
The transmission doesn't feel at all like it's slipping (if that's even possible with a torqshift transmission)...at least not like a manual transmission with a slipping clutch, which I've felt before. When you push throttle, you want to ask the truck "what are you waiting for"....when I've got that 7500 lbs in tow, it makes you feel like you might have 15000 lbs. back there.
I'm going to take it and have it re-flashed tomorrow...dealer quoted me $38...I'll happily pay that just to rule that out.
