Trans slip? under load then ok?

[megawattmike]

Last week my son called and asked me to tow a trailer loaded wih two cord of oak 20 miles up toward Mt lassen from Redding. All good as normal, for first 15 miles , then on a long grade at about 50 mph (In tow/haul Mode). there was a strange noise from the engine or tranny and I lost power till I was down to 10 mph so I pulled over and stopped. found no apparent problem and the check engine function showed no problem. I restarted and all ok till I hit 45 -50 mph and it repeated. This time I pulled it down into 2nd gear slot and completed the climb at about 25 mph ok. Unloaded the trailer and have had no repeats at all. Any one have any ideas what might have happened. i suspect either trans did not shift properly or maybe a turbo hang up that cleared up afterwards.

[BigGreen06]

Sounds similar to an issue I had with my truck a couple weeks back, going up an incline the truck doesn't want to shift, and you lose power dropping to 10mph. It was a problem with the Fuel Rail Pressure Sensor. Basically the tech said the sensor was telling the computer that the fuel psi at 65-70mph wasn't 22,000psi, but was 600psi(Idle pressure). So they replaced it (under warranty) and no more issues.
This problem will not throw a code, unless you have one of the techs computers hooked up to the truck looking for that specific code.

James.

[megawattmike]

My dealer service writer says he thinks a EGR valve stuck he wants to read the codes to check. I also think you are on to something with the fuel rail pressure sensor. So far my truck has not repeated the power loss episode. thanks for your note.

[ave8tors]

my truck is doing the same thing but i get a code some times fuel rail pressure to low also if you shut off the truck and restart it it works fine until i put a good load on it. but i also think i have a trany problem between 3rd and overdrive put hopefully this is causing that problem