Ok, so I've got one of the early 2003 6.0Ls with 250,000 miles on it. I stopped driving this as my daily driver at about 150k, and turned it over to one of our landscaping crews. Recently, we've had a host of issue regarding power so we've kicked it over a few times to the local mechanic who has successfully worked on it in the past.
Over the past 1-2 years, we've had the majority of the injectors replaced, turbo replaced within the past year, ICP
sensor, fuel regulator, and some other misc items replaced.
Yesterday, I cut out and wired out a replacement FICM
x3 pigtail, as the tabs had worn off and we were losing connectivity at the slightest touch of that connector to the FICM
. With the new connector on, I no longer get any "stall" type results when touching this connection while the truck is parked. Seemed the connector solved that issue. All new wire connections were soldered, and then placed in heat-shrink tubing. I wrapped all new wires with heat-reflective tape, as the original wire jackets were melted together pretty good.
However, I took the truck for a test drive this morning, and got about 5 miles down the road and started to experience some issues around the 1550rpm range, that lasted until about 2200/2500rpm range.
I ran the truck with WOT
as much as I could initially, and it responded great. It was really nice to drive this truck again, as it was the first vehicle I ever bought when I was 18 years old back in 03. At around 5 miles into my test drive, I was doing approximately 40-50mph.
I then turned on to some residential streets, which required that I slow down along the turns, and that's when I began experiencing some lag & issues around 1550 rpm. When I began driving from a dead stop, I experienced what felt like a fuel delivery issue around 1550rpm, but kept pushing down the pedal with a WOT
, and pushed through any lack of power. It felt like a sputter/intermittent fuel delivery. However, when I backed off the throttle and came into the 2000 rpm range, I experienced what felt like a premature turbo blow back/waste gate discharge. I could hear the air being discharged from the turbo excessively during times that I would expect the engine to just throttle down without any noticeable sounds from the turbo.
Not sure if this is related, but I noticed the air was blowing through the defrost. I quickly chased this down to a disconnected wire connector on the vacuum pump, which then ran for a minute or so to build back up and then the a/c blew from the vents fine. I assume the vacuum operation of the truck cannot be related to any of the acceleration/throttle/turbo issues around the 2000rpm range, but wanted to mentioned it just in case.
No check engine light, but I also haven't hooked up a scanner to it yet.