Acceleration Cutting Out.

[Peezen]

Hi all, happy holidays

As I dig deeper into getting my new beast back into shape I am dealing with the next big issue: Acceleration cutting out.

I have a 2004 4.8is.

What is happening is that more often than not now, after idling for a while to warm up the X or after driving for a bit, I lose my ability to accelerate. Originally I thought it may be a transmission issue, but it shifts fine when everything is going well, and I can feel it shifting through all the gears in manual mode, and there are no issues going into reverse or drive right away.

What happens is that when I push the pedal I accelerate very slowly and even the revs are slow to climb. I can barely get past 20km on a small hill, and the revs will slowly climb to a shift point, and the X will shift, but continue with the slow acceleration. If I turn on and off the X the problem vanishes and I can drive normally until it starts again; push on the accelerator and very little response.

Today to tried tapping on the pedal and I was able to get a bunch of grunts and surges before it cuts back to nothing.

There are NO transmission codes, no engine codes at all. There are NO dash lights or messages in the message centre. I have the Schwaben/Foxwell BMW reader and I am getting no codes when this occurs. The only code related to the drive at all is a stubborn oil wear code for ten tanager case.

When it’s not happening the thing is a beast and accelerates like a monster.

Am I looking at an issue with the accelerator pedal? Or the throttle body? To be able to trust my new friend in the winter here I really have to get this issue sorted out, but without any codes to start with I’m wondering if anyone in here has any experience with this?