Power loss

Hi all, I have a stock 3L, no mod at all bar a full tig intercooler 3 yrs ago, on the weekend I was towing my camper, weather was warm, I keep losing power around 2500rpm, foot on/foot off would help for a few second but start to die again till it get to about 2-2200 rpm then kick in again, sometimes it losses power just under 3000rpm but is fine above that, no lights, just a loss of power/revs, it has always had a slight loss between 2500-2800rpm but really noticed it this trip, on one hill it had a loss of power & I had to drop back to second gear to climb the hill, it actually got 3/4 temp up, it has never overheated ever on a climb like that.

I recently cleaned the maf sensor 4-6 weeks ago, oil & water is correct, new glowplugs, aux battery replaced 4 weeks ago & cranking battery was shimmed as the loose terminal on the cranking battery killed my aux battery, it has never run better/smoother with good power so this attitude has come as a bit of a surprise to me.

Has anyone sorted this problem completely, I know a small lose of power is common enough but this was very noticeable,

regards

Jim

so no one has experienced this

sorry mate i have a 4.2 not much of an idea with 3ltr

the year model of your gu is in the main grenade era . I think you should do the full nads program on your motor . I have a later model with few Ks so I have only done the catch can at present . there is lots of info here and others with more of an understanding of the issues than me . but at a guess I would think it is overboosting and going into limp mode until you lift your foot off .