Thread: Fuel starvation and pump Q's

Here 's a riddle.
My car - Disco td5 manual.
Since i got it and being my first diesel,i noticed that when accelerating with full throttle, it would rev up to 4k rpm and then it stops reving like it hits a rev limiter.
Not like going into safe-limp mode after overboost situation.
I thought that it was normal behaviour.
Nowdays and after 20k klms(total 172k klms),i installed a stage 1 Td5 alive map with a nanocom - i have already removed the cat and egr and adjusted the boost a tad before the 1.3bar(230Kpa) overboost limit - i have many nanocom fuelling files-diagrams saved,i don't see anything strange,maf readings seems ok,sensors are clean etc,the only thing thats not measured is fuel delivery.
I also suspected the Crankshaft position sensor,is it possible to stop reading right past 3800-4000 rpm? but ok for the rest of rev range?
After tuning,it became a different beast,on 1st and 2nd gear it revs past 4000 rpm and up to 4500 like a gasoline engine but on 3rd gear and up,the "rev limiter" behaviour became more intence-apparent-obvious (excuse my english),about 3800 rpm,like the fuel pump relay switches on and off for (milli)seconds?
I then intalled a mantec snorkel,and no more over 4000 rpm again(like before tuning),but thats not my problem,i don't drive like this anyway,the fuel cutting? is my concern now.
And now the big question,it might be the fuel pump??(fuel starvation)??
It's definatly not overboosting-safe mode situation,i've tried lower boost.
Is it a trial and error thing(install a new pump and see)??
Sorry for the long post.
Cheers.
Andrew.

Thanks a lot mate and what a coincidense,
just this morning,i had a conversation with a buddy with a Def,he cleaned the whole thing (pot and gauge filters) and he observed a big deference.
A nice weekend project for me then..