Colorado Diesel - Very Slow Start

[steve n]

Hi,

I'd appreciate some advice... I have a 2001 Colorado Diesel, 158k miles.

When I try to set off, it takes 10-15 seconds for the revs to climb from about 800 to 1200, at which point it bursts into life and I'm away, I guess the turbo kicks in (?) and it accelerates normally. This is at its worst when the engine is cold, or at least hasn't been running for a while. It's also worse if everything else is turned on - especially air-con - in which case the 10-15 seconds becomes 20+.

This isn't just the slow take-up of an automatic and a big diesel, it's something not right which started a few months ago.

My local mechanic can't find anything wrong with it, but agrees it isn't right.

It's not as bad after that first set-off, but it isn't right. At one stage I had to do a hill start and it just would not go up - I had to rev it out of gear and put it into gear with a mad lurch forward.

Once it's above that level it's fine, accelerates normally, maintains speed fine.

Could it be electrical, ie when the batteries are a bit low on charge ? I also read something about possible air leaks ?

Any help appreciated.

Many thanks !

Steve