by Rob Turbo » Fri Dec 05, 2014 10:22 pm
I'm not trying to add extra boost, I'm trying to restore boost to standard, I don't mean the car is a bit under powered below 2K RPM, I mean there is no power at all below 2K RPM, to pull away you have to rev the engine to about 2.5-3K RPM and slip the clutch until you're up to speed, if revs drop below 2K while driving you cannot accelerate, you have to change gear, it's not a gradual thing, it's like a switch, under 2K, no power, 2K+ loads of power (well, as much as can be expected from a 1.6 diesel engine!)
I read somewhere that a lack of back pressure at low RPM after removing the DPF causes delayed boost, then boost spikes at higher RPM, that's why I went down this route, but now it looks like something else is the cause of the problem. When I service it I'll give it a good check over for mechanical faults, then move on to a diagnostic session with PP2000/Diagbox, then try replacing sensors.
Because the DPF had already been removed when I bought the car I don't know when this problem started, before or after DPF was removed.