Lineal power loss - limp Mode?

[SLX530]

OK.... I have just finished a 15 hour stint over three days of replacing my cracked manifold.  Not everything went swimmingly but due to my slow, careful and methodical approach to the task, with the help of the forum I completed the job and felt confident that everything has been completed as it should. On first start attempt, the battery gave out after 5 seconds as the car hadnt been on a run for a week with doors open quite often, etc.... So I jumped it off another car and it sprang to life and ran at idle very sweetly. The 4x4 transmission light had come on after the initial failed start attempt but extinguished on the second start. No fumes, no misfire, so proceed to a test drive upon which, within the first couple hundred gentle yards, I noticed some heavy black smoke from the rear (so did a few other road users...oops). When the smoke cleared up I gave it a bit more welly but noticed a dramatic lack of power. So, The power loss is lineal, I can hear a correct slight turbo whistle, there is no eml , egr is disconnected, the zorst is running clean and from tonights research, I am pretty confused. I have been exceptionally carefull with every component removed and the only question I asked my self was if, a: was the pipe to the black plastic turbo pressure chamber loose before the job started (I reconnected it after as I saw it hanging loose) and b: whilst the rocker cover was off, it sat upside down on the bench overnight so could oil residue have run somewhere it ought not?  Other wise, comments of vacuum pipes, under fueling, maf sensor, etc are all mentioned but I think that this is unlikely unless they are prone to failure from the jump cable start up. Any ideas appreciated.  Thanks.

[SLX530]

Anyone experienced a blocked cat or dpf on one of these. Thinking that the heavy smoke and soot may have brought on a partial blockage. All help appreciated as I'm stumped.

[X5Sport]

No DPF to worry about on the E53. Never heard of a blocked cat.  The usual suspect is a leak in the turbo system giving a lack of boost together with over fuelling.  The turbo may spool up, but not generate enough boost pressure.

[SLX530]

Would that generate an EML? Is there a probable culprit after the job carried out because I was in no way ham fisted during the repair. Could it just be a split OE vacuum hose? Thanks.

[X5Sport]

It doesn't usually trigger a light, based upon what others have reported.

It could indeed be nothing more than a split, and very likely bad coincidental timing!

[SLX530]

So my problems were down to a coincidental vacuum pipe issue.  The pipe from the vacuum tank to the intersection on the opposite side of the engine was rotten just before the connection and the two small pipes to the other regulators had collapsed.  Power has been restored for the princely sum of £4. Thanks for your help. 

[grumpywurzel]

awesome mate, another one back on the road