Bad acceleration on 1998 Audi 1.9tdi

[thumpersloper]

I wonder if anyone can help me please. My 1998 Audi 1.9tdi estate has become very poor on acceleration of late. I have changed all filters and bled the fuel system.

Symptoms are :- As you build up speed in each gear and the revs rise it gets to a point where it just stops accelerating as if its holding back. If I turn the ignition off for a couple of seconds and then back on again power is restored for a short while. Also it has just started momenterily reving itself when starting up after standing for a while. I turn the key and it fires and revs itself then settles to a tickover. When it does this, a puff of black diesel smoke ca be seen and burnt diesel can be smelt.

Has anyone any ideas what the problem could be??? Could it be an engine sensor or the turbo failing??? Its done 190,000 miles but doesn't use much oil nor does it smoke.

[Justin S]

Usual fail are the MAF sensors. Try that and see what happends.............

[mk2 24v]

MAFs dont usually cause the idling problem and the smoking tho

if you can, get it plugged into a diagnostic tool and see what fault codes it brings up

[ed_crouch]

Possibly MAP sensor ( manifold absolute pressure) or hole in pressure feed line.

[Incorrigible]

Dodgy turbo ? air leak in the intercooler loop ?

black smoke is probably unburnt fuel, I would suspect not enough air, or has been mentioned before bad metering

FWIW I've seen the IC loop hard pipe and the IC itself go on these (under the drivers side headlamp IIRC)

[BoraBora]

if its revving itself and theres black smoke pouring out the back this sounds like turbo bearings failing, if it runs away on oil, this is the end of your engine (unless you put it into 5th gear and slap the clutch up)

try other things first www.tdiclub.com is a good place to troubleshoot these engines lots of guru's on there.

[celcius]

Turbo vanes coked up