View Full Version : Help understanding injector timing data

13-05-2009, 08:52 AM
My friend has a 2001 TDi (115BHP AUY engine) that is rattles at tick over but fine when driving, it returns good MPG and it doesn't use any fluids.

I put it on VAG.COM and discovered the start of inj. is 6.1 BTDC at idle and it should be within 1 BTDC to 2 ATDC, as you rev the engine up it backs of to about 9 BTDC. I have the same engine is a 2002 Galaxy that is running fine, that idles at 0.8 ATDC and backs of to about 9 BTDC when reved up.

Sounds to me like the injector timing on the belt is out but I am no expert, what do you guys think.........

Oh and if I could be cheeky and ask 1 other thing. His specified and actual MAF readings are both about 250 at idle but my actual is way up at about 490, I haven't noticed a problems with performance but is my MAF about to give up on me?

Thanks you very much for reading and hopefully replying.

Anthony Bigwood
01-07-2009, 12:46 AM
Hi. Im afraid I dont have the answer but do appear to have the same problem on a 2000 1.9 TDI Sharan 110 Sport AUY Engine. At idle (903RPM) the car shakes and lacks power when driving. Its as though the engine is running on 3 cylinders. VagCom is showing almost the same readings as you Injection start at around 5 degrees BTDC as well as MAF readings in excess of tollerances. I too am thinking injection timing but am uncertain how to adjust (not like T4 ACV injection pump with its own timing belt which would not even start if there was a couple of degrees error but was easily adjustable with the help of VagCom) I am thinking I need to go through a cambelt set up as this is the only way I can see to alter the timing.
Any comments gladly recd.

01-07-2009, 09:25 PM
how about doing a full scan and posting it on here.
is this the PD engine if so check the wireing to the injectors
as the car had any work done on it
if you say it smoothes out when the revs are picked up it could be the timing belt as gone slack check that out
try cleaning the throttle body out then doing a throttle body alinement

if you got 2 tdi engines how about swapping the mafs to see what happens (only do this on your own back as its only a suggestion i dont want to be held responable if it go's wrong)
hth paul