2.5 tdi BAU - is my timing too retarded ?

[quattrodave]

Been checking the car over now and decided to check the injection timing is ok after a recent belt change.
So in basic settings group 4 I have -
835 RPM, coolant at 93.5 deg.
Early = 14.8 to 15 deg, cold start 25.4% to 27%
Late = 0.2 to 0.8 deg, cold start 100.2% (no fluctuation)
The reason for checking is to try to find the reason for overall fuel consumtion of 23MPG (based on a bit of urban, A roads and motorway all at sensible speeds driving like granny !)
Cold and hot starts are perfect, slight smoke at cold and sounds a little rough until it warms slightly (but never misfires)
'53 plate quattro auto tip 170k miles by the way
Thanks in advance

 

[Mike B]

Don't know about settings but clearly still not right mpg.Didnt the timing get sorted when the belt was done?I have seen it done and not quick and easy

 

[quattrodave]

Hi Mike, the belt was done before I bought the car so I'm just checking the timing is within spec.
Looking on the 'net it seems to be OK, I'm just wondering if advancing it a tad will help the MPG as it seems at the lower end of the scale.
Boost and MAF logs next I guess......

 

[Mike B]

I wouldn't touch the timing unless it is clearly out.Mine was by about 1.5 cogs I was told cos it was botched previously and it still ran OK but was a poor starter when hot.The mpg could be other things .Have you had a diagnostics check?

 

[quattrodave]

Yes I've checked for faults, only one was a dodgy engine mount, new Hitachi MAF just fitted as well.

 

[S4_dan]

I don't have poor MPG QuattroDave, just a massive flat spot with no torque or power until 2k rpm then it's off.

My timing is at 2.2 ATDC I think the spec is 2 with +/- 1.5, so all within spec.

Dan

 

[quattrodave]

Hi Dan,
Mines at the lower end of OK, around 0.5 deg ATDC. What's your MPG by the way, 23MPG out of mine is pretty poor even taking into consideration the auto box, I would expect around 30 overall at least for mixed driving (hopefully !)
Mine also has a flat spot up to around 1800rpm, but the auto box doesn't help that either !

 

[S4_dan]

I'm getting around 36 mixed and 44 long runs at the moment. I was getting 49 on long runs when I bought the car at the back end of summer last year! (With MAF disconnected then mind)

My flat spot is worse when I have the EGR connected, there is no acceleration for a second or so after each gear change....nothing, then slowly picks up. Really annoying! So I've have unplugged the EGR vacuum pipe and blocked it and left the EGR intact (No blanking plates or anything) Howver, I did reconnect it for the graphs I did in case it would show something up.

Dan

 

[quattrodave]

thanks for that
Did you have any fault lights on with the egr disconnected ?
I tried it on mine but the emmision warning light came on within a mile

 

[S4_dan]

No, I don't have any warning lights on. Mine is a 2002. I think my EGR might be stuck open a little. Need to clean it out properly and check again.

 

[Mike B]

You will be doing well Dave to get 30 overall out of the auto unless it includes some good long runs .The manual can do much more cos you can hold back the revs and use all the torque.Perhaps my tuning box is more effective than I thought shame we are not close enough to try it on yours.Certainly no flat spots and I have been pleased with the results when I tried getting a move on a few times recently .

 

[quattrodave]

To be honest mike, anything over 23 mpg would be great !
If there's nothing wrong I'll accept it but that's the thing with vcds, you just keep on digging around...........

 

[Mike B]

If you still plan to get the belts done again I would fix a visit to London as I did .He is the man who could sort things as he did mine and if he then drove yours round the streets on a quiet bank hol mon like he did mine I think you would be impressed.

 

[quattrodave]

I can't really justify doing the belts yet, they were done at 150k two years ago, currently on 170k so a few years off yet

 

[Mike B]

Same here but wasn't happy with the car and it was either that or put up with things .Probably why the previous owner sold and never understood why the first owner got the job botched to save money.Lovely car which deserved better bit like my rescue dog

 

[quattrodave]

Fair point, I'll get some logs done at the weekend and post them up. Hopefully something will show up