Horrible MPG after timing belt change

Hello all,
Recently had my usual lr mechanic replace the timing belt on my 200tdi daily drive as it was overdue changing by several 100 miles at the time and I just couldn't afford the time to do it on account of work obligations.
First thing I noticed when I got the car back was that it was far less noisier than it used to be.... the usual 'clattering' noise of combustion I had gotten used to had been significantly reduced. I assumed that meant the engine was happier with the new belt in until I observed I was using way more fuel than I used to do on my daily commute (about 2 liters more) and it was running slightly hotter than usual.
Spoke to the mechanic and he assumes this could be on account of the injection timing being slightly retarded.
Would just like to know if indeed that is the case (if injection timing could be the only reason for such poor mileage) and how much advance should I dial in to get it running right.

ifloochies said:

Hello all,
Recently had my usual lr mechanic replace the timing belt on my 200tdi daily drive as it was overdue changing by several 100 miles at the time and I just couldn't afford the time to do it on account of work obligations.
First thing I noticed when I got the car back was that it was far less noisier than it used to be.... the usual 'clattering' noise of combustion I had gotten used to had been significantly reduced. I assumed that meant the engine was happier with the new belt in until I observed I was using way more fuel than I used to do on my daily commute (about 2 liters more) and it was running slightly hotter than usual.
Spoke to the mechanic and he assumes this could be on account of the injection timing being slightly retarded.
Would just like to know if indeed that is the case (if injection timing could be the only reason for such poor mileage) and how much advance should I dial in to get it running right.

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Seeing how he put the belt on and set the pump timing then I think he should do it FOC

sounds retarded , it should be advanced till it knocks then just back enough till knock just goes , i use drill bits of various sizes so youve something to hold pump against whilst you retighten the 3 bolts and you are advancing in known measured amounts

landowner said:

Seeing how he put the belt on and set the pump timing then I think he should do it FOC

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Yeah, sounds like the logical thing to do but really don't know when I can find the time to take the car back to him.
Thing is, been reading up on subject the past couple of days and I've found out that advancing or retarding timing on the pump is relatively easy to do through the small access hole in the timing belt cover.... would just like to know just how much advance will do the trick before I have a go at it at work.

jamesmartin said:

sounds retarded , it should be advanced till it knocks then just back enough till knock just goes , i use drill bits of various sizes so youve something to hold pump against whilst you retighten the 3 bolts and you are advancing in known measured amounts

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Just seen this....
So if I'm not mistaken, full advance as far as the pump will go with the timing pin in place, back down a bit from there, re torque the bolts, run engine and listen for knocking and repeat process until knocking goes away.
Just wondering though, are there marks on the pump drive to look for as a reference?

try it with pin fully pushed in to pump slacken the 3 bolts then turn pump nut clockwise against pin hold whilst you tighten the 3 bolts , if its not enough use a 9mm drill bit as the pin the go smaller each time holding pump clockwise against pin before tightening the 3 bolts repeat till engine knocks then back till it doesnt

Thats all assuming he hasnt fitted the belt right over one way so theres no way to advance it without stripping it down!
Of course Ive never done that you understand cough cough

very true

Advancing the timing is easy to do, so easy even I did it. Yes remove the access plate, making sure the engine is at TDC and that the pump is lined up. I used a 9mm drill bit. There is a nice video on you tube about it. Just google it and watch the one from trailfitters toolbox (no affiliation). He shows you how to set the timing but it is the same process for advancing it. Should take less than an hour.

Oh and you are describing my exact issue which is why I advanced the timing when I did the timing belt change. Fixed engine and EGT temps straight away.

So I had a go at sorting it this afternoon.
Lynall, you were right mate, I slackened the three bolts and there was no more room for advance
To let you know just how bad the timing was out, I retarded slightly from where it was in its "fully advanced" point and it wouldn't start.
Had to sacrifice my lunch break +1 hour taking things off to get to the belt
Slackened the tensioner and moved the cog/pump drive ahead by two teeth on the belt before I got the required clearance for advance.
Started it with the front pulley back on with the bolt in place but with the belt cover off just to be sure I was on the right track.
Fired up loud as a tractor from my new position at full advance.
James Martin, I backed it down a touch per your recommendation to the point where it knocks that brief moment before it kicks into life but does not knock whiles running.
Do you reckon that's just about it or do I need to back it down a bit more?
And just so I know, what is the effect of too much advance on these engines?
So far with what I did today, throttle response seems to have improved and the autobox isn't kicking down as much as it was doing just to keep up the momentum around town but I need to know I'm not stressing the engine out or anything of the sort.

if its too advanced knock will sound uncomfortable, just before that knock is optimum engine running

jamesmartin said:

if its too advanced knock will sound uncomfortable, just before that knock is optimum engine running

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Then I think its safe to say I got it right....
Sounds a bit angry when I mash down the pedal but certainly no knock and pulls much much better.
Just want to pick your brains on one last issue that I've learnt to live with the past year or so but wouldn't mind having it resolved all the same.
When started from cold, it idles flat as it should, rev it up and it would come down to idle after I let go of the pedal. After less than 5 minutes when it starts to warm up, rev it up and it would stick at about 1000 to 1200rpm until the engine is loaded by shifting into D or R, turning the AC on or by turning the wheel to full lock so the power steering pump loads the engine and starts to whine a bit.
So far checked for any kinks in the throttle cable but it still does it even with the cable disconnected. Checked for any backpressure in the fuel return line by removing it with the engine running and having it drain into a catch pan but still had the same issue so just gave up on it and have been managing it till now. Does get on my nerves though when sitting in traffic and have the transmission in N. Any advice on this?

Have a read here, bit anal and in depth, loads more articles on the net, sounds to me like internal fault on pump, but theres so many outside parameters that can effect it you will need to read and then check everything that catches your eye.
Bosch Ve Pumps
There is a cold start function built in the pump and Im not sure if this increases rpm or fuelling
Ps I never touch the throttle when starting, just flick the key and go.

pump is normally advanced for cold start ,throttle cable adjusts govenor so not direct like butterfly in a carb, you may have worn and sticking parts in pump

Why not invest in the timing pin kit? £33 on EBAY. I've had mine for years and used it countless times on different vehicles. You have (apart from other useful stuff) the flywheel locking pin and the pump locking pin which makes the job simple and perfectly accurate every time.

the banjo where the return line connects to pump has a restricted bore check it is clean.

Blackburn said:

the banjo where the return line connects to pump has a restricted bore check it is clean.

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Already ruled that one out...
When it first started playing up, I read somewhere that a restriction in the fuel return causes similar problems so that was one of the first areas I tackled.
As JamesMartin stated, the thought did occur to me also that it could be some sort of problem with the pump so I sort of let it be.... I reckon I ought to start looking for a replacement pump.

Should the belt not be removed and re-fitted in the correct postion...sounds like its one or more teeth out to me....

Nick.

As Nick says worth checking timing correct before expense of pump refurb