Thread: 300tdi running a bit rough after engine rebuild??

The cam really can't be out though, the flywheel was locked the whole time with the locking pin and when the belt was all done I could see that the cam was aligned because I had the radiator out to do the rebuild.
I did have the camshaft cog off to replace the seal but that can only go back on one way so should be fine.
And I thought the purpose of the pump locking pin was to keep the pump timing right before taking the belt off??
Please correct me if I am wrong about any of this.

Thanks flipper for the offer, a step by step guide to the way that you do it all would be great I'll PM you soon.

The one way to be certain that your timing is spot on is if plunger lift is at 1,54mm at TDC
To access plunger remove the cap in centre of four injector unions on IP
Use dial guage to then measure forward displacement of the plunger as engine rotates.
At TDC the lift (forward discplacement) should be 1.54mm - it is rumoured / speculated that 1,60mm of lift will give a bit more advance and bite.
All other methods of lining up marks etc etc wil have a certain degree of error.
Actual plunger lift will accurately set your timing.

S

Originally Posted by Defendozer

The cam really can't be out though, the flywheel was locked the whole time with the locking pin and when the belt was all done I could see that the cam was aligned because I had the radiator out to do the rebuild.
I did have the camshaft cog off to replace the seal but that can only go back on one way so should be fine.
And I thought the purpose of the pump locking pin was to keep the pump timing right before taking the belt off??
Please correct me if I am wrong about any of this.

Thanks flipper for the offer, a step by step guide to the way that you do it all would be great I'll PM you soon.

That's correct, the pins lock the pump & crank but the cam is not locked which can move slightly when pulling the belt over so its good to keep a keen eye on it.

As you said the cam gear is keyed to the shaft so it does only go on one way.

All the times I have changed a 300tdi belt I have just slackened the 3 pump pulley bolts while the pins are in to get the belt on, then tension the belt, followed by doing up the 3 bolts on the pump pulley,check marks are still all good, take the pins out & rotate the crank twice, check the marks are aligned & pump pin slides in-out nicely, lock the pins in & re-tension the belt but don't let the belt go completely slack when undoing the tensioner just slightly let off some tension & re-torque. Once again make sure the pin for the pump slides nicely in & out, take pins out, rotate the crank twice again & re-check marks & pump pin slides nice again.

If all is okay put her back together

Originally Posted by Defendozer

The crankshaft and camshaft are spot on for timing and I'm 100% sure of that cause the flywheel was locked and the cam pulley was exactly right when I put the new belt in, the fuel pump cog can't be a tooth out either really to be honest because it was locked with a pin the whole time and I loosened the three bolts to get the belt on and to tension it.

you did what now?

Once I tensioned the belt I did the three bolts back up to spec whilst making sure that the locking pin was in the correct position,
I then turned the crank for two revolutions of the belt, put the locking pins back in (they all lined up) and re-tensioned it.

An update for you now though, I got the time yesterday to recheck the timing and valves, one of the valves was 2 thou over and another two were a bit tight, how much difference would that make to the running of the engine?

I also found that the fuel pump timing WAS a little bit out, no idea how though as it was spot on when I did it!! Oh well I must have missed something

But yeah the pin didn't properly go the whole way in so I once more loosened the three bolts and put a 22mm ring spanner on the nut in the middle and turned the pump a little till the pin lined up nicely and then all back together again.

Turned it over and hey wasn't the difference noticeable, fired straight up and ran like a dream Have been driving it today and it seems to be like new so I'm stoked

Thanks soooo much to you all, your time and advice is most appreciated

Honestly, owning a Landrover is one of the best things ever, so many helpful friendly people and lessons and skills learn't along the way are invaluable!

Thanks again, Remo

Good to hear you sorted it defendozer.

Did the adjustment of the fuel pump timing get rid of the tapping noise?

your loosening of the bolts to put the belt on is how it got out . That is not the way to do it . Just have a think about how that is possible and you will understand.
Cheers Scott

Whats happened is the 3 locking bolts that set the cam gear to drive plate have been undone. Depending on which pump setup you have (remembering that this pump is used in a few different engines with different drive configurations) either the drive gear or the drive plate has a large slot in it that the timing pin fits through and the other of the drive gear or drive plate has the closer tolerance hole to hold the pump in position.

with the one item held fast by the pin if you loosen off the 3 locking bolts that mount the 2 together the drive part with the larger tolerance for the timing pin clearance is free to rotate and will do so quite easily.

Remember the timing pin is really there to get the coarse timing of the injector pump to the cam and crank and right off the top of my head gives you a tolerance of about 8 degrees per tooth, thats on the pump which is turning at half crank speed so its 16ish degrees of crank per tooth on the pump.