Freelander injection pump

This is too hit and miss to be reliable. It's exactly the reason why the pump should be timed (by a specialist) and locked before fitting. The pulley is then fitted in it's correct position as dictated by it's locking pin.

flywheel was locked, pump was locked (total recon pump), pump sprocket pinned! just cant understand the hunting idle????? actually on the road, it pulls better than it ever has

If your pump has come from a diesel specialist then I would be reluctant to rotate the pulley on the pump shaft.

Could be a sensor issue. Maybe an air leak after the MAF.
Try unplugging the MAF.

Chaser said:

This is too hit and miss to be reliable. It's exactly the reason why the pump should be timed (by a specialist) and locked before fitting. The pulley is then fitted in it's correct position as dictated by it's locking pin.

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When you fit a pump that has been timed up, you may still have to adjust it to get the timing spot on.
I agree that it should be timed by a specialist once fitted because timing it as I said (moving the pulley) is a crude way of doing it. But if he was going it alone with no equipment, then this was maybe a way to get the engine running a bit sweeter.

I understand where your coming from mtech but in reality there is no intended adjustment once fitted to the engine, accurate adjustment having already been achieved and locked by specialist equipment.

Chaser said:

If your pump has come from a diesel specialist then I would be reluctant to rotate the pulley on the pump shaft.

Could be a sensor issue. Maybe an air leak after the MAF.
Try unplugging the MAF.

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pump has come from an ex xpart dealership, so pretty sure pump is a-ok, air leak after maf could be it, i didnt replace gaskets on egr, or inlet to inlet manifold! BUT would this cause hunting??

ste220 said:

pump has come from an ex xpart dealership, so pretty sure pump is a-ok, air leak after maf could be it, i didnt replace gaskets on egr, or inlet to inlet manifold! BUT would this cause hunting??

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Any unmetered air is likely to upset the idle if the ECU is trying to compensate for what it sees as less then optimum air/fuel ratio.
It's difficult to say if this would be noticeable though.

How did the engine idle before the pump swap?

perfectly

ste220 said:

perfectly

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Kinda stating the obvious I know but recheck everything you've done...

I would still put my money on the pump timing. I have had so many pumps from Diesel specialists and they only need to be 1 degree out and they will hunt, smoke, pink.
I had 1 highly regarded diesel specialist tell me that a pump couldn’t fail on 2 cylinders and wanted to send it back as ok.
I put a new pump on and it ran sweet. The old one ran on 2 cylinders. Every time I fit a pump I look at the dynamic timing and it is always out.
When tensioning the belt on the pump end you load the pulley up with 25nm in an anticlockwise direction and then tighten the 4 bolts up in the elongated slots. This is where the error of 1 or 2 degrees can occur.
Going off on a tangent it’s the same when you time the VW pumps. You can get it absolutely spot on with a DTI gauge yet when you run it up and put your kit on it the dynamic timing is 2-3 degrees out.
The problem is until it is connected up to diagnostic equipment it is all guess work.

the only thing is, that the l-series compensates itself to slight timing variations doesnt it????

No, the system isn’t that clever. The start of injection has got to be spot on. Modern HDI systems will retard or advance through the electronic injection duration but with this one, once it’s set that’s it.
It’s a bit like a petrol distributor. The vacuum advance will advance the ignition from a set point. So if the advance is 15 degrees and your ignition is set at 5 degrees then you will get 20 degrees advance.
If your ignition was set at 10 degrees then you will have 25 degrees advanced. The engine will pink and the ecu can’t adjust it. It tries to meter the fuel and the idle air valve goes nuts trying to compensate but there’s nothing it can do about the timing.

ok! BUT my pump/flywheel and everything else that needed to be, was pinned, SO it SHOULD BE spot on! are you saying that even pinned it can be out?????? my head is starting to hurt now, OR could it be as simple as an air leak????

If belt tensioning is correctly carried out with the timing pins in place it will not affect the pump timing.

I agree that when fitting a pump supplied timed and locked that it will only be as good as the 'specialist' that timed it. That said they will be aware of importance of being accurate.

Variations from this initial setting are indeed controlled by the ECU as it responds to sensor inputs.

I guess the question is do you trust your pump supplier?

Sorry missed your post there:

I guess the question is do you trust your pump supplier? - Totaly agree, this is what it all boils down to.

In response to ste220 post:

No but what I am saying is there is always going to be a difference between static and dynamic timing.
I haven’t had many where they have been perfect, first go. If it has been a brand new pump then yes it is spot on but second hand and recon, no

ste220, why did you need to change the pump?

on constant throttle for ~10seconds, the mil light comes on, then goes off when you let the throttle off! diagnostics came up with injection timing neg deviation. basically the deviation solenoid in the pump was fecked and was cheaper to just replace the pump!

Well I think I would recheck everything that has been disturbed to eliminate your work, have the codes read again and depending on the result you may have to contact the pump supplier for their opinion.

it isnt throwing any faults now though, runs spot on when actually driving, just hunts at idle

does it stabilise with the MAF disconnected?