Land Rover Td5 cylinder balance

[Audiman]

Thing is most people would just leave it be and be happy with what they have. You are not happy so your options are start spending or become happy.

I’m not quite sure what you are expecting the forum to come up with? Cheapest way to proceed is do nothing. If that’s not an option then find someone who will test the injectors correctly.

It will get pricey after that.

 

[bismillah]

Thing is most people would just leave it be and be happy with what they have. You are not happy so your options are start spending or become happy.

I’m not quite sure what you are expecting the forum to come up with? Cheapest way to proceed is do nothing. If that’s not an option then find someone who will test the injectors correctly.

It will get pricey after that.

my intention is to have an engine that works as it should, we are all lovers of mechanics and it is normal that it is satisfactory to have a car that is mechanically in order.

I don't make it a disease, the reason I talk about it here is to compare myself with certainly more expert people and try to waste as little money as possible, first of all, to understand the cause and than effectively evaluate whether the intervention to resolve it is worth it or less. that's all.

 

[JHZR2]

Of course, I didn't venture to open any injectors....

When I talk about injector clearance, I'm talking about this:

www.discovery2.co.uk / TD5 Engine - Injector Seal Replacement

Take the rocker cover off.
You wll see the rockers and shaft that push down the injectors.
You need to get each injector on its full down stroke (cam lobe fully up ).
To do this you can either turn the crank nut, or rock the car, in gear, untill the cam lobe is up.
Now, when then injector is fully compressed, slacken off the adjuster lock nut and, with a flat screwdriver, turn the adjuster screw " in " untill you feel resistance. This is the injector, " bottoming out ".
Once youve done this, you just turn the screw back ONE FULL TURN, and lock it back off.
Repeat for all five.

I don’t really have the time to go through the entire link, but it looks an awful lot like how we set valve clearances on the older Mercedes engines. You set the cam lobe to a certain position and adjust it a certain way. If I’m not mistaken, it seems like this is almost a way to set the injector heat shield washer, which I assume is in there between the injector base and the head, and you do it by setting a clearance against the cam.

The only reason I can fathom for the cam to be actuating against the injector is, because somehow it creates some portion of the pulsing action to inject fuel. I would suspect that if you were off by a fraction in terms of the positioning of the injector plunger versus the cam lobes, that it may affect the injector timing by a very small amount. The thing is, it would be consistent, and I’m not entirely sure that I see that the replace injector is consistently off by the same amount. Is it? I can’t imagine that the scanner is giving +13 and -13 values, in terms of degrees past the ideal injection point, but I would suspect the perhaps the electric portion of the injector somehow advances are retards, the mechanical action that the cam is pushing onto the injector body, which intern effects the power poles, and any other sensations that some control system might be optimizing against.

I think if I were you, I would want to remove all of the injectors, and reset them all into place very carefully to ensure that their tightening and positioning are all correct and consistent. Good luck!

 

[dumkid]

if this is like the Volkswagen cam driven injectors, then the cam lobe pushes a pump inside the injector and the electronics control when the injector fires.

 

[bismillah]

the cam squeezes the injector creating pressure and the electric part opens and closes the injection.

the adjustment that is made basically serves to adjust the point of maximum compression that the cam can reach which vice versa could hammer on the injector

 

[Audiman]

same way the VAG PD engines work. Which is why you need a PD injector specialist to test the injectors for you. Must be one in Germany you can use so your not messing around with UK customs.

 

[bismillah]

Hi everyone, I wanted to do a test.
Today together with a friend I removed the third injector (the one bought used) and swapped it with the one in position 1 (the one on the radiator side)

Currently I have this configuration
Position 1: Injector bought used
Position 2: Injector originally 2
Position 3: Injector originally 1
Position 4: Injector originally 4
Position 5: Injector originally 3


These are the nanocom readings in idle

Injector 1: -6 -7 -6 -7 -4- 3- 2- 1 -7 -2 -7 -5 -4 -3 -5 -4 0 -1 1 -1
Injector 2: 1 -1 -1 -5 -3 -9 -7 -7 -8 -1 -4 -3 -4 -6
Injector 3: -1 5 -2 4 -4 1 7 -2-3 1 2 0 -2 1 3 1 2
Injector 4: -2 2 -7 0 2 -2 -3
Injector 5: 1 5 7 6 9 3 12 8 5 11 6 7 6 9 11 8

What do you guys think?

However, I noticed a big improvement, the engine at idle vibrates half as much as before. Efficiency and smoke unchanged (no smoke). Engine definitely vibrates less at idle and when driving at low speed under-torque (not my usual)

How do you think it is possible that by reversing two initectors the engine vibrates much less?
Acoustically there remains a tac tac tac that was not there before the fault....

 

[dumkid]

My guess for why it's smoother is you had two cylinders that fired one after the other that where out of balance, and you moved one of them to a different spot in the firing order, so one or more balanced cylinders fire in between your unbalanced ones.

 

[bismillah]

I thank you for your answer.

I noticed that since the firing order is 1,2,4,5,3 I basically reversed the two injectors that open and close the sequence.

Looking at the numbers though I can't figure out much about which injector(s) are malfunctioning.
Do you by any chance looking at the before and after of swapping the two injectors can you figure anything out?

Thanks