Help Tuning a 2.5na - I dont mean power tuning!!!

Guys

Anyone got any tips for tuning a 2.5na, I don't mean for more power but rather to ensure smooth running etcetera

I have done:
- full service/fluids/filters
- cambelt
- reset tappets

Is there anything else to do like fiddle with injector pump/change glow plugs (takes about 10sec of glows before it will start) etc or are those best left if they are working

Ed

Is this for a Landy, as my 2.5 N/A is not OHC and doesn't have a cambelt

What is your compression like?

Are your injectors OK, with a good spray pattern?

Which injector pump do you have fitted?

flat said:

Guys

Anyone got any tips for tuning a 2.5na, I don't mean for more power but rather to ensure smooth running etcetera

I have done:
- full service/fluids/filters
- cambelt
- reset tappets

Is there anything else to do like fiddle with injector pump/change glow plugs (takes about 10sec of glows before it will start) etc or are those best left if they are working

Ed

Click to expand...

You could tweak your timing.

Mark the pump body and timing chest so you know where the pump sits in relation to the engine. Then you can go back to "as was" if it all goes wrong - but it won't.

You can then rotate the pump slightly to or away from the engine to advance or retart the timing. You will need to set it, then switch it on and rev it a bit listening for clatter, if it sounds OK take it for a road test and see how it feels and drives. Keep doing this till it just feels spot on. I would also do it with the engine warm so that it's set up perfectly at running temp, no point in it running brilliantly at cold then it gets worse as it warms!

Oldseadog said:

Is this for a Landy, as my 2.5 N/A is not OHC and doesn't have a cambelt

Click to expand...

nope my 2.5na is not OHC either but it does have a cambelt that drives the cam that is situated at the side of the block with pushrods for the valves. The injector pump is also driven off the cambelt.

see here
2.5 N/A timing belt replacement. - Land Rover Technical Archive - LR4x4 - The Land Rover Forum

you better check yours!!!

discomania said:

You could tweak your timing.

Mark the pump body and timing chest so you know where the pump sits in relation to the engine. Then you can go back to "as was" if it all goes wrong - but it won't.

You can then rotate the pump slightly to or away from the engine to advance or retart the timing. You will need to set it, then switch it on and rev it a bit listening for clatter, if it sounds OK take it for a road test and see how it feels and drives. Keep doing this till it just feels spot on. I would also do it with the engine warm so that it's set up perfectly at running temp, no point in it running brilliantly at cold then it gets worse as it warms!

Click to expand...

cool, will have a look at this, see what i can do ta

flat said:

nope my 2.5na is not OHC either but it does have a cambelt that drives the cam that is situated at the side of the block with pushrods for the valves. The injector pump is also driven off the cambelt.

see here
2.5 N/A timing belt replacement. - Land Rover Technical Archive - LR4x4 - The Land Rover Forum

you better check yours!!!





cool, will have a look at this, see what i can do ta

Click to expand...

If you get it right you will be impressed (if it's not already good). My 2.5N/A used to run very nicely.

flat said:

nope my 2.5na is not OHC either but it does have a cambelt that drives the cam that is situated at the side of the block with pushrods for the valves. The injector pump is also driven off the cambelt.

see here
2.5 N/A timing belt replacement. - Land Rover Technical Archive - LR4x4 - The Land Rover Forum

you better check yours!!!





cool, will have a look at this, see what i can do ta

Click to expand...

Difference in terminology.

You mentioned a cambelt, which is usually fitted for OHC and then went on to provide a link for 2.5 N/A timing belt replacement!

Me crystal ball ain't working too well at the moment!

Once you have got your timing to a satisfactory stage, then you can adjust the delivery ... but that's another step forward.

Oldseadog said:

You mentioned a cambelt, which is usually fitted for OHC and then went on to provide a link for 2.5 N/A timing belt replacement!

Click to expand...

A cambelt can be fitted regardless of camshaft arrangement.

discomania said:

A cambelt can be fitted regardless of camshaft arrangement.

Click to expand...

Spose it does drive the cam so can be called a cambelt

FN pedants!!

Lol :- D cambelt = timing belt = cambelt

Will tweak the pump, it does run nice but want to check everything. Timing is spot on, everything at neutral ad it were, did the belt very recently and reset everything

Ed

Do you want to tune for economy?

If so, PM me your number and I can talk you through it.

Oldseadog said:

Do you want to tune for economy?

If so, PM me your number and I can talk you through it.

Click to expand...

PM sent, I am on nights till thursady morning so cant really talk at any kind of civilised time until about 1300hrs thurs! Other than that anytime, cheers that brilliant.

I basically want it set up 'just right' timing, tappets, fueling etc all spot on.

Ed

PM received & responded.

cool chat then

Hi all. Couple of question on this.

Do you move the pump with the engine running? Would this allow you to listen to how it runs. Or is it a case of loosen pump, move pump, tighten pump, run engine, adjust, repeat?

I'm curious to know how one identifies "spot on tuning" - is it a bit like focus, i.e. the engine sounds like a bag of spanners either side of the sweet spot?

Also, how much movement of the pump should happen initially. Couple of mm?

Cheers - very useful thread so far.

Thanks,
Dobbs.

Dobbs said:

Hi all. Couple of question on this.

Do you move the pump with the engine running? Would this allow you to listen to how it runs. Or is it a case of loosen pump, move pump, tighten pump, run engine, adjust, repeat?I have always moved the pump with the engine running ... however, I have annealed the pipes first, otherwise they could snap

I'm curious to know how one identifies "spot on tuning" - is it a bit like focus, i.e. the engine sounds like a bag of spanners either side of the sweet spot? that's about it!
Also, how much movement of the pump should happen initially. Couple of mm? you will know as you turn it. It could be a couple of mil or half a mil.

Cheers - very useful thread so far.

Thanks,
Dobbs.

Click to expand...

Hope this helps.

Oldseadog said:

Hope this helps.

Click to expand...

Excellent, yes it does.. thanks.

i am going to crack on with this later on in the week. Hopefully it goes smoothly

I can turn mine quarter of an inch either way and it doesn't alter power much just knocks or black smokes more

Ok i have had a fiddle with this, first set the idle speed to around 850rpm

then i played around with the pump, i can rotate it around 4mm each way without touching the pipes.

turning towards the engine made it sound like a bag of spanners and knock and rotating it out made it sound smoother, rotating it out to far made it smoke a lot.

I settled on around 1.5mm to 2mm pump rotation away from the block.

Took it on a test drive and it feels more lively, but i had lost my top end, it would barely hit 80kmh. So i fiddled with the accelerator linkage (literally fiddled) and the throttle cable and idle again and managed to get my top end back, it will now cruise at 110kmh easy which is around 70mph. It felt like it had more to give but i hit a hill.........

One thing i have noticed today is i can be one gear higher than i was prior, i have done about 60miles of a road and b road and town driving and noticed i am changing gear less - not sure if i really am i need to keep an eye. Seems to be running smoother, although my idle is now around 750 but i am going to leave that alone now

It does smoke a bit, about the same as before, see this video - its poor quality from my phone. This was in 4th gear flat out.

have a look at the rear view mirror - look close. is this normal? How much does everyone else smoke?

My Movie - YouTube

So far happy, well worth doing this. Time will tell if it has improved MPG.

Ed