Hi folks,
Working on a 2.5 just now that stalls easily setting off in first-high. Nanocom shows modulation up at 95% so I'm guessing the pump static timing needs a wee tweak?
Does that sound about right, or am I holding the wrong end of the stick?
I've seen mention online of people tweaking the pump position whilst watching nanocom, anyone tried that?
Ta.
I have just dug out an old scan of my engine a few years ago and it was showing 76.05% when idling at 750 rpm.
Rotating the pump to bring the timing back is usually trial and error by ear. A guy called Rousecapri was the guy who had done quite a few, but not sure if he is a member on here. He was on Rangerovers.net.
Using Nanacom or Faultmate would be more accurate I guess. I personnally would not like to run the engine with a loose pump.
Stop the engine, move the pump then retighten it. Run the engine again and recheck readings.
The position of the top section of the body can also have an effect. If it has been disturbed it may need moving towards the back of the engine a smidge. But only a smidge as it is quite sensative. If you move it too far back you will find that the revs hang on the over-run.
Cheers, will have a look at that this week hopefully.
mace wrote:
Hi folks,
Working on a 2.5 just now that stalls easily setting off in first-high. Nanocom shows modulation up at 95% so I'm guessing the pump static timing needs a wee tweak?
Does that sound about right, or am I holding the wrong end of the stick?
I've seen mention online of people tweaking the pump position whilst watching nanocom, anyone tried that?
Ta.
Hi Miah,
I just a few weeks ago swapped out my top and middle gaskets on the FIP and after asking Wammers on another forum (he is a retired mechanic and a serious FIP boffin - but he is cantankerous hahaha) the advice I got was this:-
Modulation is only adjustable via static timing and no other way. 95% is right at the end of the ability for the electronic brains to account for chain stretch and it will need the static timing adjusting sooner rather than later. My modulation is 67% but I will do static timing in the spring.
Twisting the pump only changes the mg/stroke (which is really mg/litre apparently) which should be between 5 - 6 mg/str for best running @ 750rpm, 128 is the correct fuelling value on Nanocom. To keep my rpm @ 750 I have to put my fuelling at 129 so you can adjust that. The dash rpm counter needle however shows around 775 on the dash, Nano shows 750rpm exactly, so I go with that.
If you haven't yet done it, the twisting and moving is a pain in the arse and will seriously test your patience! Slight tightening of one bolt revs go up, slight loosening of another and they drop, it's a balancing act it just takes time and cups of tea :) If you loosen the bolts too much if you don't spot it you will find a nice diesel smell, thats the pump pissing diesel out - so don't loosen them too much just enough to get movement.
I am in no way a guru I'm just passing on the same info that I was given so I hope this will help others as it did for me.
So correct measurements should be:
750rpm
fuelling @ 128 on nanocom
5-6 mg/str
modulation 50% (+/- 5%)
With new chains static timing is set at 0.95 mm lift at TDC. Over time as the chains run in and loosen up slightly it should drop to 0.9 mm static.
Hi Hoppy,
Cheers for that. So, based on what you've said there, I'd be wasting my time trying to tweak the rotational position of the pump - it needs static timed?
Thanks,
Miah
From what I'm told yes. Twisting alters the amount of fuel being delivered (and revs go up and down as you'd find out) and if you check Nano if you have around 2-3 mg/str then your car will go like a race car off the line - mine did! But it started to stall and judder. That's when I read up and asked for advice. I was told static timing is the base line to work from and you can dial out the chain stretch (up to a point I should imagine) then once that's done, then twisting would need to be done to bring the mg/str back to the right readings.
I'm only going from what I've been told but it will be Spring before I sort out the static timing
hope that helps,
Hoppy