Bloody modulation

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Flossie

Flossie

Well-Known Member
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Location
Shropshire
Needs to be 50% +/- 5. I've got it to 51% coolent at 95 Deg, idling quite smooth although I've never heard another to compare it to.
Started her up from cold and left to idle it runs very lumpy, mod is 35% at 13 Deg, it runs lumpy (possibly dropping on to 5 cylinders, dunno) but gets slightly better as the coolent temp rises but not until it gets to 85 Deg, at 90 to 95 degs it runs smooth
. Things to note, all glow plugs work well, fuel heater is working according to nanocom , 36 Deg fuel at 95 Deg coolent. Idle switches between 728 and 750 on the nano, this happens every 5 secs roughly when cold but longer intervals when hot.
Should say, modulation was 80 something degrees and running bad when I first got her, running much better now but still not good enough.
How do you increase the idle using nanocom? Can't figure it out. It's on 128 which should be correct .
Quick! Me MOT is this Thursday!
 
Flossie said:
Needs to be 50% +/- 5. I've got it to 51% coolent at 95 Deg, idling quite smooth although I've never heard another to compare it to.
Started her up from cold and left to idle it runs very lumpy, mod is 35% at 13 Deg, it runs lumpy (possibly dropping on to 5 cylinders, dunno) but gets slightly better as the coolent temp rises but not until it gets to 85 Deg, at 90 to 95 degs it runs smooth
. Things to note, all glow plugs work well, fuel heater is working according to nanocom , 36 Deg fuel at 95 Deg coolent. Idle switches between 728 and 750 on the nano, this happens every 5 secs roughly when cold but longer intervals when hot.
Should say, modulation was 80 something degrees and running bad when I first got her, running much better now but still not good enough.
How do you increase the idle using nanocom? Can't figure it out. It's on 128 which should be correct .
Quick! Me MOT is this Thursday!
Click to expand...
You will never get closer than 51% at 95C. You could try increasing the idle rpm, it should not drop below 750, increase 128 to 130.
 
Last edited:
Flossie said:
How do I do that though? Can't find anything on nano that I can change..
Click to expand...
I do not know the Nano, but on Faultmate there is a screen with a line of numbers across the screen each in a box. The first number controls the idle speed, often but not always it's 128. That number can be changed and written back, with the engine running you will notice an immediate small increase in rpm.
LZ will not let me upload a photo, seems to be a regular problem
 
P38 1.jpg
 

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Flossie said:
Needs to be 50% +/- 5. I've got it to 51% coolent at 95 Deg, idling quite smooth although I've never heard another to compare it to.
Started her up from cold and left to idle it runs very lumpy, mod is 35% at 13 Deg, it runs lumpy (possibly dropping on to 5 cylinders, dunno) but gets slightly better as the coolent temp rises but not until it gets to 85 Deg, at 90 to 95 degs it runs smooth
. Things to note, all glow plugs work well, fuel heater is working according to nanocom , 36 Deg fuel at 95 Deg coolent. Idle switches between 728 and 750 on the nano, this happens every 5 secs roughly when cold but longer intervals when hot.
Should say, modulation was 80 something degrees and running bad when I first got her, running much better now but still not good enough.
How do you increase the idle using nanocom? Can't figure it out. It's on 128 which should be correct .
Quick! Me MOT is this Thursday!
Click to expand...

It should idle at 750rpm but it will drop briefly when the A/C or another load kicks in before the electronics stabilises it again. I wonder why it improves with temperature? Why would that affect anything? Worn FIP? Can you record a trace of the EDC fuelling from the Nanocom when it is up to temperature?
 
Grrrrrr said:
It should idle at 750rpm but it will drop briefly when the A/C or another load kicks in before the electronics stabilises it again. I wonder why it improves with temperature? Why would that affect anything? Worn FIP? Can you record a trace of the EDC fuelling from the Nanocom when it is up to temperature?
Click to expand...
Dunno, that's why I'm here.
Thought maybe that thing on the FIP wants moving a tad, read loads of posts with similar problems but never really a conclusion .
Redex and a good booting is worth a try, just hoping it isn't a knackered FIP or injectors. I'll note some fuelling figures tomorrow but it'll be pen and paper, only got a phone.
 
I read a post, think it was wammers bus, where he upped the 128 to 129 I thing, to get a 750rpm idle.
Mines more 728rpm than 750 when cold but this does improve as it gets hotter but still swopping between the two fiquires even when at 95 Deg just not as often. The 728 rpm seems to correspond with the lumpy running but I suspect there is a delay between the engine revs and nano reading.
 
Flossie said:
I read a post, think it was wammers bus, where he upped the 128 to 129 I thing, to get a 750rpm idle.
Mines more 728rpm than 750 when cold but this does improve as it gets hotter but still swopping between the two fiquires even when at 95 Deg just not as often. The 728 rpm seems to correspond with the lumpy running but I suspect there is a delay between the engine revs and nano reading.
Click to expand...
DO NOT fiddle with the top of the FIP, I doubt that is the problem. With Faultmate, I can just move the cursor to the box and change the number, I'm sure you should be able to do the same with Nanocom. As the modulation was at 80%, the timing chains must be worn. If the chain tensioners are worn, it may be that the chains are slack causing a problem. My first step would be to up the idle speed a little. I would also look closely at the crank sensor signal and the connector.
 
Figured out the idle, touch screen press point was off sync, nano is a bit like that. Increased from 128 to 130 which has upped it about 50rpm. The idle fluctuates still. I've done a 6 minute video showing things but forgot to press record until it had been running a while. I've revved it up occasionally, revs are sluggish to return and the idle dips below 750 until it 'catches' itself.
When it's cooled down I'll get some more data of other stuff.
Edit- bloody video won't upload:mad:!!
 
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