P38 Diesel occasional cold idle 'missfire' (with Nanacom FIP info)

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Grrrrr - here are the traces done, about two minutes each after a 20 minute drive, all nice and warm, vehichle in Park, no throttle application - with no misfire (that occurs only when partially warmed). 4 files: Fuel with and without AC, Swtiches and General (both with AC). Don't know if any of this reveals much as the idle felt really smooth! Fuel quantity definitely looks higher than the recommended 5-ish from N2O (see earlier posts) which I hope indicates the poor intial off-the-line grunt?

Missfire - awaiting injector socket to swap injector/s out of spare head.

Link to Nanocom traces on Dropbox:
https://www.dropbox.com/sh/2mkiq0635owlv99/AAB3I70lpGzsed3J91O7gKywa?dl=0

Looks fine. Modulation ever so slightly on the high side but that is to be expected and I think yours is the best I've seen. I wouldn't touch that pump with a bargepole!

Pulled your files in Excel for easy viewing. Added some charts and checks.

You've some good advice in the other posts. I'd suggest listening to them!
 

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Grrrrr.... Thank you for your time to view the data and pass on your opinion - which along with the help of Wammers and N2O has caused me to simply deal with the duff injector and leave the pump alone.

I will look at a remap to get the lowdown torque improved.
 
Grrrrr.... Thank you for your time to view the data and pass on your opinion - which along with the help of Wammers and N2O has caused me to simply deal with the duff injector and leave the pump alone.

I will look at a remap to get the lowdown torque improved.

Good only way to do it. Sense prevails. ;);)
 
To quote: yes, you are quite right again dear Wammers!

Despite many conversations on this forum - do you have a 'preferred supplier' for remapping? My ECU is the early one which needs a new 'socket' soldering onto it for a chip to be put into.
 
The plug in boxes work quite well, got one on mine and made a big differance to the power and torque, power box is one make dont go for on of the cheep ones.
 
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To quote: yes, you are quite right again dear Wammers!

Despite many conversations on this forum - do you have a 'preferred supplier' for remapping? My ECU is the early one which needs a new 'socket' soldering onto it for a chip to be put into.

Not really for the internal chip. Mine is internally chipped and goes very well, but it was done when i bought it. So don't know who did it. PSI power boxes have a good rep on here. Make sure you get the one for your year. PSI used to have a web site but can't find it, so for some idea look at this from Paddock. http://www.paddockspares.com/land-rover-performance-parts/tuning/psi-tuning.html
 
We are drifting off topic here a little, however its become an intersting conversation so will continue! I do have a PSI Powerbox - which I took off before all of the above diagnostics whilst looking for the 'miss'. It is really nice, plenty of 2200-3500 action but makes little (if any) difference to that initial off the line punch. However... the one thing I have noticed with it removed is how much smoother the gearshifts are, which sort of ties in with N2O's comment that "Proper remap gives best results, and does not eat gearbox like plug in chips/boxes do"... I'm sure all power increases (or torque increases) will shorten the life of gearboxes, but does a remap retain the 'softer' gearshifts - yours may be a good example as reference Wammers? My 1st-2nd on a gentle throttle (with the PSI box) is noticeably more harsh than with it disconnected (it's a recently fitted Ashcroft ZF -22 box). On full throttle, the changes are better! I've sent an email to Jeremy Fearn to discuss the remap topic and will see what his comments may be. Another chap I've dealt with (BeCM issues!) was Eric Turner of Turner Diganostics - they are offering a remap too with final tuning on a rolling road dynamometer... Whoever can improve the lowdown grunt is likely to get the dosh as I think everybody promises +/-30% midrange improvements.
 
We are drifting off topic here a little, however its become an intersting conversation so will continue! I do have a PSI Powerbox - which I took off before all of the above diagnostics whilst looking for the 'miss'. It is really nice, plenty of 2200-3500 action but makes little (if any) difference to that initial off the line punch. However... the one thing I have noticed with it removed is how much smoother the gearshifts are, which sort of ties in with N2O's comment that "Proper remap gives best results, and does not eat gearbox like plug in chips/boxes do"... I'm sure all power increases (or torque increases) will shorten the life of gearboxes, but does a remap retain the 'softer' gearshifts - yours may be a good example as reference Wammers? My 1st-2nd on a gentle throttle (with the PSI box) is noticeably more harsh than with it disconnected (it's a recently fitted Ashcroft ZF -22 box). On full throttle, the changes are better! I've sent an email to Jeremy Fearn to discuss the remap topic and will see what his comments may be. Another chap I've dealt with (BeCM issues!) was Eric Turner of Turner Diganostics - they are offering a remap too with final tuning on a rolling road dynamometer... Whoever can improve the lowdown grunt is likely to get the dosh as I think everybody promises +/-30% midrange improvements.

Think you had better do a bit of digging about Turners before you even let them blow the tyres up. I am saying no more. Try wearing some heavier shoes. Give them throttle and they will go. I have no problem at all pulling out into traffic if that is what is bothering you. If you want acceleration by a Porsche.
 
Think you had better do a bit of digging about Turners before you even let them blow the tyres up. I am saying no more. Try wearing some heavier shoes. Give them throttle and they will go. I have no problem at all pulling out into traffic if that is what is bothering you. If you want acceleration by a Porsche.
I'll dust off the old steel toe-cap Doc's in the back of my cupboard! Cheaper than a Porsche...
 
I'll dust off the old steel toe-cap Doc's in the back of my cupboard! Cheaper than a Porsche...

Before you deal with Turners do a search on here, some very harrowing tales from those who have entrusted work to them. Better person to talk to about things is Rick-the- Pick a member on here, PM him.
 
I looked at powerboxes and came to the conclusion that the only real way forward was a remap. However, the mapping of the Range Rover, Vauxhall Omega and BMW are different and presumably for good reason. The driving characteristics and weights are totally different. It seems to make sense to take the Rangie mapping and compare to the BMW and tweak up the Rangie one where it is a bit low. However, where I found lots of people who had chipped beamers, none had played with a Rangie. So in the end I left it. That M51 head is already working hard. Get it wrong and that's the head gone. I'd rather have longer life with some room for error! As Wammers says, stick your foot down and it responds pretty well anyway.

This link is to the Omega Owners forum where he takes you through the basics: http://www.omegaowners.com/forum/index.php?topic=100119.0

If you have a hot-start problem you can adjust the map to get rid of that. You'll see they had some very optimistic maps for an old car, one of the reasons a good battery is so important on these cars.
 
I had a hot start problem and took my pump off and sent it for testing and repair to AP Diesels and got very prompt service from them and when it was fitted noticed that the low down response was much better and it also cured my hot starting problem.
 
Power boxes are built from resistors to fool ECU to make it think that it needs more fuel. It simply lifts real fuel quantinity in all circumstances, that's why gear changes are so harsh.
I have 3 rangies with 2.5 diesels, first one is chipped, second has switchable(with button on dash) power box and third is stock(newer version with MAF). Only the one with power box switched ON has harsh shifting problem, turn it off and it's smooth as silk. Chipped one also shifts smooth, and it revs to the redline much faster and smoother with no torque jumps. Only cruise control sometimes behaves weird with lots of thinking when you click "restore speed". But it's probably related to dead in tank pump and lack of low down torque.
 
Power boxes are built from resistors to fool ECU to make it think that it needs more fuel. It simply lifts real fuel quantinity in all circumstances, that's why gear changes are so harsh.
I have 3 rangies with 2.5 diesels, first one is chipped, second has switchable(with button on dash) power box and third is stock(newer version with MAF). Only the one with power box switched ON has harsh shifting problem, turn it off and it's smooth as silk. Chipped one also shifts smooth, and it revs to the redline much faster and smoother with no torque jumps. Only cruise control sometimes behaves weird with lots of thinking when you click "restore speed". But it's probably related to dead in tank pump and lack of low down torque.

That is because the Power box seems to override the torque reduction signal from the gearbox ECU to the ECM on changes. This has been mentioned before by a few people. And is possibly why Powerbox equipped units tend to turn sprag clutches inside out in the gear box from time to time.
 
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