Nanocom analysis - EDC fuelling

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
Grrrrrr

Grrrrrr

Technician, Bodgit & Scarper Ltd
Full Member
Posts
19,297
Location
Buckinghamshire, UK. ('95 DT)
Well, I've been continuing my play with the Nanocom while on holiday and taken some traces of the EDC fuelling. The question is: what the chuff is it telling me and is my car running as it should?! Again, I'd be interested in other people's data to compare. By the way, this is off a 2.5DT (manual) from 1995. 120 odd thousand on the clock.

Wammers has already provided some vital information (missing from the Nanocom manual) that the SWG setpoint should be below 1500 mV at idle (750rpm), the idle part missing from the manual!

Should all measurements be performed at idle? Is that why the rpm isn't included in the trace? Seems a bit odd because depending what the throttle and load is doing I'd imagine you'd want different fuelling?

Anyway, below are links to 3 days testing. Some files have a break where the car was stopped and restarted.

SWG setpoint. Going to have to revisit this as I didn't realise it had to be idling.

Fuel difference: seems pretty consistent. The odd spike where current amount is greater than compared, presumably when I've backed off the throttle or something, but other than that OK?

Injector: should be within 0.5 of setpoint. Well, most of the time it is! Is this supposed to be just at idle too? It does spike outside it but is that allowed if I stamp my foot down or back off the throttle?

Timing modulation: should be between 45 and 55 when warm. Please, please let this be at idle ... and even then I'm going to have to recheck. Mine's almost never between 45 and 55. Is that a sign that something is way off? Or just not idling?

Fuel temperature: who'd have thought it would get up to 75C? Is that real? Is that sensible? I guess it has a fuel heater and hot diesel is easier to burn that cold diesel. Sound about right?

Links here as files too large to upload:

https://drive.google.com/file/d/0By7n3F7TXDU8TERnWkkya3ZvcE0/edit?usp=sharing

https://drive.google.com/file/d/0By7n3F7TXDU8b3FDd29wWS1pYjQ/edit?usp=sharing

https://drive.google.com/file/d/0By7n3F7TXDU8VGFWSXI5T1V4VVU/edit?usp=sharing

Thought and comments or data welcome!

Cheers,

J
 
Just been out and rerun at idle. Still doesn't make sense. My SWG setpoint NEVER gets below 1500 mV, even at idle. Only just noticed there are 250 rpm markers between each 1000 apart from 0 - 1000 rpm where there are only 2 markers, presumably 333 and 666 rpm?! I digress ... results attached. Last minutes the engine was in the white markers on the temperature gauge so clearly warmed up. Timing modulation NEVER between 45 and 55. Is this all pointing at stretched chains? Link to latest here:

https://drive.google.com/file/d/0By7n3F7TXDU8MklyaEU2YWFjTVk/edit?usp=sharing

I need a beer!
 
And then tackle the Nanocom forum. Avoided that so far. 1 forum is enough ... maybe difference in SWG setpoint and actual shouldn't be more than 1500mV. Still doesn't explain timing difference. Grrrrrr.
 
Grrrrrr said:
Just been out and rerun at idle. Still doesn't make sense. My SWG setpoint NEVER gets below 1500 mV, even at idle. Only just noticed there are 250 rpm markers between each 1000 apart from 0 - 1000 rpm where there are only 2 markers, presumably 333 and 666 rpm?! I digress ... results attached. Last minutes the engine was in the white markers on the temperature gauge so clearly warmed up. Timing modulation NEVER between 45 and 55. Is this all pointing at stretched chains? Link to latest here:

https://drive.google.com/file/d/0By7n3F7TXDU8MklyaEU2YWFjTVk/edit?usp=sharing

I need a beer!
Click to expand...

If the timing modulation is not between 45% and 55% the static timing is incorrect. Below 45% advanced, above 55% retarded. Retarded would indicate stretched chain. A lot above 55% would indicate worn chains. With new chains static is set to 0.95 mm lift on cam, that is setting delivery port in piston slightly open at TDC. When the chains stretch that drops back to 0.90 mm the standard setting. There is a very clear 750 RPM mark on the rev counter the one before 1000 RPM is 750 RPM. Pump setting should be 128 for 750 RPM. Get the static set correctly before you start going off on tangents about the rest of the readings. All readings are taken at idle 750 RPM warm engine. These are the baselines. What is your timing modulation at 750 RPM warm engine?
 
Last edited:
wammers said:
If the timing modulation is not between 45% and 55% the static timing is incorrect. Below 45% advanced, above 55% retarded. Retarded would indicate stretched chain. A lot above 55% would indicate worn chains. With new chains static is set to 0.95 mm lift on cam, that is setting delivery port in piston slightly open at TDC. When the chains stretch that drops back to 0.90 mm the standard setting. There is a very clear 750 RPM mark on the rev counter the one before 1000 RPM is 750 RPM. Pump setting should be 128 for 750 RPM. Get the static set correctly before you start going off on tangents about the rest of the readings. All readings are taken at idle 750 RPM warm engine. These are the baselines. What is your timing modulation at 750 RPM warm engine?
Click to expand...

Timing modulation averaging 82% on warm idle. It sits bang on the second 750 rpm mark except when the air-con clutch cuts in.

When you say pump setting, which setting is that? Fuel start quantity? My fuel start quantity is 32 mg/str, presumably milligrams per stroke?
 
Just re-reading this I reckon I'd better get the static checked first which means someone with tools and experience.

Strangely enough an opportunity might just be on the horizon. Hope it doesn't break first!
 
Grrrrrr said:
Just re-reading this I reckon I'd better get the static checked first which means someone with tools and experience.

Strangely enough an opportunity might just be on the horizon. Hope it doesn't break first!
Click to expand...

was in the same boat as you

FIP was fecked! sorry to break the bad news
 
Grrrrrr said:
Timing modulation averaging 82% on warm idle. It sits bang on the second 750 rpm mark except when the air-con clutch cuts in.

When you say pump setting, which setting is that? Fuel start quantity? My fuel start quantity is 32 mg/str, presumably milligrams per stroke?
Click to expand...

Go into settings you will see a lot of boxes with numbers in them. DO NOT change any other value other than the idle speed setting if it is needed. That should be 128. Change only by one or two points. Lower number lowers idle speed, higher number raises idle speed. Think you had better read the instructions again it is all explained in there. Personally at 82% i would be checking chains for wear if one snaps you are up ****s creek without a paddle. If pump modulation is up at 82% cam timing will also be out. If bottom chain is worn enough to give 82% on modulation top chain that drives cam will also likely be on its way home.
 
wammers said:
Go into settings you will see a lot of boxes with numbers in them. DO NOT change any other value other than the idle speed setting if it is needed. That should be 128. Change only by one or two points. Lower number lowers idle speed, higher number raises idle speed. Think you had better read the instructions again it is all explained in there. Personally at 82% i would be checking chains for wear if one snaps you are up ****s creek without a paddle. If pump modulation is up at 82% cam timing will also be out. If bottom chain is worn enough to give 82% on modulation top chain that drives cam will also likely be on its way home.
Click to expand...

Thanks Wammers. Really useful to me, even if it was flogging a dead horse. :)

I won't change that until the static is checked, after all it is idling bang on 750rpm so that's OK, isn't it? I will of course go out and have a look at boxes though! Got a nagging suspicion in the back of my mind that it is already at 128.

Oddly enough my next questions were going to be: how far can you adjust the static timing and how far can you push it before a chain is likely to snap. That explains that!

I had a look at Johnny's threads. To be fair the timing doesn't look that difficult with the dial, dial attachment and the locking thingy. However, replacing the chains? That sounds like a real opportunity for Captain Cock-up to visit a rookie. I'll have a read through RAVE and have a think. Like the idea of doing it but ... :eek::eek::eek:

Maybe if I just wait for the missus to visit her mother's and then I'll quickly take it apart and if it all goes wrong blame burglars or somesuch!
 
Grrrrrr said:
Thanks Wammers. Really useful to me, even if it was flogging a dead horse. :)

I won't change that until the static is checked, after all it is idling bang on 750rpm so that's OK, isn't it? I will of course go out and have a look at boxes though! Got a nagging suspicion in the back of my mind that it is already at 128.

Oddly enough my next questions were going to be: how far can you adjust the static timing and how far can you push it before a chain is likely to snap. That explains that!

I had a look at Johnny's threads. To be fair the timing doesn't look that difficult with the dial, dial attachment and the locking thingy. However, replacing the chains? That sounds like a real opportunity for Captain Cock-up to visit a rookie. I'll have a read through RAVE and have a think. Like the idea of doing it but ... :eek::eek::eek:

Maybe if I just wait for the missus to visit her mother's and then I'll quickly take it apart and if it all goes wrong blame burglars or somesuch!
Click to expand...

Dodgy ground there, i have yet to hear of a burglar having any number of counts of changing P38 timing chains taken into consideration in court. :D:D:D
 
Hmmm. Probably worth doing cam chains at the same time while it is all apart?

Had a look at Island and can get upper and lower chains, sprockets, tensioners and guides all for under £350. Would you replace the lot or just the sprockets and chains?
 
Grrrrrr said:
Hmmm. Probably worth doing cam chains at the same time while it is all apart?

Had a look at Island and can get upper and lower chains, sprockets, tensioners and guides all for under £350. Would you replace the lot or just the sprockets and chains?
Click to expand...

what's the use putting new chains and sprockets and leaving the old guides and tensioners?:rolleyes::D
 
That was my feeling but I've no idea what the relative materials are made of so no idea of relative wear rates. Considering the expense it is probably worth it anyway. Glowplugs too for that matter.

Had a read last night. There seem to be a number of special tools required to lock things and release tensioners. Could cost a fair bit in tools if I do it by the book. My shed isn't exactly a workshop! Heaven knows what it would cost to get someone else to do it.
 
Grrrrrr said:
That was my feeling but I've no idea what the relative materials are made of so no idea of relative wear rates. Considering the expense it is probably worth it anyway. Glowplugs too for that matter.

Had a read last night. There seem to be a number of special tools required to lock things and release tensioners. Could cost a fair bit in tools if I do it by the book. My shed isn't exactly a workshop! Heaven knows what it would cost to get someone else to do it.
Click to expand...

You will need this. BMW & LANDROVER 1.8 2.5 TD TDS TD5 P38 CHAIN DRIVEN ENGINE TIMING TOOL SET | eBay This US PRO VW 3-IN-1 BOSCH VE INJECTION PUMP TIMING TOOL US3178 | eBay This Dial Test Indicator / DTI Guage / Clock Gauge TDC TE107 | eBay And the chains tensioner rails and sprockets plus gaskets. Plus a good set of tools a torque wrench and an angle tightening gauge. Although that can be done without if you realise each flat point to point is 60 degrees.
 
You must log in or register to reply here.

Similar threads

tweedandbriar
Need a bit of guidance....
Replies
1
Views
339
tweedandbriar
tweedandbriar
W
Series 3 diesel knock
Replies
9
Views
997
Bobsticle
Bobsticle
F
P38 DSE loss of power when driving
2
Replies
33
Views
1K
Mark Piercy
Mark Piercy
pwood999
P38A RAVE All Models - Individual PDF files.
Replies
4
Views
1K
Allrounder
A
jimmacD
P38 Nanocom neebie!
2
Replies
24
Views
2K
Datatek
Datatek
Back
Top