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LDV Pilot 1.9d DW8 2005 - Misfiring and smoking but OK with MAF sensor off - Fixed #

Posted by George Ambelas on October 1, 2013, 7:07 pm

Year of Manufacture *: 2005
Engine Size and Code *: 1.9d dw8
( Optional ) ECU Type: lucas dcn2
( Optional ) Scanner Used: superscan 2
( Optional) Fault Codes: none

hi everyone I am struggling a bit with this one
it starts ok but starts to misfire at 1600rpm
and also starts to blue smoke this it does while driving or in the workshop if I hold the revs at 1600rpm. I have checked for air bubbles and replaced the fuel filter checked the egr and a lot of other things and just by chance I found out the it runs well with the air mas meter disconnected no misfiring and no smoking. so out comes the scope. the idle signal was 2.36v and max. 3.84v 2 years ago I had taken a sample of this ams and it was idle 1.96v and max. 3.84 could this difference cause it to overfuel does anybody have any data for this ams? it's a siemens and the ecu is lucas dcn2 also used in the old Peugeot expert

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by Chris Angus <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT5111' width='330' height='300' border=0 style='border:none;'> on October 2, 2013, 11:49 am, in reply to "ldv pilot missfiring and smoking but ok with ams off"

Is it a turbo model, check for boost leaks. sometimes the turbo will be over speeding so you will get a higher maf output so will give more fuel and smoke.

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by george ambelas <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3245' width='330' height='300' border=0 style='border:none;'> on October 2, 2013, 8:39 pm, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"
George Ambelas

no chris it does't have a turbo. the engine starts well and idles fine but it overfuels at mid range. above that it clears. if I disconnect the ams it's perfect. I will have to do more tests
to what affects the ams output the egr

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by aidan birley <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT2879' width='330' height='300' border=0 style='border:none;'> on October 2, 2013, 9:06 pm, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"
Aidan Birley

George

Have you checked low pressure fuel supply ? restrictions, flow etc.

Contaminated fuel ?

Can a diesel ' Over fuel ' at mid range ?? any extra fuel on a diesel will just increase engine speed, that's how they work !

It could of course be short of air !

Am I correct in thinking this is a rotary pump ? if so timing solenoid fault ?

EGR OK ?

Cheers Aidan

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by george ambelas <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3245' width='330' height='300' border=0 style='border:none;'> on October 3, 2013, 9:14 pm, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"

hi aidan the misfiring and blue smoking disappears when I disconnect the ams so this rules out fuel contamination or timing. this is the old system with the rotary pump. please take a look at the live data with ams connected at 2560rpm requesting 7.3mm of fuel and again with ams disconnected requesting 5.6mm I think the ams is overestimating the amount of air passing through it.

how else can you explain that the fault is corrected after disconnection?

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by aidan birley <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT2879' width='330' height='300' border=0 style='border:none;'> on October 3, 2013, 10:39 pm, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"
Aidan Birley

George

Don't forget that disconnecting MAF will log fault codes and put the ECU into a default strategy, e.g Possibly disabling the EGR etc.

So what is the EGR doing at the same speed with MAF connected / disconnected

what is the actual flows rather than requested?

You could be correct but I'm not convinced that The MAF has that much influence on fueling on this system, possibly EGR monitoring and (black) smoke limiting at high load / speeds only.

A diesel engine at low load should be running with a surplus of air so what effect would adding extra diesel have ? ?

Cheers Aidan

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by Mark Carter <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on October 3, 2013, 11:53 pm, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"
Mark Carter

Disconnecting the AMM will affect the ECU's control strategy.

I think you need to think of Cause and effect.

Mark

Modern cars, Its all wizardry and witchcraft

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by george ambelas <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3245' width='330' height='300' border=0 style='border:none;'> on October 4, 2013, 11:42 am, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"
George Ambelas

hi everyone and thanks for your comments. live data is limited on this system and it does't show actual fuel flow or egr the live data I have posted now is with my superscan 2 and it's all the data there is. I will do more test with the egr when I will get the van back in

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by Mark Carter <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on October 4, 2013, 4:48 pm, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"
Mark Carter

I'm assuming that was with the AMM disconnected ?

Mark

Modern cars, Its all wizardry and witchcraft

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by george ambelas <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3245' width='330' height='300' border=0 style='border:none;'> on October 4, 2013, 10:49 pm, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"
George Ambelas

no it was with ams connected

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by Mark Carter <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on October 5, 2013, 12:21 pm, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"
Mark Carter

That's very intresting.

Either I'm going mad ( which is always possible) or something does not make sense. Look at your data and see what jumps out at you.

Mark

Modern cars, Its all wizardry and witchcraft

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by Kevin Apps <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT2589' width='330' height='300' border=0 style='border:none;'> on October 5, 2013, 1:39 pm, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"
Kevin Apps

Hi Mark.
"Either I'm going mad ( which is always possible"

What do you mean GOING

Yes i can see it as well.

George.
Do the live data again with the AMM dis-connected and compare.

Kev.

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by george ambelas <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3245' width='330' height='300' border=0 style='border:none;'> on October 5, 2013, 1:58 pm, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"
George Ambelas

this is with ams off

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by Mark Carter <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on October 6, 2013, 11:33 pm, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"
Mark Carter

Carry out the same test as before (at the three Rpms) and compare the results, then think about why the AMM is there (on a diesel)

The engine runs with excess air, which means the engine will draw in an amount of air that is equal to the displacement of the cylinder on the induction stroke.

The volume of fuel injected is dependent on the torque requirement of the engine and will therefore alter with load but the volume of air will not, it will only change due to boost pressure (forced induction)

So why bother to fit a AMM if the air flow could be worked out via the cc of the engine and the current boost pressure?

Modern cars, Its all wizardry and witchcraft

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by george ambelas <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3245' width='330' height='300' border=0 style='border:none;'> on October 7, 2013, 10:13 am, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"
George Ambelas

I understand your logic. and in that case if the ams does not have a say in the fuelling why does the fault get corrected once it's disconnected? could it be this forces the ecu to default state and thus changes the injection pump's timing?

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by Kevin Francks <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT5232' width='330' height='300' border=0 style='border:none;'> on October 7, 2013, 8:30 pm, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"
Kevin Francks

This might help George

http://www.vdo.com/generator/www/com/en/vdo/main/products_solutions/special_oem_solutions/platform_products/sensors/engine_chassis_sensors/mass_airflow_sensor/mass_airflow_sensor_en.html

Kevin.

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by Mark Carter <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on October 7, 2013, 11:00 pm, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"
Mark Carter

>>> if the ams does not have a say in the fuelling <<<

Oh but it does, Franks post will help but that's only half the story.

Mark

Modern cars, Its all wizardry and witchcraft

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by george ambelas <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3245' width='330' height='300' border=0 style='border:none;'> on October 8, 2013, 2:05 pm, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"

I have found the fault it was the egr valve not opening. I have managed to temporarily jam it open and run it with everything connected and it's perfect no misfiring and no smoke. it seems that it was affecting the ams as more air was passing through it giving the wrong signal to the ecu and off course to the inj. pump to release more fuel at the wrong time. at least this is how I understand it. anybody cares to add any thing to it.?
ps any body knows where I can find a good used throttle body or maybe have it repaired?

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by Mark Carter <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on October 8, 2013, 10:24 pm, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"
Mark Carter

Does it still accelerate correctly with the EGR valve jammed open?

Mark

Modern cars, Its all wizardry and witchcraft

Re: ldv pilot missfiring and smoking but ok with ams off

Posted by george ambelas <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3245' width='330' height='300' border=0 style='border:none;'> on October 9, 2013, 5:50 pm, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"

View My Video
yes no more of this. of course the egr jamming was for testing purpose only now I know this was the reason for the misfiring and the smoking and I have to change the throttle body if I can find one

Fixed #

Posted by George Ambelas on November 30, 2013, 9:15 pm, in reply to "Re: ldv pilot missfiring and smoking but ok with ams off"
Edited by board administrator December 2, 2013, 6:37 pm

this one is fixed now after a long time searching for a throttle body I have finally found one fitted it and it's now back to normal. out of curiosity I removed the egr diaphragm and it was split

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