Help from Jon V8 needed

[d1scv]

Or anyone that can shed light.

An issue I cannot solve on my Td5. Throttle switch seen to be working correctly with engine not running.
But with engine running track 3 remains almost static.
For the first, say 1 inch of throttle track 1 and 2 alter- but has no effect on engine speed.

This, I think is connected to my problem.

When cold starts fine. But any attempt to increase engine speed results in a misfire and grey smoke.

As it warms the misfire almost dissappears. but performance is flat.
No faults are stored. Injector loom is clean.

Hope you are not offended by asking you directly Jon V8, but you seem to be the man to ask.

[Jon v8]

Bit of an odd problem you have there,but I dont think its caused by the throttle pot.I dont bother using Testbook to diagnose driver demand issues,(Throttle pot) as the voltages are only reliable when the pedal is static.Most problems are caused when the pedal is moving,for this I always scope the outputs from the pedal - its easy to see a scratchy output on the screen,compared to a smooth one.TD5 ecu's are more than happy to log faults,so the fact that yours has none makes me think its more likely an airflow issue.Are all the boost hoses clear and in good shape ? Have you tried disconnecting the airflow meter,often as they fail they give a very low reading so the ecu only allows a small amount of fuel - poor performance.
On cylinder balancing at idle are all 5 cyls fairly even ? A plus or minus reading of more than 10 needs looking at.With the AFM connected you should see 55-60KG of air at idle and about 330KG at 3000rpm running free.
Throttle pot issues normally make the engine shut down to idle and refuse to rev at all.

[d1scv]

Jon V8, thanks a million for replying.
I need to get my head round all the points you have raised!

At idle, cylinder balance is OK, but with a cold engine, slightly lifting the RPM to [say] 1000 rpm the balance is bad. I mean +/- 20.

Idiot question- why does the throttle have no effect in the early stages.
I can see the voltage changing- but zero happens.

I will check the points you have raised, and if I may, get back tomorrow.
Tony

[Jon v8]

Bit wobbly now as supper included a bottle of red.The throttle not having any effect is a worry,as its not logging any faults - but without seeing the rest of the live data it could make sense.This is if the airflow is low,what readings are you getting ?
The other thought is that I have seen a couple of ecu failures recently that have not been common before,they could be suffering from ageing,as some earlier units have.

[d1scv]

Air flow at idle is 60, at 3000 about 220.

The ECU is the later unit [flashable] type.

A pal of mine has a very similar Td5 , a couple of months younger.
Is it possible to fit his ECU- to compare- without over writing my injector codes on his ECU.
Is there any possible danger of infecting his ECU.

Thanks Tony

[Jon v8]

The airflow is well down at 3000rpm - have you tried just disconnecting it so the ecu will run in default ?
Yes you can swap ecu's without rewriting the injector codes,it may not run very smoothly at idle and the top end may not be too good.But it should at least run on 5 without smoking.You will have to do a security relearn to get the car to run the new ecu.

[d1scv]

Sorry- typo- should read 320 @ 3000k

[Jon v8]

OK, that is a good air flow reading - if your friend is happy for you to trial his ecu for a test I think thats the next thing to do.Let us know how it goes.

[d1scv]

Thanks, Jon V8, for your help on this. I agree that my next stop must be to check out ECU.
Couple of last questions.
Can an ECU be repaired. If so by who.

Next I have to get my head round 'security relearn'
I take it that, in principle, I need to record the security settings on the donor vehicle and keep them to restore back again.

'Learn Security' on Nanocom gives little more than the EKA.
I am sure I should be looking for more than this.

[Jon v8]

OK,yes ECU's can be repaired,but I'm not overly impressed with the companies I've tried so far - they arent too expensive to replace,either new or S/H.
The security relearn is done under "Vehicle Maintenance" in the engine ecu menu on Testbook - no idea how to do it with Nanocom - or even if it can do it.Sorry I cant help more with that,maybe someone with Nanocom experience can shed some light on it.

[d1scv]

Thanks Jon V8.