TD5 - and my massive headache.

Hi Tazz ... I don't feel the stutter when in Neutral. Good questions - thx!

Lars

The flywheel has been replaced two years ago (max 20k miles) and was replaced due to this problem ) ...

But ... flywheel sensor? IO have never heard of such sensor .

Lars

Hi SierraFery ..

Good idea to check the actual values. I will do so when I have fitted the new harness. I also want to look at the sensor values with an oscilloscope - it should show any misfire as a uneven (cut) sinus wave..

Lars

But ... flywheel sensor? IO have never heard of such sensor .

Lars

Sensor is on the right hand side of bell housing about half way down I do believe.

Gooders70 said:

Has it had a new flywheel lately? How many miles has your flywheel done? Seen it before on tdi VW, when flywheel gets worn it moves about a lot more and gives an uneven signal to the flywheel sensor! Just a thought!

Click to expand...

the crank sensor reads of fixed part of flywheel not damped so cant move unless rear main bearing is gone in which case sensor would be pointless

Sensor is on the right hand side of bell housing about half way down I do believe.[/quote]

... ah .. the crank position sensor ..

Update!

Engine harness (not injector harness) has been replaced. No changes. While replacing the harness i spliced a few wires and fitted a swith so that I am able to control the hi/low gearbox input to the ECU. Hereby I have the option to use the throtthle sensitivity of the low range mode - while actually driving i high range. This does not eliminate the problem – but the ride is somewhat smoother.

Next steps:

1) Validate the CKP sensor output via voltmeter and a oscilloscope. The sinus curve may show signs of misfire – if any?
2) Borrow a Nanocom from somebody and record live data while driving.
3) Validate fuel pressue (min. 4 bar).
4) Sell the car if 1, 2 and 3 does not solve the problem.

Lars

Did you have this stutter before the remap ?


Have you also checked the throttle potentiometer values ? Dont know where you would get the values, but the ecu relies on the voltage inputs from this to provide the fuelling as per the map you have running.

See if you can swap/borrow an identical one from another td5.

On software I use for a DTA ecu - you have to calibrate the values from the throttle pot to allow the ecu to understand when the throttle is completely shut, and completely open.

Am I correct your happy with the re-map integrity ?

Thank you for your input T66!

Yes the stutter was also present prior to the remap.

The throttle has been replaced .. which changed nothing. I'm not sure about the calibration part ... are you sure this is needed on the Td5? .. and ifso, maybe this was already done when the new ECU was fitted ... no clue.

The remap itself is ok. I'm pretty happy with it. AliveTuning did a good job. Only 'concern' for me is that the remap was done by 'long distance' so there has been no performance validation as I would expect of you visit Alive Tuning at their own workshop.


Lars

Lars,

Have you checked fuel pressure? The Td5 fuel sender pumps volume, the fuel pressure regulator at the back of the engine creates a restriction so that fuel rail pressure stays above 4 bar. Either a dodgy fuel pump or FPR can cause fuel starvation, which can reveal itself in the form of poor engine performance, miss-firing, stuttering, etc.

...bummer! see this is on your things to check list...

Suggest you also try a good working ECU.

Td5 TPS does not need calibration.

Would gladly look at Nanocom fueling data if it helps.

Rgds
Matt

have you tried to get it plugged in and look for ECU fault codes ???

Thanks Matt! ;o)

I do suspect that fuel pressure could be an issue. But it will take me a couple of weeks until I see my friends workshop where I can validate the fuel pressure. I will keep you all posted.

However, latest by Tuesday I should receive a Nanocom which I just bought second hand. Thank you - I will definitely need some support in evaluating data!

... and the ECU is new too ) ... just as the fuel pressure regulator ... )

Thx for great support!!!

Lars

Hi Jay! when tested earlier - there were no faults..

However, by next week I will dig into the ECU with a 'new' Nanocom ... let's see what it will tell me ...

Lars

Update!

Nanocom arrived and I have the first data available.
Injectors does have some peaks that looks a little disturbing but in general all most values are within +/- 10.

However please have a look at the following two pictures. This visualize the feeling I have had that the rev keeps going up even though the throttle is steady....

Lars

Lars,

What year model is it and how much road has it seen (kms)?

Rgds
Matt

Defender 90, TD5, year 2000, 185.000 km (110k miles)...

I believe that I have found the problem! The clutch switch sends out a reversed signal. I have earlier registered that there is a clear signal (closed and non-closed circuit) as there should be. However today I realize that the signal is reverse. I have been testing the signal directly on the switch - and not just through the Nanocom.

So, when the clutch is released (rest position) - there is no signal. When I press down the clutch pedal I get a closed circuit signal. This is wrong. The signal should be closed while the pedal is in rest.

-------------------
From the workshop manual:

SWITCH - CLUTCH PEDAL
The clutch pedal switch is located on the clutch master cylinder and is activated when the clutch pedal is operated.
The ECM uses the signal from the clutch pedal switch to provide surge damping during gear change.

Surge damping stops engine speed rising dramatically (engine flaring) during gear change.

Surge damping assists driveability as follows:

• Smoother gear change.
• Greater exhaust gas emission control.
• Improved fuel consumption.

Input / Output When the clutch pedal is in the rest position, the clutch switch is closed. This allows a feed to flow from the switch (C0667-1) to the ECM (C0658-35) on a black/white wire. When the clutch pedal is pressed the switch contacts open, cutting the feed to the ECM.


The clutch pedal switch can fail in any one of the following ways:

• Switch open circuit.
• Short circuit to vehicle supply.
• Short circuit to vehicle earth.

In the event of a clutch pedal switch failure surge damping will be inactive.
-------------------------

... but the switch is not inactive ... it's reverse!

This makes perfectly sense! This is why the throttle feels very sensitive. There is no surge damping when there should be – and plenty when not needed!!!

But HOW on earth is this possible?? Is it the wrong switch or does the clutch master cylinder have a problem??

Lars

I dunno if what u say it's possible

1. how did u verify the signal on that switch? ..did u unplug it and put ohmeter on its contact?

2. If u have cruise controll and that is working normally the switch and it's signal are fine

anyway the surge damping occures only during gear changes and for short while like when u push hardly the throttle in neutral and wait few seconds untill it gets back to idle.

Go for a ride with it unplugged and see what happens

Hi Sierrafery!

Thank you for your input!

1.) Yes - I have tested the switch directly with a ohmeter...
2.) I have no cruise control..

I did test this with the switch unplugged. I even looped the wire to the ECU and this is where my concern started. When looped, the revs kept staying high even when depressing the clutch pedal – just for a few seconds. If the switch would have been connected (and working as it should) then the revs would be cut of when I depress the clutch….

I also verified the signal on a different Defender .. mine is reverse.

I have a feeling that there is something wrong with the switch – all though it is brand new. I have a spare (old one from previous replacement). I will test this unit today to see if the signal pattern is identical.

Maybe I have TD4ci sensor. I believe they have a reverse signal?

Lars

Buckhandle said:

Hi Sierrafery!

I did test this with the switch unplugged. I even looped the wire to the ECU and this is where my concern started. When looped, the revs kept staying high even when depressing the clutch pedal – just for a few seconds. If the switch would have been connected (and working as it should) then the revs would be cut of when I depress the clutch….


Lars

Click to expand...

Exactly, then a good closed contact switch must solve the problem.... though i dont see the connection with the too sensitive throttle...good luck