Td5 Misfire

[littlepow]

Started to get an intermitent misfire when I drive my 90. Restarting the engine cures the problem, but as it only seems to occur when it wants to and not every trip. Has anyone got any ideas bar changing the ECU loom under the cam cover?

[Magnum335]

I assume its when you back off the throttle?

[Jimbo]

You mention changing the loom under the cam cover - I guess this is for the injector oil seal problem........have you pulled the two plugs off the ECU (one red, one black) to see if you have the oil problem ?

Jim

[littlepow]

Misfire just occurs while driving, it's not even being consistant on the conditions it has occured in. But once engine is restarted it doesn't happen again for the journey.

[Porny]

Unplug the air flow meter and go for a drive... see if it makes any difference.

And as mentioned, check for oil in red plug on the ECU.



Ian

[Jimbo]

Do you get any warning lights on the dash when it happens ?
Have you got a tuning chip/module fitted ?

Only asking, as I have a Dastek PP and if you don't let it 'boot' for a few seconds straight after starting, the engine coughs and the orange 'engine' light comes on - ignition off/on sorts that out every time.

Jim

[Porny]

Have you got a tuning chip/module fitted ?

Only asking, as I have a Dastek PP and if you don't let it 'boot' for a few seconds straight after starting, the engine coughs and the orange 'engine' light comes on - ignition off/on sorts that out every time.

Jim

You only get that with plug in boxes!!   not a proper replacement chip/remap.  One of the side effects of a plug in box.


Ian

[littlepow]

ECU is in standard form, no chips/plug in boxes.
There are no warning lights on the dash.
Will check red plug after work.

[Porny]

Any joy??

Have you checked the red plug for oil, or disconnected the air flow meter??

Shame your not a bit closer, could have plugged my laptop into your Defender and had a look for any faults.

Ian

[littlepow]

Any joy??

Have you checked the red plug for oil, or disconnected the air flow meter??

Shame your not a bit closer, could have plugged my laptop into your Defender and had a look for any faults.

Ian

All plugs into ECU are clean, with no signs of contamination. Will try airflow meter disconnection  next.
What software / cabling do you use for fault finding?

[Porny]

All plugs into ECU are clean, with no signs of contamination. Will try airflow meter disconnection  next.
What software / cabling do you use for fault finding?

I've got Rovacom Lite... along with the neccessary files/leads.

North Yorkshire isn't that far if you wanted to pay my fuel costs  
(editied for stupidity!!   )


Ian

[Nick666]

North Yorkshire's a bit further :D

[Porny]

North Yorkshire's a bit further :D

I knew what I meant.....    :roll:  :oops:

Is all still 'up north' from me anyway  

[littlepow]

It's about 154 miles. A bit far, but may need your help at a later day.
Thanks.

[suds]

Ian
What difference would you notice on disconnection of Air Flow meter if working and if not working? I have a similar concern on my td5
thanks
Suds

[Porny]

Ian
What difference would you notice on disconnection of Air Flow meter if working and if not working? I have a similar concern on my td5
thanks
Suds

If you disconnect a dodgy/faulty MAF sensor you should notice an improvement in low speed pick up, less hesitation when pulling away, and no low speed misfire.  You may also find that the engine performance is restricted at higher RPM's.

There are other things that can cause misfires on TD5's:

If the Crankshaft Position Sensor is too close to the flywheel (esp. if misfire occurs when the engine is hot) - you could do with reading fault codes off the ECU

Fuel Injector Faults (need diagnostic equipment really)

Fuel Injector Harness Faults (not just oil in the loom) - there was a problem with the harness not being plugged in correctly (faulty plugs)

Loose power feed into the underseat fuse box (though you usually have other electrical problems)



Ian