Weak Td5

So, I finally got the new temp sensor. Temp readings are now accurate, approx 10 degrees below coolant temp and the engine runs better, but still - best result with the fuel temp sensor disconnected! Don't know how to interpret these results. Is it a fault in the ECU? For now I prefer driving with disconnected sensor, but it bugs me. I would really like to get this working with the sensor connected, but there is a significant loss in power, although better than with the old sensor. What do you guys think?

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Originally Posted by persod

So, I finally got the new temp sensor. Temp readings are now accurate, approx 10 degrees below coolant temp and the engine runs better, but still - best result with the fuel temp sensor disconnected! Don't know how to interpret these results. Is it a fault in the ECU? For now I prefer driving with disconnected sensor, but it bugs me. I would really like to get this working with the sensor connected, but there is a significant loss in power, although better than with the old sensor. What do you guys think?

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Hmmm... just putting it out there.....could the fuel temperature sensor be faulty.....

You should record two data logs, one with the sensor connected and one with it unplugged and post them here

Fuel temp sensor will reduce fuelling when cold to compensate for the higher density of the diesel.
If the sensor is working properly you will need to get the engine up to normal operating temps and then compare connected with disconnected sensor.
Default in the Ecu for the fuel temp is around 70c iirc.

edit; just checked and the default is 60c.

Paul.

Might be a glitch in the fuel map if the sensor reading is OK but the engine behaviour is not, the FT sensor's input has a very complex effect, here's the info: Fuel Density Compensation maps | DiscoTD5.com

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Originally Posted by sierrafery

You should record two data logs, one with the sensor connected and one with it unplugged and post them here

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Took her for testdrives today, and logged the data. Drove the same short strip twice, trying to stay at 90 km/h. The drive ends with a climb, not to steep. Without sensor it stays in lockup the whole way to the top, preserving speed (almost), but with the sensor connected it leaves lockup early and then gears down to third. Don't know if the data gives any useful information but here are the files:Attachment 141372Attachment 141373

I'd put a new coolant temp senor too if i was you cos it seems it reads low as well, or at least swap the ECT with FT sensors for test... is the new FT sensor a good brand?