Smokey 1989 (8 valve) 740 B230

[Laird Scooby]

Originally Posted by Volvoaus

Black smokey exhaust finally resolved (at this stage). Not sure what finally fixed it, but I additionally removed the ECU temperature sensor (19mm deep socket - above the PCV), multimeter tested it in ice cold water - boiling water and found there was more resistance then a bunch of WWII French partisans.
Possibly what may have resolved the issue was a full removal of the throttle (butterfly) body and complete clean. Cleaning insitu means its only getting half cleaned. Now whats next?

Can you outline your exact test method on the CTS? There are two sensors in it, both NTC and both have one leg connected to the body of the sensor. One sensor feeds the fuel ECU and the other the ignition ECU so it's entirely possible you only (at best) half-tested each half.
Also what resistance values were you getting at ambient, freezing and boiling?

[Volvoaus]

Thanks for your assistance everyone. Took it for a shakedown. Running really great and now on the market (in Oz):

https://www.carsales.com.au/cars/det...-6832294/?Cr=2

[Volvoaus]

Originally Posted by Laird Scooby

Can you outline your exact test method on the CTS? There are two sensors in it, both NTC and both have one leg connected to the body of the sensor. One sensor feeds the fuel ECU and the other the ignition ECU so it's entirely possible you only (at best) half-tested each half.
Also what resistance values were you getting at ambient, freezing and boiling?

Not sure the CTS you are referring to, however as per the Haynes Manual ECU temperature sensor; buggered up the photo of my ambient reading (had it on ohms=4.01) ice water 2~20 ohms = 11.39 x10 and boiling water 2~20 ohms = .428 x 10. According to, without doubt, very reliable Youtube tutorial I referenced was per the instruction

Main thing, it is now driving smoke free

[Laird Scooby]

Originally Posted by Volvoaus

Not sure the CTS you are referring to, however as per the Haynes Manual ECU temperature sensor; buggered up the photo of my ambient reading (had it on ohms=4.01) ice water 2~20 ohms = 11.39 x10 and boiling water 2~20 ohms = .428 x 10. According to, without doubt, very reliable Youtube tutorial I referenced was per the instruction

Main thing, it is now driving smoke free

The CTS i'm referring to, is the Haynes Manual ECU temperature sensor. One and the sme animal!

You've only half-tested it as you've measured between the two terminals and come up with :

Ambient - 4.01k Ohms
Ice - 11.39k Ohms
Boiling - 428 Ohms.

The YT "tutorial" is obviously wrong as well. As i pointed out, there are TWO sensors inside it, one end of each sensor goes to the terminals you can see, the other ends are joined together and then to the metal body of the sensor.

Measurements are meant to be taken from each terminal to the body of the sensor and will be ~half what you've listed.
Please reassure me you didn't wrap PTFE tape or any other sealant on the threads of the sensor when you refitted it?

Anyway, there's enough info there to be fairly sure (not 100%) it's working ok so you should just about get away with that one.