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Discussion Starter #1
So I checked the oil and the coolant levels - all fine. I checked the ECU, no fault codes. So the car feels sluggish compared to a CF2 2.0TS, it never gets that kick in the back at 3000 RPM that the 2.0 does. I'm suspecting the fuel might be a bit iffy, as it was purchased pre lockdown, but I guess it could be the throttle actuator stucking or the cam variator solenid. But does anyone know how to clean the throttle body on these fly by wire things? Also, does the ECU register faults in the variator solenoid? so many questions, sorry. It is hot after all.
 

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The ECU only registers a circuit fault in the low current side of the variator relay circuit. In other words, it does not monitor the position of the inlet camshaft. Only the integrity of the low current side of the circuit is monitored.

Have you checked the MAF? Using MultiEcuScan it should return around 15kg/hr at warm idle, 150kg/hr at full throttle by 2000rpm and over 400 kg/hr (really 420) at full throttle at maximum power speed (6300rpm for a 2.0 TS).
 

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Discussion Starter #3
Fruity, you are the bee's knees! I only have AlfaOBD, and the sun has been too bright to properly read the laptop display, I do have a baseline warm-up data capture, so making another should be good for a comparison. When you say low current side, are you saying the ECU checks the relay coil, but doesn't check the actuator coil? That sounds like the mad kind of thing Alfa would do .
 

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Discussion Starter #4
Fruity, I am assuming I will need to do the 90-90 ecu reset if I change the MAF? Its probably the original with 166k on it. The last time I looked at the live ECU data the intake temperature seemed a bit high, is that part of the MAF interface? I ask as the issues are happening with a warm car in hot weather. Finally, should I stick with a new Bosch part ?
 

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Apologies that I took my eye off this one.
Yes, it only checks the relay coil but remember those unprotected terminals under the relay which are open to the elements. Our cars aren't German so these things aren't in a sealed box. They can oxidise and cause issues.

There is no need for a throttle reset when changing the MAF sensor but it may be worthwhile anyway. It would be a good idea to check the throttle body and valve is clean first.

Have a look at actual engine speed and desired engine speed on live data; they should agree. I'd expect around 850rpm for idle speed.
 

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Discussion Starter #6
You must be psychic! I replaced the MAF today, and my partner says the car seems a little less hesitant, but since the weather has gone cold again, we havn'e seen the issue that occured with a wormed up engine stalling. I have a spare, known working solenoid on a 1998 2.0TS, will it fit on a 2001 1.8TS ? I may just swap it over if so, and see if that is any better.
 

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The solenoid valves are all the same *(CF1/2/3, 1.6-2.0 whether TS or JTS).
It only allows oil into the variator or not so I doubt changing it will help. I think if it works, it works.

* Not sure if multi plugs are all the same though.
 

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Discussion Starter #8
The solenoid valves are all the same *(CF1/2/3, 1.6-2.0 whether TS or JTS).
It only allows oil into the variator or not so I doubt changing it will help. I think if it works, it works.

* Not sure if multi plugs are all the same though.
My reasoning was that if the solenoid valve is fired by a relay, and only the low tension side of the relay is checked by the ECU, there could be aproblem in the solenoid valve winding or the connections to it. I guess I could measure the resistance of the solenoid, but I read in a thread here implying that sort of test is not reliable.
 

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Displace the relay and perform diagnostic actuator test for variator. I guess that's the best easiest way to test its function.
 

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Argh! I meant the variator solenoid! I think you possibly knew that as the relay would simply log a fault code.
 

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Discussion Starter #12
A quick update. Replacement of the MAF appears to have cured the intermittend stalling issue. I haven't had time to investigate the variator solenoid or driver relay.
 
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