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Discussion Starter #1
I've not driven the alfa much as I've been restoring her. Now noticed that I'm getting under 20mpg (when the fuel dial works - lol). Could this be because I have fitted a CF3 engine - still using the original CF2 ECU and CF2 exhaust? (Fitted all the CF2 bits to it) Could it need tuning? Could it be caused by a blowing exhaust manifold (hairline crack)? Where do I start?
99 156 2.0TS
 

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start with looking at temp gauge, shoud be 90 when its warmed up, if not thats your problem, cannot advise about the engine swap as im not up on that.......could be worth doing ecu reset to learn new parameters of the sensors though
 
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Agree with above. Hi there I did this the other way round CF3-CF2 all I can say at the mo is that most of the bits are the same sensors etc but not sure that the ecu is some of this is down to the emissions regs.
I would have thought that it would be very similar fuel wise if not a little better as you have got slightly less in the way of cats I think .
Will let you know how mine goes but no mot till next week so will have to wait till then.
How are you judging the fuel tank to distance traveled or by the gauge?
Did you change the cambelt or check the timing on the engine you put in?
If the manifold is leaking I think you should notice the noise bit like squeaky fa#t as appossed to the blow you get from an exhaust if you follow me .
Did you change or clean and check the injectors and of course the air pipes and maf?
Have a think and check through some of these see if you find anything. Don't trust the fuel gauge to much as they can be iffy especially if the tank is low on fuel.
 

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Discussion Starter #4
Temp gauge is fine - runs at 90 (occasional brief 100 until fan kicks in). It could be the accuracy of the gauge I'd brimmed the tank though and haven't even done 200 miles before the light's on and the needle is almost on empty.
Everything was renewed on the engine including thermostat and MAF. The manifold is leaking from the underside of one of the pipes - as the engine warms up, the noise improves. I'm going to try the ECU reset - is it same procedure for all 156 and 147's?
 

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The fact you have swapped the CF2 parts over from the CF3 should bear no real relevance. As the ancillaries you have swapped.
I would imagine that its over fueling due to one of the sensors not reading correctly.

A reset may help and making sure you have a computer and fiatmultiscan would be the next point to record the sensors. Even if the engine was cold constantly (Which its not) it wouldn't do mpg that low.

Have you got the old maf leing around you could use. Make sure its fitted the correct way round also.
 
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I s the manifold plate leaking or the pipe weld on the plate?
Have you got 2 manifolds one for each engine or just the one
 

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You don't say how you drive or what journeys you do? Long motorway cruising with smooth acceleration or full revs everywhere tear-arsing around town drag-racing away from the lights, etc? Windows up/down, a/c on/off?

The exhaust blow won't be helping. This will upset the Lambda settings and in turn the fuel mix. Even a dodgy lamdba could be throwing it out ... and you might not get a fault light either. NTK lamdbas are rubbish on a TS ... Bosch only.


I can easily get over 400 from a tank on my 2.0 TS. That's mainly cruising but around 70-75 mph. (I try and hold the revs to 3,250 to 3,500 with an occasional burst to overtake the middle-lane hogs.

I'm really ****ed off if I get less than 300 per tank

(and those figures with no air con) and windows up.
 

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Discussion Starter #8
Well, I've done the ECU reset and it's definitely running sweeter - it doesn't smell so 'rich' either. Fingers crossed that it's sorted. I was doing a mix of driving a couple of miles in traffic then 15 on dual carriageway 60 mph (honest, officer).
 
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