[tishobg]

It's a 147 diesel 16V - 140HP variant with a remap to about 175HP. I've got MES and I suspect something is wrong due to my poor fuel consumption.

Which values should I check on diagnosis to see if there is indeed something wrong, perhaps a drop in pressure, vacuum leak, airflow? It's the free version of MES. MPG I'd say is about 31-32MPG on short journeys around town while I think around 38MPG should be expected in my scenario.

 

[halftone]

I think that's normal. I live in London, and wouldn't expect any different from short journeys in cold weather - it guzzles DERV until warmed up.

I keep a lifetime log of fuel use. My all time worst was 29mpg, when I was doing a lot of back and forth short trips carrying boxes of books, each from a cold start, in cold weather. Average is 37mpg over 4 years, but I get 49mpg on a sensible run. It would be higher if I didn't have London congestion and speed humps to cope with before I can get to any sensible road.

A good re-map won't make any difference, if you drive the car the same - although the computer will claim spectacular MPG it's lying. Mine has deleted EGR and swirl flaps. I can't say whether they make any difference as the car had swirl flap damage when I bought it.

Unless you have other issues, the only thing you might want to check is that it's not taking an unusually long time to get to 90C. That would point to the thermostat sticking part open. In hot weather mine gets to 90C in a little over 2 miles, at 0C it's about 4mls.

 

[tishobg]

I think that's normal. I live in London, and wouldn't expect any different from short journeys in cold weather - it guzzles DERV until warmed up.

I keep a lifetime log of fuel use. My all time worst was 29mpg, when I was doing a lot of back and forth short trips carrying boxes of books, each from a cold start, in cold weather. Average is 37mpg over 4 years, but I get 49mpg on a sensible run. It would be higher if I didn't have London congestion and speed humps to cope with before I can get to any sensible road.

A good re-map won't make any difference, if you drive the car the same - although the computer will claim spectacular MPG it's lying. Mine has deleted EGR and swirl flaps. I can't say whether they make any difference as the car had swirl flap damage when I bought it.

Unless you have other issues, the only thing you might want to check is that it's not taking an unusually long time to get to 90C. That would point to the thermostat sticking part open. In hot weather mine gets to 90C in a little over 2 miles, at 0C it's about 4mls.

While I do drive the car the same pre- and post-remap, I enjoy moving off stop lights swiftly, which makes use of the added torque. Mine has the EGR delete as well and being CF3, hasn't got swirl flaps from the factory.

I usually do no more than 2 miles trips, university is 1.5 miles away and it's almost at operating temp when I get there in the summer, much worse in the winter - probably around 60. My longest trips in town are 5 miles before shutting the car off. Speed bumps, traffic lights and congestion is London-like in rush hour.

I don't have any other symptoms, car moves the same and still puts a smile on my face every time I floor it. I try to take it once every month or two on the private motorway for a trash to clear out it's throat as to prevent any clogging up.

Just talking with mates and other Alfa owners, some of them report high 30s with the same usage as mine, makes me wonder if something is wrong with mine.

 

[Bsrgt]

That's normal given the colder weather and short trips conditions. Buddy with a derv 156 does 8-9L on a cold short trips.

 

[frosty984]

It's a 147 diesel 16V - 140HP variant with a remap to about 175HP. I've got MES and I suspect something is wrong due to my poor fuel consumption.

Which values should I check on diagnosis to see if there is indeed something wrong, perhaps a drop in pressure, vacuum leak, airflow? It's the free version of MES. MPG I'd say is about 31-32MPG on short journeys around town while I think around 38MPG should be expected in my scenario.

That mpg is very good actually for in town driving. My friends 16V has 29 mpg easily of in town driving so I would say that you are spot on. Your biggest variable is the remap. As far as MES you should compare current and target MAF and MAP values. To really test the injector they must be flow tested on a bench, injector correction values are unreliable and do not represent the actual condition of an injector. Sensor-wise, MAF has the biggest impact. Did you do a remap by a reputable dealer?

 

[tishobg]

That mpg is very good actually for in town driving. My friends 16V has 29 mpg easily of in town driving so I would say that you are spot on. Your biggest variable is the remap. As far as MES you should compare current and target MAF and MAP values. To really test the injector they must be flow tested on a bench, injector correction values are unreliable and do not represent the actual condition of an injector. Sensor-wise, MAF has the biggest impact. Did you do a remap by a reputable dealer?

Yes, It's been on the car for ~2 years, Alfa specialist, most of the Alfas in that part of the country are remapped by him. He definitely dialed it in just as I like it - absolutely no smoke no matter how I try - not a fan of smoking diesels. Turbo is at 1.4 bar with 1.6 peaks, but am unaware of the fuel ratios.

Once I get free time on the weekend, I'll hop on MES and test it out. I use a maintenance additive to my fuel (Bardahl BDC) which supposedly keeps the injectors healthy, but I might consider a more powerful cleaner if need be.

 

[frosty984]

Yes, It's been on the car for ~2 years, Alfa specialist, most of the Alfas in that part of the country are remapped by him. He definitely dialed it in just as I like it - absolutely no smoke no matter how I try - not a fan of smoking diesels. Turbo is at 1.4 bar with 1.6 peaks, but am unaware of the fuel ratios.

Once I get free time on the weekend, I'll hop on MES and test it out. I use a maintenance additive to my fuel (Bardahl BDC) which supposedly keeps the injectors healthy, but I might consider a more powerful cleaner if need be.

1600 mbar is the max safe pressure stock turbos run. Injector cleaners in my opinion are a waste of money but they cant hurt anything so...

Plug in MES and do a log in 3rd of 4th gear and see what is the diesel injection quantity in mg on full throttle but since it is not smoking then it probably is not excessive.

 

[pastie]

Do you get a trail of black smoke at high rpm? mine was terrible on fuel til i fixed the MAF and boost leak,now its roughly the same mpg as yours