I get poor mpg from my 2001 abarth 105 jtd.

I've cleaned the egr and reset the ecu.

I get 35mpg (brim to brim method - no trip comp on mine!)

It's all serviced, new filters etc.. and runs well with no smoke and passed MOT today (2 bulbs needed!! phew....

So should I make a plate and blank it at the exhaust manifold?

What should I do with the vacuum pipes so the ecu thinks the egr is still there and working fine??

I've read through quite a bit of this forum and seem to get conflicting ideas!

the egr valve usually increases performance when cleaned but doesnt really alter mpg, its your choice if you want to block or not, you wont fail an mot etc unless your really unlucky to fail an emissions test, i know you have just had one but its for future reference... you could fit a swirl gasket but i dont know where you would get one from, this will keep the egr clean, but it is completely your choice.. i wouldnt block it personally i would either fit a swirl gasket or leave it, if you leave it on and clean or have it cleaned every 50000 then thats fine thats my personal experience from what i have learnt. but again it is up too you. ps if you are in derby and need any mechanical help give me a shout and i will do it for you if you need

forgot to mention have you had fuel filter, replaced and try getting your diesel from somewhere else this may increase your mpg the better the diesel the better the run

Thats a handsome beast , i may have to take a closer look next time iam on your side of the pond lol. ( i work over that side).

swirl gasket from dealership.

JTDman said:

Thats a handsome beast , i may have to take a closer look next time iam on your side of the pond lol. ( i work over that side).

Click to expand...

No probs!!

Thanks all for replies but still no help on MPG?? 35 is rubbish!

Bio diesel? same effect.

ok regards mpg, it could be a whole range of things... if you have had all your filters and oil changed its not that did you have diesel filter changed... follow your fuel lines and check all the pipes seals and fittings to check there are no small leaks... if that is ok then i would suggest that you recalculate the mpg again just to be sure. if that doesnt work get your tracking tested, and if that fails then i really cant help are your tyres at the full pressure really sorry i cant fully help on mpg but there are so many different things it could be but 35 sounds a bit off you should be hitting 40-45 are you definately sure you have calculated correct..

Yup, ran it on bio over the summer, slightly lower mpg as expected, about 430miles brim to brim (61 litre) = 32mpg

normal deisel I get about 450-460 miles = 34mpg

Hacking me off!!

I'm used to audi 80 estate 1.9 tdi's @ 48mpg

at 35mpg i'd be more inclined to try disconnecting the air flow meter first.

try redex twice if this doesnt change your mpg then i have no more ideas for you as it could be a blocked injector and this should cure it, and trust me it works i have seen it in a demonstration, if your mpg doesent rise after that then i think you are stuck with the poor mpg, has the mpg been like this since you bought the car

yes it could be a problem with maf try that too sorry never picked up on that

OK,

I'll run 2 full tanks with redex in and see.

If the MAF (that's the air-flow sensor right?) is at fault wouldn't it show up when the ecu is plugged in?

If I disconnect it won't I then be in 'limp mode'?

Also if I block the egr valve (supposed to increase mpg) then will this trigger the ecu into limp mode?

I may just rip the ecu out and plumb for 2 twin webbers.... oh sorry, diesel!!

yes its the mass airflow sensor it will bring on the engine management light but not limp mode, or it shouldnt but fiats are weird and wonderful.. obviously if the mpg increases with this disconnected then it is at fault

egr valve blocking has a very minimum if any effect on mpg just keep it clean
when i say minimum i really mean NONE

I may just try that then.
Where is the maf sensor, near the air filter I presume?

I ran on bio-diesel over the summer, will this have cleaned the injectors?

the bio diesel will have done some cleaning but just try the redex to double check..

right the maf sensor is connected to the end of the air filter pipe work on the throttle body, disconnect the air filter pipe and look inside you will see a round disc blocking the airflow move this by hand and give it a good blast with carb cleaner then dry it off with a rag take it for a spin and see if there is any difference or if that fails disconnect and drive as normal for a few brim to brim tests and see what happens