Hi Everyone , I am new to the forum so hope I am posting in the right place , I have just brought a Multipla , previous owner assures me it has had a service , plugs look new , leads etc , also had cam belt fitted , he had problem with missfire which garage changed coil pack , new knock cover (I think its called ) and lots of work done !! Injectors cleaned and so on
After buying the car have noticed it idles poorly , not like it wants to cut out just not at the right place lol and am getting really poor mpg ,trip computer says 17.5mpg , ( I can do 25 miles on a tenner ) , the air hose looks worse for wear and have ordered a new one from fiat , but garage assures me this isnt the problem ??? is that true and if so , where should I look next as have covered all service stuff :bang: The exhaust looks fine and brakes aren't sticking .
Thankyou in advance for any help given

sounds like the cam belt may have been fitted wrong get the timing re-checked

How many miles on the clock? My Punto mpg has fallen through the floor and it splutters, looking at lambda sensor as it's over 100k miles now.

Howmatt

If you have no record of the engine running smoothly ..using the proper fiat (or aftermarket comatible) tools to check the cam timing would be one of my first ports of call.

a duff O2 sensor is usually easy to spot using a live dashboard software and a cheap pc/laptop OBD II interface...i doubt many garages worth they're 'salt' as it were would miss that one.
but compatible O2 sensors like the one i fitted to my wifes 1.6 multi (when her sensor up and died at 67k miles )are cheap enough so its worth a try if you dont have access to a obd software.

also check the induction system for leaks that could upset the mixture ...also you may want to remove the inlet manifold and check the seals ...an air leak here caused my wifes multi to run very bad indeed....easily sorted but had me scratching my head for a while.

another thing i had was despite good servicing repeated clogging injectors (my wife insists on running the car nearly dry and parking on our inclined driveway....not good practice )which was cured by adding a secondary high presure fuel filter to the bulk head of the multi.

Thankyou for your response , the car has started now to rev even thou foot not on accelerator , doesnt do this in idle , just still idles rough , is there anything that can cause both these sypmtoms or are they unrelated , thanks in advance

Throttle potentiometer is a good start, this is an electronic bit that sits above the throttle pedal and tells the ECU how hard the throttle is pushed.

There is a known weak point in the system which is a white electrical connector on the n/s just before the ECU, you need to locate and clean the connector!

Thankfully, this has been posted up before http://www.fiatforum.com/multipla/274961-engine-revving-out-controll-2.html