Technical Rough idle , low mpg

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Technical Rough idle , low mpg

5APPH1R5

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Hi Everyone , I am new to the forum so hope I am posting in the right place
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, 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
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The exhaust looks fine and brakes aren't sticking .
Thankyou in advance for any help given
 
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I am having the cam belt checked for that today , just worried that if thats correct where to go next ? Can the lamba sensor be checked or is it just replace and hope? and do you think that is more likely than the maf sensor ?? Thanks in advance
 
OK just heard from the garage apparantly they need a special tool to check the cambelt , which they haven't got , have rang Fiat and they want £200 to check it :( , garage checked maf sensor it is fine , and no faults on ecu
:bang: would the lamba sensor show a fault if it was faulty ? just need the car to run better fuel wise as going on hol (n)
 
I'm not certain if lambda would throw a fault in all circumstances.

I'd leave that garage straight away if they need a tool to determine that.
Can you bring it to garage that did the belt?
Marty.
 
no can't take it to the original garage it was done by previous owner and miles away (n) , cambelt has now been checked by a different garage and is fine , took it for exhaust check and there are small holes in it ,but emissions are fine ?? thought if it was bad enough to cause rough idle it would fail emissions ?? could this be causing these symptoms or is it defo engine related , someone also suggested fuel blockage ?? have also bought new air filter hose to try , all sensors are fine , could just scream lol
thanks in advance for any help :)
 
Have you had codes read yet???
Really could be a multitude of things, coil pack, leaky manifold, loose hose etc
Doubt it's a fuel blockage given your mpg.
Marty.
 
If you disconnect the MAF, the ECU will go to a default value which won't do the car any harm but will eliminate the MAF if it's values are way out.
Same with the Lambda sensor, but not sure as I run a diesel.

Where abouts are you? Someone might be able to recommend a good mech/indy, at your mileage it might be cost effective.
 
right to clarify , car has had new plugs, new leads, new coil pack , injector replaced and injectors cleaned , also ha ecu repair ( don't know why) !! maf sensor and lamba sensor have both been checked and are fine , emmisions are great , new cam belt , diagnostic check (codes?) finds nothing wrong with the car , exhaust is fine and brakes not stuck on , car idles rough ticking over at around 650rpm and is drinking petrol on idle like no tomorrow :( , watched the mpg go down from 22.9 to 18 on tickover ,( doing slightly better on fuel after changing leads ) still trying to find someone to check cam belt timing as could be out a notch ,( found out garage only did a visual check and really want it checked properly ) I live in Dudley West Midlands so if anyone knows a good garage that won't charge the earth ?? much appreciated , car has also had compression test which is fine , it makes a low tapping noise but have been advised this is common with the multipla?? also been advised by a diff mechanic that it could be fuel blockage again although fuel pump as also been checked , as it has been drinking petrol it could have sucked stuff up off the tank if petrol got to low ?? ( not me) I keep it topped up . air hose has also been replaced now just don't want to keep throwing money at the car and not find the problem (n) Thanks in advance for any help given
 
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car is now 'chugging' I know its a long shot but could all this be battery/alternator related? I had a vauxhall zafira that had a bad battery and it caused similar probs , also does the car start 'chugging' if low on oil? as the zafira did this too ? have checked oil and its just showing on the dipstick but the zafira would start doing this and show oil too , thanks in advance
 
Try using (or borrowing) a multimeter and check the battery, 12-13v minimum.

Start the car up and check again with the car at >2k, should be getting at least 14v, you should see the volts increase if the engine is blipped.

Did you disconnect the Maf and the Lambda and did it make any difference.
 
haven't got a multimeter but noticed the battery terminals are quite dirty , gonna clean them tomorow and take the car for a battery check ( so this could be the problem?) maf sensor was disconnected caused a code on the ecu ( so think the ecu is working fine ) but made no difference to the rough idle , lamba sensor has been visibly checked and had an emmisions test done ( was told it would fail if sensor was knackered?) thanks for your reply
 
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