Technical JTD MAF 'issues'

[ABZSTILO]

I've been having some odd power losses and 'flutters' from my JTD of late. Initially I put it down to the cold conditions but as the timing belt was close to being due for replacement I decided to put my car into FIAT for the belt change and service (ouch ) which I hoped might sort it out. I mentioned to the service manager that I was experiencing an occasional flat spot or 'flutter' from the car. However when I got it back the diagnostics checks showed naff all wrong with the car and apparently it didn't show up on a road test either But trust me the problem remains, it's intermittent but there enough of the time to irrititate the hell out of me

Now I've been flicking through this and other forums and I'm now convinced that the symptoms my car is showing are indicative of the MAF sensor failing.
I've read with interest the piece in the punto section about replacing/cleaning the MAF https://www.fiatforum.com/punto-guides/129316-1-9-jtd-maf-sensor-cleaning-replacement.html
Very useful wee guide that
Sadly I've not the facilities or all the tools required to do this in the dry at home so it's going to have to go into my local garage for a 'MAF clean' but I suspect I will have to replace it

Have any other Stilo JTD owners changed their MAF sensor? If so where'd you get it and how much did it cost? I've been looking around (as you do) but nothing beats 1st hand experience

I need the car to be spot on for it's long run down to Watford in a fortnight and a bits time

 

[Argonought]

Just disconnect it and that should prove it one way or the other.

It that cures the 'issue' then I'd recommend www.shop4parts.co.uk

It can be a fairly simple 30 minute job (if done before) but if doing it for the first time then I'd recommend a good check, strip down and clean of:

1. Breather pipe to turbo housing
2. Rubber turbo housing (between MAF and turbo)
3. Oil drain pipe to oil/vapour trap box (under air filter)
4. MAF sensor

At this point it's dead easy to fit a new air filter which I'd recommend you do.

Now put everything back but make sure you've got access to say a Halfords store as you'll need 3 new jubilee clips to replace the Fiat originals you've taken off.

That's why it's a lot easier the 2nd time you do it!

 

[ABZSTILO]

Time and facilities is the issue for me now - so it's getting bunged off to my local garage on my next days off.... I suspect I'll just go straight to replacing the MAF although cleaning it might produce the results I reckon it's a temporary solution if it's on the way out.

Jings - more expense just when I didn't need it

 

[Argonought]

Time and facilities is the issue for me now

30 secs to open bonnet and remove the connector

You're look pretty silly if it's exactly the same with a new one :bang:

 

[ABZSTILO]

Sadly I couldn't get the connector off with my shovel hands in the freezing weather at the 1st attempt - however I have some time on monday and, if the weather is fine, will try again before it goes to my local garage for further diagnosis.
Whilst I'm convinced it's a MAF fault/issue I'm not daft enough to buy it on a whim..... but it is good to cover your bases when it comes to buying and I'm 'stealing' myself in preparation for more expense
Very irritating fault, not a flutter at all this morning on the way to work but when I nipped out for some fuel...... well, leave it to your imagination

 

[Argonought]

You must press the two prongs, at each end of the plug, together to release it (press quite hard) but DON'T use brute force to pull it off.

Quite hard to do at first but much easier when you get the knack.

I disconnected mine on the A13 outside of Paris recently (for a mpg test). Took about 30 secs in a Picnic area.

 

[ABZSTILO]

Achieved (good tip that about the clips) on a coffee break from work - so when my lunch break comes around will take it for a spin and see what happens.......

 

[ABZSTILO]

Quick blat around the block with the MAF disconnected and......... in slow/mixed traffic for 5 minutes up to 40mph ..... no spies - not one. Seemed to run fine without any juddering/missing or flutters

Sooooooooooo.... looks like another new bit needed

Will try it on the 37 mile run home tonight and see how I get on :idea:

 

[ABZSTILO]

It ran fine all the way home with the MAF disconnected - weird

So new MAF sensor is indeed - bummer

 

[minimad99]

Abz,
could you elaborate a bit on your symptoms?
I'd like to hear more so i can see if i could have the same problem.

Ta.

 

[a1ant]

It ran fine all the way home with the MAF disconnected - weird

So new MAF sensor is indeed - bummer

Hi mate,

May be worth giving it a clean first, as 95 times out of 100 that will sort it for another few thousand miles. Might save you the £150 or whatever it is these days. And if you do go for the new option, dont go for a cheap no named one, as from experience, these tend to fail very quickly.

Hope that helps,
Alan

 

[ABZSTILO]

Abz,
could you elaborate a bit on your symptoms?
I'd like to hear more so i can see if i could have the same problem.

Ta.

It's tricky to summarise but it creeps up on you.... a certain amount of hesitantcy under acceleration, feels like a dirty great flat spot which suddenly goes and normal service resumes. Not a constant - sometimes happens when the cars hot, very often happens when cold and sometimes goes for a day or two with nothing happening. Car feels a smidgen down on power but it's difficult to put your finger on it, noticeable amount of smoke when it 'clears' particularly when cold. Diagnostic check shows nothing and test drive by FIAT tech apparently no problem. Initially I put it down to some naff fuel which clearly it wasn't

I guess you should just disconnect it like I did and see if your problem also 'vanishes'.

 

[ABZSTILO]

Hi mate,

May be worth giving it a clean first, as 95 times out of 100 that will sort it for another few thousand miles. Might save you the £150 or whatever it is these days. And if you do go for the new option, dont go for a cheap no named one, as from experience, these tend to fail very quickly.

Hope that helps,
Alan

Cheers Alan - I will try the cleaning route first myself if I can get the b*gger off But my free time is running out..... I need a fast solution and if it means spending some spondoolies I might just have to bite the bullet

 

[Argonought]

It might be worthwhile using a bit of contact cleaner on the connector and reconnecting the MAF before paying to have any work done.

 

[a1ant]

There is a guide to cleaning the JTD MAF in the punto guides section.


Alan

 

[ABZSTILO]

Legged it up to my local garage and we bunged it on the diagnostic machine.... interesting. Obviously with the MAF sensor disconnected I had two errors showing, but interestingly the car ran fine.

So we reconnected the sensor to see what was what. I don't remember the exact figures but acceptable limits for the MAF were something like 230-460mg/s and my readings were between 280 and 570 mg/s...... with a mean of 490 so well outside the upper limits.

Naturally we checked the sensor was getting the right amount of voltage etc and it was spot on. So we cleaned the sensor and bunged it back in. Result, sadly, was almost exactly the same The average was still comfortably over the upper "acceptable" limit but lower than previously. To be safe a new Bosch unit is on order and should get fitted on Friday.

Oddly the car ran perfectly on the way home with the MAF re-connected but I'm happy now I've been through the whole process and we know, for sure, the MAF needs replacing. Roll on Friday.

But here's the thing that bugs me. This has been a problem on the car for a while and I was quite specific about getting the MAF checked out when the car went into Fiat for its major service (that's another story ) and cambelt change - I was told it was fine. Presumably they could have done the same checks we did with the diagnostic kit available at a main dealer so as I see it these are the only plausible answers:

1. It simply wasn't done - if it had they would have found what we did today.
2. I was lied to as they forgot to do it.
3. They didn't check the MAF alone but did a generic sweep (that work?).

Very annoying, I think I might have to have words with the service manager.

Oh well, at least I'm happier now

 

[Argonought]

Legged it up to my local garage and we bunged it on the diagnostic machine.... interesting. Obviously with the MAF sensor disconnected I had two errors showing, but interestingly the car ran fine.

That's interesting :chin:

Are you saying that Examiner picked up two engine fault codes or are you saying it just found two problems?

So we reconnected the sensor to see what was what. I don't remember the exact figures but acceptable limits for the MAF were something like 230-460mg/s and my readings were between 280 and 570 mg/s...... with a mean of 490 so well outside the upper limits.

I think this is very much a grey area. When is something faulty and when is it not - as clearly it's doing something. Someone who loves performance might prefer one MAF sensor over one which might give great economy and vice versa.

I think a test comparing a new sensor against the existing one would have been more useful.

Anyway - hopefully you'll still be happy after Friday and at the very least be getting improved mpg

 

[ABZSTILO]

That's interesting :chin:

Are you saying that Examiner picked up two engine fault codes or are you saying it just found two problems?

Two fault codes - P00101 and something like it. Essentially their descriptions were for air intake temperature and no measurable airflow. Both of these functions being run by the MAF which, until we plugged it back in before connecting the diagnostics, had been disconnected for 24 hrs. As an aside I assumed you'd get a dash warning (let's face it, pretty much anything else wrong and it lights up like a Christmas tree) with the MAF disconnected but it didn't happen.

I think a test comparing a new sensor against the existing one would have been more useful.

Funny you should say that The boys at the garage and I discussed this today are planning to do just that on Friday I'm sad that way, but I want to know

 

[Argonought]

Two fault codes - P00101 and something like it. Essentially their descriptions were for air intake temperature and no measurable airflow. Both of these functions being run by the MAF which, until we plugged it back in before connecting the diagnostics, had been disconnected for 24 hrs. As an aside I assumed you'd get a dash warning (let's face it, pretty much anything else wrong and it lights up like a Christmas tree) with the MAF disconnected but it didn't happen.

Entirely normal NOT to get a dashboard error but the fault codes are bad news for me

I've known my Stilo is not OBD compliant since the end of last year but it now seems I can't read fault codes either :bang: (funny enough, the very reason I disconnected my MAF in the first place was to generate a fault code so I could then read it) So it looks like I'm going to be forced to make a visit to my friendly local Fiat specialist and get Examiner connected.

I've been fighting poor fuel economy for some time now and I'm starting to wonder if all those stored errors might have an effect :chin:

Think I'll take your route and pay for an hour on the machine and see what it can come up with

Funny you should say that The boys at the garage and I discussed this today are planning to do just that on Friday I'm sad that way, but I want to know

you sound just like me then

 

[stilosporting]

so when you say try and clean it with contact cleaner, what cleaner are you referring to? i want to get some but want to make sure its the right stuff.