drink problem

[Noesph]

I'm getting fed up with my car.

It's a twingo gt (40k with fsh). Had it about 7 months now, done about 3k in it.

Problem is around town it gets about 25mpg and on the motorway it gets around 30mpg. I'm not driving like a need a pee all the time. (say 85% of the time I change up around 2500, 3000 rpm). The car has been fully serviced, all filters and oil changed to renault spec and the brakes readjusted to make sure there not dragging. The car has no error codes and runs ok (well, I do I think it should have more go than to does though, long term fuel trim is around -9%) and passed its mot no problem. It's been to 3 garages and no one can find out whats wrong with it. Coolant and air temp sensors are ok.

As an example I had a peugeot 106 1.1 for 7 years, doing the same journeys, it never went under 38 mpg and on the motorway it was doing high 50's.

I like the twingo, but its a joke that a 1.2 is going through fuel like a 3 litre. So I thought I'd ask on here for any ideas, otherwise it'll be going soon, I'm losing heart in it .

 

[jra3d]

That's the sort i would get from my RS, something doesn't sound right!

Sure oscar or Neil may have ideas

 

[oscar]

Noseph these obd2 readings aren't accurate whatsoever when it comes to fuel trim, i'd completely disregard them. what i mean is that the engine management isn't intelligent when it comes to fuel monitoring, it can only increase or decrease fuel according to lambda and MAF sensor readings etc. the best way to accurately guage exhaust gasses would be to stick a prong up her back side lol, that will tell you lots of things such as wether or not the cat is working accurately which is the sort of area where OBD diagnostics become useless and real diagnostic skills come in. the causes of this could be a split vacuum hose, the car will be drawing in unmonitored air whilst the lambda sensor picks this up it will tell the fuel management to inject more fuel and will constantly alter an overly rich mix which the post cat lambda sensor will constantly be picking up. take your spark plugs out for me and send me a picture of the tips will you? this will be a good starting point to judge the fuelling

 

[singlespeed]

Didn't you find the turbo plumbing all bodge to make it go woooosh on the cheap? (Apologies if not). Wondering if the plumbing is now all correct, or if its had a rubbish remap in the past

 

[Noesph]

It wasn't right (It had a forge, or a copy of a forge, dump valve but it was fitted wrong , there is a thread somewhere) but its all been put back to original spec by renault a while ago.

Spark plugs where changed about 2 weeks ago, but I still have a old one sitting in the kitchen. I don't know how long they were in though, had to put wd-40 on them to get them out.

I'll have a chat with the mot center down the road tomorrow morning to see of they will do a emission test with a print out.

 

[oscar]

it would deffinately confirm that the problem is on the air metering side or ignition side of things, if you're patient and handy with a multi meter then we could figure this one out lol. won't need to do an emissions test now that we've seen the plugs, it would indicate a rich mixture but the plugs are still appear to be working fine like #7 on the picture above. curiously the plugs you showed me, can you tell me the part number of the plug? should be on the plug itself mate?? also you mentioned fuel trim levels etc, so you'll have some form of diagnostics machine correct? can you check through the parameters open to you and cross check them with below?

TUNING AND EMISSIONS

Ignition timing - basic BTDC (degrees) Engine / RPM : Not adjustable
Ignition advance checks (degrees) Engine / RPM : ECM controlled
Idle speed RPM : 650 + 50 not adjustable
Oil temperature CO test Degrees Celcius : 80
CO level at idle speed - tailpipe Vol. % CO : 0,2 max not adjustable
HC level at idle speed ppm : 100
CO2 level at idle speed Vol. % CO2 : 14,6 - 16
O2 level at idle speed Vol. % O2 : 0,1 - 0,5



SPARK PLUGS

Spark plugs Original equipment : NGK
Type : ILKAR7A7
Electrode gap : 0,6 - 0,7 mm

 

[Noesph]

They are NGK ILKAR7A7, new ones are the same. I have touchscan, I post what is says tomorrow.

 

[Noesph]

Diagnostic Report.

I went for a 20 minute drive, then plugged the laptop in and let it idle for about 10 minutes to get the data.

https://www.dropbox.com/s/k2joh0digw1gymi/Diagnostic Report twingo.pdf

The Freeze Frame never changes.

It does report a misfire though.

Service $06 - On-Board Monitoring

Component Description Value Minimum Maximum Units Result
$01 - Exhaust Gas Sensor Monitor Bank 1 – Sensor 1 TID $0A - Sensor period (calculated) 0.24 0 1.504 sec Pass
$21 - Catalyst Monitor Bank 1 TID $0A - Sensor period (calculated) 765 0 7650 counts Pass
$81 - Fuel System Monitor Bank 1 TID $84 - Manufacturer Defined -327.67 -327.67 -327.67 % Pass
$81 - Fuel System Monitor Bank 1 TID $85 - Manufacturer Defined -327.67 -327.67 -327.67 % Pass
$A1 - Misfire Monitor General Data TID $86 - Manufacturer Defined 8 0 65535 Pass
$A1 - Misfire Monitor General Data TID $87 - Manufacturer Defined 0 0 65535 Pass

 

[oscar]

fuelling and whatnot seems fine, ignition dwell periods in range too and deffo seems to be making spark. what was the code for the missfire exactly? for example ''p0303'' ??

have you noticed any unusual blue or white smoke in the exhaust, or a strong smell of unburnt fuel (like you always smell when a bloody jap / super car passes you) ? really need the code itself for the misfire before we can start to look at certain things

i've the damndest feeling that it's going to be a problem with the HT leads or coil pack. do you have a multimeter at all or insulated wooden tongs to run a quick check on it??

 

[Noesph]

no code, It just comes up on the On-Board Monitoring, 8 misfires on the misfire monitor but it's within range / not bad enough to throw up a code.

I do have a multimeter lying around somewhere.