GTI6 16mpg?

[KevinTW]

25mpg I could live with but not 16.... It is not a Dodge Charger. I don't drive it hard but it does a lot of 5 mile trips. It is bad on a run too. I have changed the oil and filter, the tyres are pumped to 35psi and the brakes don't bind. It has a K N cone filter I would like to put back to standard when I find an original airbox. Would this help?The CAT is new and there are no warning lights on the dash. I am thinking lambda. Is this something I can test? What else could be contributing? The car is a 1997 R reg  110k which runs smoothly and does not smoke.
Thanks Kevin

[Eeyore]

must be a sensor. How is performance? Does it idle rough?

[KevinTW]

must be a sensor. How is performance? Does it idle rough?

Accelerates nicely,runs and starts well ,idles smoothly. Smells of petrol from cold

[Eeyore]

i guess lambda would be a good one to go for. anything in the history about it being replaced?

[KevinTW]

i guess lambda would be a good one to go for. anything in the history about it being replaced?

No history unfortunately. Lambda is worth a punt I suppose. Is there anything else I should look at? I could wash the K and N . Change  Fuel filter? Would an original airbox make a difference and has anybody got one?

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i guess lambda would be a good one to go for. anything in the history about it being replaced?

No history unfortunately. Lambda is worth a punt I suppose. Is there anything else I should look at? I could wash the K and N . Change  Fuel filter? Would an original airbox make a difference and has anybody got one?

And I just put injector cleaner in it.

[DeeTurbo]

Have you checked if the filler pipe elbow is leaking?

[KevinTW]

Have you checked if the filler pipe elbow is leaking?

I have never seen any petrol on the ground but I will check again in daylight. I have just washed the cheap cotton induction filter too.

[RetroPug]

My first bets would either be lambda or the green temp sensor on the thermostat housing.

I am fairly sure that when the green temp sensor detects the coolant is cold the car runs rich, and that if the sensor is faulty/unplugged then the car will just run rich all the time.

Frankly, at the age they all are, most sensors are either not working 100% or will be failing at some point in the near future if they are original so it is probably worth replacing both if you intend to keep the car for a reasonable length of time. That's just my opinion though.

[welshpug]

very common on SC cars to have wiring issues as they need to be modified due to the relocated components.

[KevinTW]

My first bets would either be lambda or the green temp sensor on the thermostat housing.

I am fairly sure that when the green temp sensor detects the coolant is cold the car runs rich, and that if the sensor is faulty/unplugged then the car will just run rich all the time.

Frankly, at the age they all are, most sensors are either not working 100% or will be failing at some point in the near future if they are original so it is probably worth replacing both if you intend to keep the car for a reasonable length of time. That's just my opinion though

Thank you. £10-49 in Euro Car Parts. There was voltage at the plug when I put the ignition on. Just going to get it. Lambda ordered,air filter washed and dried,injector cleaner in the tank. Can anybody think of anything else?

[BiG K]

Cars don't really do great with lots of short, start stop journeys but 16mpg is a bit low! If the fuel filter hasn't been changed, then you should anyway, as it will be due replacement being 16 years old!

Do these engines use HT leads? Have you checked the spark plugs?

[insomaniac45]

i know its not a gti, but my 2.0l cabby is god awful on the school run for Mpg.

If it is just the school run i am doing, then i expect to get at most 70 miles to £20 of fuel, (current prices around 115ppl) which gives me - approx 18.4mpg

now if i were to do an almost pure motorway run, on £20 i almost get 120 miles at a cruise of 60-65mph. - 31.4 mpg roughly. not far from double my original mpg. and i am sure, if i were to give her a full service, (as im not far from needing one according to mileage) and hitting it with all the cleaners, i could prob get that up to about 40mpg on the motorway.

[puggered]

i know its not a gti, but my 2.0l cabby is god awful on the school run for Mpg.

My cab was shocking with the original engine as well (28mpg was the best it could do)
With the gti engine it's 40mpg with an auto box.

[insomaniac45]

i know its not a gti, but my 2.0l cabby is god awful on the school run for Mpg.

My cab was shocking with the original engine as well (28mpg was the best it could do)
With the gti engine it's 40mpg with an auto box.

nice

if the current engine in gem ever lets go to the point of no return, i will prob go with either the S16 or to the dark side.............

[KevinTW]

i know its not a gti, but my 2.0l cabby is god awful on the school run for Mpg.

My cab was shocking with the original engine as well (28mpg was the best it could do)
With the gti engine it's 40mpg with an auto box.

nice

if the current engine in gem ever lets go to the point of no return, i will prob go with either the S16 or to the dark side.............

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Just spoke to the 306 guys in Thetford. Apparently  non genuine green temperature senders can read wrong and cause over fuelling. Also check the fuel pump relay on the back of the battery box is not cracked or missing its top. That will screw up the mixture if water gets in. Mine is fine unfortunately.

[DeeTurbo]

Try measuring the resistance on the coolant sensor with a multimeter.

http://www.306oc.co.uk/forum/attachment.php?aid=26015

Where are you based?

[KevinTW]

Try measuring the resistance on the coolant sensor with a multimeter.

http://www.306oc.co.uk/forum/attachment.php?aid=26015

Where are you based?

Thank you I will give these a go. I am in Tunbridge Wells. Worked on cable tv in Dunstable 20 years ago.

[Matt-Rallye]

I used to average 16mpg in my Rallye which was same spec as yours is described but that was with a fairly hefty right foot and all b-roads.