General Low MPG

[panda1408]

I've just filled my Panda up and as you can see from my sig I'm only getting around 30mpg average, I'm just wondering what people thing of this, I was expecting more like 35?

I only do short journeys mainly, and I do like to put my foot down abit sometimes I know this wont help and the snow wont have either but still it seems abit low doesnt it?

I've noticed that sometimes when idling the revs will dip and rise quite alot, it almost stalls sometimes and also when I do put my foot down abit or go to pull off when its cold it will splutter and die for a second. I thought about doing an ECU reset to see if it makes a difference but I've also read that it could be the lambda sensor that is the problem?

 

[CLXCraig]

Have the same problem in my CLX. when you start up from cold let it idle for about a minute and dont boot it for about 5 minutes. low mpg will be down to driving with a cold engine caused by not letting it warm up and also the cold weather keeps the ambient temp down lower than normal. get a for sale sign and cut a bit of it off and put it over half the rad, will help get the temp up quicker and you'll notice some differences.

 

[panda1408]

I already make sure I don't rev it too much for the first few miles of driving, as I know that it wont do it any good, my temp guage seems to sit at about 70 whilst going along, which is abit low, could it be my thermostat? I'll get something to cover the rad with anyway, whats the best way to hold it on?

 

[lewey]

shove in front of rad behind grille. You'll find it easier with some gaffer tape perhaps. Thermostat is cheap and good to replace if you haven't looked at it for 5 years, regardless of usage. Even when good, you'll run a little low when very cold and has a big effect on economy. Other obvious things are air filter needs to be clean and oil changed regularly. It is certainly possible that you have a lazy lambda sensor, but if it was bad, it would have shown up in the last MOT unless it is a very recent thing.

Other than these, driving short distances and occasionally hard is going to equal moderately bad economy in any car I'm afraid!

 

[lightweightmick]

I've fitted two pieces of cardboard (box from Aldi ) to the 4x4 - either side of the bonnect catch and slipped down between grill and rad. I find that if you fold the top edge over it gets held in place by the bonnet stay when stowed - I've done this with the CLX too as I mainly do short runs - hope this is useful
oh, if you do runs over 3-5m you might find you'll need to cut a hole in front of the rad fan, or on longer runs (over 10m) just pull out the piece in front of the fan and store it behind the driver's seat

 

[panda1408]

Thanks for the replies everyone I'll try blocking off the rad on thursday and I'll see what difference it makes to the temp, I'll check the thermostat if its still abit cool. Think I will do an ECU reset aswell as the previous owner said it stopped the overfueling problems he had. Other than that I'll just try driving with a lighter right foot and hope that the MPG goes up abit, I'd be happy with around 33-34 really.

 

[Chas Uno]

I've noticed that sometimes when idling the revs will dip and rise quite alot, it almost stalls sometimes and also when I do put my foot down abit or go to pull off when its cold it will splutter and die for a second.

This could also be the infamous distributor vacuum diaphragm failing, if your car has one fitted that is.

As for 70 degrees on the temp gauge, I think that's approximately when the thermostat starts to open. Therefore with the outside temperatures being so cold the engine is being cooled more than usual even before the thermostat is fully open thus the low running temperatures.

Your average mpg does appear on the low side though! My Uno with the less efficient Lampredi 1300 engine and twin choke Weber carb is averaging almost 34 mpg even in this cold weather!

 

[lewey]

This could also be the infamous distributor vacuum diaphragm failing, if your car has one fitted that is.

The car is a late injection model with coil pack, distributor diaphragm bit is not relevant in this case, but a good shout on a an earlier model.

 

[Most Easterly Pandas]

Looking outside the box. Freddy, is your speedo recording correctly? If under recording mileage you'd be getting a low MPG figure.

 

[CLXCraig]

The car is a late injection model with coil pack, distributor diaphragm bit is not relevant in this case, but a good shout on a an earlier model.

its an inbetweener lewey. these still have a distributor on the end of the cam so chas' call still stands

 

[lewey]

its an inbetweener lewey. these still have a distributor on the end of the cam so chas' call still stands

Cheers Craig. Must be an early 93. Ignore me Freddy.

 

[CLXCraig]

now where is he to explain his idea!

 

[panda1408]

Looking outside the box. Freddy, is your speedo recording correctly? If under recording mileage you'd be getting a low MPG figure.

The speedo seems spot on when I checked it using one of those road side speed displays so I dont think its that.

Cheers Craig. Must be an early 93. Ignore me Freddy.

It is indeed an early 93, February I think.

 

[Most Easterly Pandas]

The speedo seems spot on when I checked it using one of those road side speed displays so I dont think its that.

WOWOWOWOWO :idea:

That could well be it!

Panda's in whole tend to over-read by about 8-10%

Now as to if this means that the mileage is over recorded also is another matter, but with it being a cable driven analogue system, if your speedo reads a correct speed in comparison to other reading 8-10% more then perhaps, if trying to compair your MPG to other Panda's you need to times it by 8-10%

Perhaps I'm looking into this in far to much detail

Jon.

 

[lewey]

I think you have a point Jon. These cars can over read quite a lot, especially if you fit cinq wheels and tyres or something. This tends to make older cars look better than they really are as modern odometers are killer accurate, even if the speedo isn't in some cases. When I measured my MPG with an original analogue speedo I had for a week or so, I was well into the 50s. Although it is a lot colder, I am now finding 43 on a run, just because I have a properly calibrated digital odometer!

One other thing I thought of was if you are brimming the tank for the sake of working out MPG, do you have leaky filler pipes or seals on top of the tank perhaps? You probably would smell it, but you might have got used to it?

 

[CLXCraig]

I had a problem were i was going througha tank ina week for about a month. thought it was just me till i smelt the petrol in the engine bay. pipe hand split with age and petrol was spraying onto the airbox and dizzy. god knows what would have ahppened if it hit the exhaust! check it out though. mine split on the pipe from the small filter bolted to the inside of the n/s wing and the "in" to the TB. cheap fix as it only costs about a 5er for a meter of fuel pipe

 

[panda1408]

I'm pretty sure there aren't any fuel leaks, I'll have a check though as you never know. Interesting idea about the odometre, although I'm not sure because I'm surely not the only person who has an accurate speedo.

Was able to sort out a cover for the rad or do an ECU reset today because my Dad had to use the Panda to go to work as it was the only car he could get out in as my Mums car is useless on snow and ice and his land rover had got stuck on a snow covered grass verge.

My dad filled the Panda up again and it has only done about 25mpg in the 40 miles it has done since I filled it up

 

[lewey]

My dad filled the Panda up again and it has only done about 25mpg in the 40 miles it has done since I filled it up

My V6 Alfa 166 averages more than that. Unless your crawling through London traffic all the time, there certainly is a clanger of a problem somewhere.

 

[lightweightmick]

I think it would be a good idea to post resistance readings of the temperature sensor on the manifold. This 'tells' the ECU how much fuel is required - if it's faulty it can read low and result in too much fuel being delivered to the injector.
I had this problem with mine (CLX) drinking fuel and fitting a new sensor (£8-10) cured it.

 

[CLXCraig]

Thats really poor. Have you got fuelly set up right?

apart from a fuel leak or a duff sensor somehwere i see no other possibility