Fuel Problems - Ford Mondeo

sassy_one

Today after filling up with £30 I managed to get 34 miles from the tank :eek:

Just under a pound a mile!!!!!!

So, now will have no choice but to investigate further this weekend and see whats happening and if need be, book it into the garage for them to have a look at it.

The car is not running rich, but has had battery issues recently.

I started the car the other day and it turned over slowly, since then the on board computer on the dash is reading '- - -' for 'miles remaining in tank.

And when I was traveling home after starting it on Monday very slowly, all the headlights, dash lights all went dim until I was moving 30 MPH+.


I am intending to discount the battery and leave it discounted for a hour so more, to wipe it's internal memory - although this will cause it to run rough for the first 20 miles, I am told?!

Will this reset 'everything' on the computer or just certain things?

Also, could my fuel filter be to blame here?

I mean, a pound a mile - there is something defo that has gone wrong!

Rolandtheroadie

Sounds more altenator than battery to be honest. Once started the alternator should be able to cope with any demands placed on the system.
I may be wrong, but if I am, someone will be along to shoot me down lol.

bigjl

If a car goes through almost a litre permile then it is either running rich or leaking it.

There are no other possibilites.

Or is your problem simply the range on the onboard computer?

The only thing that will happen when you leave the battery disconnected will be any parameters that are altered through usage will be reset to the factory parameters.

The ECU will then relearn and will eventually end up the way it is now.

sassy_one

scotsman4th wrote: »

Sounds more altenator than battery to be honest. Once started the alternator should be able to cope with any demands placed on the system.
I may be wrong, but if I am, someone will be along to shoot me down lol.

Thanks to you both for your replies so far.

The thing is, until Monday I was getting way better MPG than what I am now, since I started the car on Monday to which it turned over slowly as the battery isn't great and I haven't had time to replace it

Last night, I had to put my lights on and as I did, I noticed while sitting at lights all the dash lights were all dim, thought I had my side lights on, but nope, they were on and as I pulled away they all went bright as they are meant to be!

This a side, the clock in the car also keeps resetting sometimes upon starting??

The car doesn't appear to be running rich although I can't smell anything, is there any other way to detect such?

The MPG have got stupid now and I really can't afford a pound a mile LOL

I haven't spotted any leaks after moving the car each morning, but I will check thoroughly tomorrow.

The on board computer is reading '- - -' Miles remaining in the tank, however I know it went empty after £30 went in as the low fuel light came on and the fuel gauge is on empty too.

The car normally admits a beep when the remaining fuel on board reaches 50 miles, then a again at 25 and then when there is only 10 miles remaining in the tank, but that appears to have stopped also?!

I was thinking maybe the belt is slipping? But, I guess this wouldn't prevent the fuel problem?

patman99

Get it along to a garage to have it diagnostically checked.

If it is the charging system, it could by very expensive to rectify as Ford fit a 'Smart charge' system. So a failure in this area could be either the alternator, charge control unit, or the microproccessor on the dash.

If it is either of the last 2 thinks, then you will not be able to fix them yourself as they both need to be programed in to the engine management unit.

sassy_one

patman99 wrote: »

Get it along to a garage to have it diagnostically checked.

If it is the charging system, it could by very expensive to rectify as Ford fit a 'Smart charge' system. So a failure in this area could be either the alternator, charge control unit, or the microproccessor on the dash.

If it is either of the last 2 thinks, then you will not be able to fix them yourself as they both need to be programed in to the engine management unit.

I am intending to book it into the garage that I have used the past few years and get them to look at it.

However, first I am going to try discounting the battery, sticking it on a trickle charger over the weekend and put it back in and see what happens along with this I am going to check for fuel leaks, and to make sure the air intake isn't blocked.

After trying the above things, I will them be taking it to a garage.

If the alternator is at fault, how much is a new one (roughly) and how much for a refurb'd one?

forgotmyname

Dodgy voltages will cause the dash to go into senile mode. Gauges could be misreading.

Simple voltage meter will tell you if its the battery or the alternator. Disconnecting the battery does not
reset the ECU on later Mondeo's. What year is yours? petrol/diesel?

Approx 6mpg?? You would know if it was really doing that, Black smoke from the exhaust, Running very lumpy
especially at idle.

Wouldnt take long to cause serious damage.

Gloomendoom

It may seem a daft question, but how do you know it's using more fuel?

sassy_one

forgotmyname wrote: »

Dodgy voltages will cause the dash to go into senile mode. Gauges could be misreading.

Simple voltage meter will tell you if its the battery or the alternator. Disconnecting the battery does not
reset the ECU on later Mondeo's. What year is yours? petrol/diesel?

Approx 6mpg?? You would know if it was really doing that, Black smoke from the exhaust, Running very lumpy
especially at idle.

Wouldnt take long to cause serious damage.

Yeah - tonight the lights didn't go dim, although when starting it it turned over slow this evening.

I am going to take the battery out at the weekend and place it on a trickle charge and see if I can bring it back to any sort of life.

My Mondeo is a 2000 plate, Petrol and automatic (2.5 V6)

I did some belief volts measurements the other day although not the best as was quick as haven't had any real time, checked it with engine off, then with it at idle and then again at 4000 RPM - volts changed slightly at 4000 RPM.

It isn't lumpy and it's ticking over perfectly, although a spark plug and HT lead is change is due on its service next month.

I today got some Fuel injection cleaner, was £25 from a local car shop, poured it in with another £30 of petrol and appears it may, MAY have cleared what was wrong regards the MPG, although the battery is still touchy.

Will report back more at the weekend once I gain more information for you guys

sassy_one

Gloomendoom wrote: »

It may seem a daft question, but how do you know it's using more fuel?

Because I ran it down till the warning light came on for petrol and then filled up and with £30 it only did 34 miles :eek:

Put some more in today and fuel cleaner and appears to have up'd the MPG, fingers crossed!!

atrixblue.-MFR-.

sassy its going to be the alternator if you had new bat. there is never a brand new starter or alternator unless your car is brand spanking new and had a duff one from factory. they are all recons when you purchase one from motor factors or maindealer, they charge a surcharge on purchase refunded when your old faulty one is returned, that will be sent back to their supplier for recon then re ditribution (recycling effectivly).

oh and 2.5 v6 has 2 ecu modules. one under bonnet and one under passenger side wing! when one goes it trips the other out. air mass meters, and map sensors can effect MPG if one or the other is down.