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MG MGF Technical - Urgent Help Please - dead car

Your ideas with this would be much appreciated.
I presume that I ran out of petrol as my car died without warning whilst driving (I know, please don't lecture me but I thought there were still a few miles left in it...) We put in 5 litres of fuel but were unable to get it to start. As the battery then started to fail, someone whos knows alittle about cars connected a battery pack and we tried again and again.... he checked the fuel cut off switch and the fuses but could not get it going. Got the car towed home so it's now sitting there - dead.
I am hoping that someone might know of anything simple and obvious that is stopping it from starting. (I ran out of petrol a few years ago and had no problems getting it going again). My mechanic is not based locally and I am unable to contact him and I am hoping to get it sorted out this weekend!
A couple of facts in case they are important:
When it stopped I immediately tried to start it several times
The fuel gauge is not registering at all, whereas it normally does when engine is not running.

Does anyone have any brainwaves please before I have to call in the expensive experts?

Many thanks


B O'Mahony

Put more fuel in and try again
Ian Walker

Any lights operating? Maybe a dead battery?
Does the starter motor turn at all?

Ian - OK I'll get more fuel and try again.

Dot - yes it was turning over brilliantly and all the usual lights come on. We tried turning over so many times that the battery did almost die, just enough left to alarm it until the battery pack was connected to turn it over again. Since I got it towed home I haven't touched it, but the lights were on during towing, closed the window OK and it locked and alarmed OK so I guess there is still some life in the battery, though that may quickly disappear once I start trying it again.

B O'Mahony

The reason I think that you'll need more fuel is that the tank is saddle shaped so the fuel you put in might not be accessible to the pump. You might have an air lock in the fuel line too but if you put more fuel in it should clear OK and start after a fair bit of cranking over! Try and use Jump leads with the donor car running at 2500rpm to provide the extra better oomph!
Ian Walker

The battery is almost certainly empty (if it wasn't before it is now). I agree that jump leads should be your first try - if that works give it a good run around to try and charge the battery a bit (lights etc off!).

Right I'm off to the garage to get some fuel. Fingers crossed, this is all it needs. I'll let you know tomorrw, thanks.
B O'Mahony

It is my understanding that dregs gather at the bottom of tanks. Thats why you should always top up before it gets too low. Could it be that all the dregs have bunged up the fuel filter?

>>It is my understanding that dregs gather at the bottom of tanks. Thats why you should always top up before it gets too low. Could it be that all the dregs have bunged up the fuel filter? <<

My thoughts exactly GJ. Swap the fuel filter for a new item and see how you go.
Rob Bell

It's only the floating dregs that are a problem when the fuel level is low, as the fuel pick-up is always at the bottom.
George B.

Well I put another 5 litres of fuel in and it started first time! I was very relieved as I thought I may have done some unknown damage.
The only odd thing was that when I tried to fill up the tank at the garage it was difficult to fill (cutting out) and would only take about 3/4 tank even though the petrol was right up to the entrance as if overfull. I guess there may have been some sort of air lock at the entrance to the tank.

Anyway it is running fine and the weather is lovely so I'm now happy.

Thanks to all (especially Ian) for responding to my message.
B O'Mahony

It's happened again! ran fine for a few days then tonight experienced loss of power, fuel gauge dropped into the red and when I attemted to fill up I couldn't get more than 5 worth of fuel in it. The gauge is now registering completely empty and it won't start. Any ideas appreciated

B O'Mahony

The fuel gauge could drop into the red (I think) if the voltage in your electrical system dropped. If the voltage drops then you may be getting a misfire from poor ignition. Perhaps your alternator lead has come adrift at the alternator. Or perhaps a bad earthing problem, but less likely. Does the battery appear to be charged OK? Does the starter turn it over OK?

I had my alternator lead come adrift and because it was making intermittent connection it took some time for the battery to become discharged. In the mean time it produced many weird symptoms, one of which was a variation in indicated coolant temperature. Another was a variation in the brightness of the headlights. If the altenator lead had touched the body work, or engine, it could have meant a burnt out car!

Have the voltage checked

Bruce Caldwell

Is it possibly an airlock somewhere where the feul is measured - not sure how this is done?

The car turning was over fine but after the "running out of fuel" incident" last week the battery may not yet be charged back to as high as usual.
The fuel gauge was not even in the red - it dropped off the scale completely - same as last week.
Is the alternator easy to locate? (Internet access and car/manual/home are not same location!)
Thanks for your advice.
B O'Mahony

First work out how many miles you have done since the car was last filled and cross reference against the amount of fuel you managed to get in. If your running around town only then perhaps 30mpg as an average should be used to estimate how far you have got. 35 to 37 if your doing longer journeys. I suggest that you have simply run out of fuel again.

It is clear to me that you have a very inaccurate fuel guage and your relying on it's reading - don't! If you follow Ian' simple tip from the previous incident and this time add 10 litres and it styarts then you have a problem with the guage and or tank/filler. Filler pipes can become twisted and be very restricted to allowing fuel in. If severley twisted then this may allow airlocking to hold fuel at the neck giving you the impression of a full tank. Whatever it seems clear that your problems are fimrly rooted in the tank area.

The alternator is an efficient 85amp output unit that will be able to provide a rapid charge of the battery within a relatively short period. Certianly a run of 50 miles or an hour plus will have pushed the battery back to a very good state of charge. That is if it is not old and will have reacted badly to being flattened.

The alternator is at the front of the engine, exhaust manifold side which is essentially immediately behind the drivers seat (excepting that the fuel tank sits betwen the passeneger compartment and engine bay) Access is gained by unclipping the hood to screen clips to release hood tension. Then in the back unclip the five spring clamps holding the rear hood rail to the body. Ease the rear of the hood away from the body ensuring that you carefull ease the rear window so it doesn't crease. Secure the rear hood rail in the vertical position with a bungy strap or simialr soft retainer. Now remove the carpet and sound insulation from the engine cover. Remove the 11 10mm headed bolts and ease up the engine cover. Standing atr the drivers side look down to the right og the engine bay and note the alternator is next to the ehaust manifold heat shield covers. The connections are on the exhaust manifold end of the alternator.

Roger Parker

Thanks for the alternator location.

I have definitely not run out of fuel this time as I zeroed the clock and have only done 30 miles from approx 23 (couldn't get anymore in). I could only get a further 5 fuel in after doing the 30 miles. I don't think it's leaking as there are no visible signs/smell.
Prior to the car dying this time I managed to keep it going for several miles by changing through the gears (all I could think of and I managed to get within feet of my house!)

So it seems to be acombination of
1. can't get the fuel to go in at usual speed, and can't get the usual quantity in
2. fuel gauge is now unreliable (but only when experiencing loss of power)
3. loss of power - presumably as fuel not getting through
4. now won't start but turns over fine


B O'Mahony


The symptoms you describe, except for the problematic filling, could also be attributed to a loose connection on the ignition switch or a faulty switch. The black/yellow wire is the one I suspect. Disconnecting this wire intermittently will remove electrical power from ignition coils and gauges as well as other items like the wipers. If you can, try connecting a bulb to this wire and the other side of the bulb to an earth. If the bulb flickers or doesn't glow at all, when the power loss is happening, then there's your problem.

Huh! While typing this my alarm went off. My car is 75 yards away on the other side of the street and I'm upstairs in a bedroom. Picked up my keys, placed the blipper under my chin and turned off the alarm from where I'm sitting. Is this distance a record?


Bruce Caldwell

Thanks for all your responses - here is the end of the saga...

A friend called out the AA for me and guess what - the car started unaided! The AA man changed a few fuses, the next day it started fine but broke down again within minutes! So I gave in and requested the dealer to recover and fix it. The result is a 250 bill .... apparently there was a corroded connection to do with the fuel pump and the sender unit / fuel gauge (something like that). I still had nearly a full tank of petrol and had never run out in the first place! Well done to Rog who suggested this in a separte e-mail.

B O'Mahony

Why did Rog have to suggest this in an e-mail rather than on this bbs?

I would have thought to have it on the bbs archive would have been worthwhile even if it didn't fix your problem?

L Reid

Please don't blame Rog, I copied my 08.09.02 note above to Rog and asked him to respond by e-mail as I don't have access to the Internet on a daily basis.

B O'Mahony

This thread was discussed between 31/08/2002 and 14/09/2002

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