What is the current rule of thumb for filling a M3W fuel tank. I've heard that if you allow the gas pump to automatically click off, you run the risk of a non starting or poor running engine. I have been trying to calculate how much to put in according to what my inaccurate gas gauge reads. Not exactly scientific. Any advice. LarryS

I fill it up full and then use VERY light throttle, building up confidence.

The trouble is that with a poor design of filler neck (to cause the pump to shut off just with its own flow rate), an inaccurate gauge and a few other factors, it is very difficult to know exactly how full the tank will be. I fill her up and go easy. With a bit of practice you can feel it start to miss without it cutting out.

Normally I fill to three cutoffs with 10 second gap between. Only caught out once with lazy cutoff and finding no more would go in after first click. Engine ran very rough and management light came on (as well reported) but sorted itself out after three gentle miles.

I fill very slowly until cutoff and then wait a few seconds and repeat twice. A couple of times it has run really rough for a couple of miles before clearing.

Last weekend I had a different experience but I guess related, I filled up and the car ran fine, parked it overnight front down a slight slope, in the morning there was a faint smell of petrol. It started OK but the engine management light stayed on and it had a mild misfire for 45 miles, on restarting the engine light went out but came straight back on another 2 miles drive and then after sitting for a couple of hours it started, engine light went out and the engine ran fine.

+1 for the 3 clicks method.

I also try to make sure I do at least 10 miles after filling up before parking for any length of time to avoid any chance of the misfire/cut-out problem.

If you do overfill then releasing the filler cap for a few minutes (stationary!) is supposed to help.

I fill slowly because it allows the fuel to run from one tank to the other evenly. I make sure the nozzle is in as deeply as it will go. When it clicks off, I'm finished. I have the longer tank float and read 160-180 miles before the gauge reads zero.

Ditto on this. Every time that I would attempt to squeeze just a little more (3 click method) it would take at least 12-15 miles of running to clear up the misfire.

This way clears that risk, as well as the smell of fuel. This thing really does not like a full stomach. It burps...

The key is to make sure the nozzle is all the way in and then fill till the clicks stop allowing plenty of time for the tanks to equalise. This is OK till you fill up in BP Ambleside where the clicker doesn't work properly and end up with a litre of petrol all over the rear end and the forecourt! The lady at the till thought it all hilarious and had no intention of reporting the incident so that repairs could be carried out.
My motto being" if they invented petrol tomorrow it would be illegal"! This resulted in a very full tank and I suffered a couple of missed beats in the first Km. or two but nothing more.

Ah now I know what I did the other week after filling up I had a misfire for a few miles. I was in a rush filling up and did try to get every ml in. Won't do that again.

1. Fill slowly to the brim, I don't use the locking stopper.

2. Leave the ali. cap open whilst I go and pay, this allows any air to vent and the fuel to settle.

3. Close cap and drive off as normal.

If I miss out step 2 it coughs and farts and the engine light comes on for a mile or 2.