1977 Mg bgt petrol tank problem?

1977 Mg bgt petrol tank problem?

Author
Discussion

Droob

Original Poster:

2 posts

115 months

Saturday 2nd August 2014
quotequote all
Hi, new to this forum which seems to be great! If anyone can help would be appreciated. Just bought my third gt and never had this problem before. Had about a quarter of a tank of petrol and all going fairly well apart from a bit of backfiring! Anyway going down a hill petrol gauge dropped to zero, warning light came on and I konked out. Once back on the level gauge went back up again and off I went. Any suggestions please?

mgtony

4,014 posts

189 months

Saturday 2nd August 2014
quotequote all
Are you sure you had about a quarter of a tank, or was that what the gauge was reading but might not mean it's correct?? Can only think it would happen if the tank was near empty.

nta16

7,898 posts

233 months

Saturday 2nd August 2014
quotequote all
as Tony's put plus perhaps crud in tank, fuel line or carbs

did your other two BGTs have a bit of back firing - that could be fuel but possibly more likely ignition problems, possibly needs setting up from tappets onwards

NBTBRV8

2,061 posts

207 months

Sunday 3rd August 2014
quotequote all
Droob said:
Hi, new to this forum which seems to be great! If anyone can help would be appreciated. Just bought my third gt and never had this problem before. Had about a quarter of a tank of petrol and all going fairly well apart from a bit of backfiring! Anyway going down a hill petrol gauge dropped to zero, warning light came on and I konked out. Once back on the level gauge went back up again and off I went. Any suggestions please?
The cheaper aftermarket fuel tanks don't have baffles, so all the fuel sloshes to the front and the pump cavitates air.

Droob

Original Poster:

2 posts

115 months

Sunday 3rd August 2014
quotequote all
Thanks for all ideas so far. I think the previous owner put a new tank in so aftermarket. Have woken to another problem this morning, petrol leaking out of fuel cap/filler hose (filled the tank after the "downhill" incident) - is this something to do with ventilation (non!). The filler cap doesn't seem to be a vented one, probably help to change it?

nta16

7,898 posts

233 months

Sunday 3rd August 2014
quotequote all
if the tank needs venting and isn't that could cause the car to cut out, easy way to tell is to remove the petrol cap when it does it and it it starts to run again you've probably got your answer

but I'd have thought if it has the wrong petrol cap it would have been noticed sooner unless it's like the typical MGB and rarely driven and more rarely any reasonable distance

petrol will 'expand' with heat which is why you shouldn't overfill your tank in summer as it will spill out of a vented cap and why you should try to fill your tank when it's cool to get more petrol for your money but remember to allow for 'expansion' when things warm up