42 replies to this topic

[Philfy]

Ive blocked off the fuel line at the pump, im hoping when I check the tank breather it is blocked, that would explain a lot.

if not, im not sure what to do. gonna have to wait till the w/end.

just for reference, no cat, so no probs there, ill be waiting for the pop though.

[Stu1961]

Hi I'm not a mechanic but wouldn't it be simple just to disconnect the feed from the pump to the carb and turn the engine over to check the delivery. And how can a fuel tank pressurise to the point where it is flowing fuel surely if the breather was blocked it would create a vacuum which would stop fuel flowing completely. Fuel pump diaphragm seems totally logical engine isn't running because the fuel is going into the block and not up to the carb. Do hope I haven't spoken out of turn if I have I do apologise in advance.

[Carlos W]

If the fuel breather has become blocked the tank will pressurise due to evaporation of fuel whilst the vehicle is standing and due to these high temperatures!

[Philfy]

its all back together and now running,

Ive disconnected the breather, the pipe is pretty hard to blow down, so i dont think that helped.

in conclusion, I think it may have been a combination of things,

1, full tank of fuel

2, hot weather (standing all weekend in the sun)

3, possible blocked breather.

4, parked on a slight downhill slope.

i understand the comment about a vacuum, but also the pressure because of the heat.

its a strange one alright, never had it happen before, and its been a great car for over a year.

im leaving it tomorrow to see if it does it again and test it over the weekend.

 

never again park it down hill (wife will have to learn to reverse )

thanks to all who commented.

[Carlos W]

Well done mate, hopefully there wont be any long term damage!

 

You'll need to replace the breather pipe or your car will smell of fuel!

 

I don't know if you need to consider doing something with the carb, hopefully one of the gurus can comment on that!

[Captain Mainwaring]

its all back together and now running,

Ive disconnected the breather, the pipe is pretty hard to blow down, so i dont think that helped.

in conclusion, I think it may have been a combination of things,

1, full tank of fuel

2, hot weather (standing all weekend in the sun)

3, possible blocked breather.

4, parked on a slight downhill slope.

i understand the comment about a vacuum, but also the pressure because of the heat.

its a strange one alright, never had it happen before, and its been a great car for over a year.

im leaving it tomorrow to see if it does it again and test it over the weekend.

 

never again park it down hill (wife will have to learn to reverse )

thanks to all who commented.

 

 

Be aware, you haven't cured the problem yet, only one of the causes.

[Philfy]

 

its all back together and now running,

Ive disconnected the breather, the pipe is pretty hard to blow down, so i dont think that helped.

in conclusion, I think it may have been a combination of things,

1, full tank of fuel

2, hot weather (standing all weekend in the sun)

3, possible blocked breather.

4, parked on a slight downhill slope.

i understand the comment about a vacuum, but also the pressure because of the heat.

its a strange one alright, never had it happen before, and its been a great car for over a year.

im leaving it tomorrow to see if it does it again and test it over the weekend.

 

never again park it down hill (wife will have to learn to reverse )

thanks to all who commented.

 

 

Be aware, you haven't cured the problem yet, only one of the causes.

 

Well unless anyone has any more ideas...

If the tank has become pressurised, and this caused the fuel problem, once the breather is replaced, is there anything else to fix?

[sledgehammer]

In my opinion ... (with vent clear)

 

you just need the carb float valve to be checked / cleaned (if it is at fault)

 

when carb is off engine , & if left lying around , the float needle drops down (as no fuel in carb)

 

sometimes the valve surface can corrode a bit , and stop a good seal - (sealing surface is tiny)

 

I usually spin valve in its seat to bed it in a bit if it leaks

 

some valves are rubber sealed so would need replacing

 

I'm assuming the fuel pump is ok ?

 

& change oil & filter

 

I would also put a little bit of oil down the bores , so the rings arn't dry on start up -

 

wind the engine over with plugs out to bed the oil in

Edited by sledgehammer, 26 July 2013 - 04:59 PM.

[Philfy]

I put some old oil in (not used just had lying around a while) temporarily and just drained out to help flush out the crap.

new oil ready to go in.

vent pipe is off until i can sort it.

 

I agree the carb needs a look, i would have expected the valve to slow the rate the fule was syphoning through, maybe not???

good point about oil filter, i forgot that one, although a bit of petrol shouldnt hurt it?

 

already did the oil down the plug holes, but thanks for mentioning it.

[Philfy]

I have been doing some more checks and i think i may have found a problem.

the pipe on the top LH side of the carb (HIF38) which i believe is the overflow pipe,

this runs all the way to the top of the fuel tank, (where there always used to be just a pipe from the tank) via a valve or somthing.

with the carb pison removed, if i blow down the pipe on the carb, fuel flies out the jet.

therefore... if there was some pressure in the tank that goes to this pipe on the carb this could have been the problem all along???

 

can anyone explain the purpose of this pipe arrangment?

could the valve on the top of the tank be faulty, and should only allow fuel back the other way, i.e from carb to top of tank?

if the tank can vent along the pipe it would be like me blowing in, and fuel shooting out the jet.

 

im very confused

[sledgehammer]

overflow pipe don't normally return to tank - (except on injection - but is a proper fuel return pipe)

 

it normally runs down the side of  the clutch housing - in a metal pipe - too atmosphere

 

[I can understand the thinking - if the float valve is leaking - petrol will flow from the mentioned pipe - get it back to tank

 

find spare pipe on tank (the vent) -- connect to vent pipe on tank]

 

how many fuel pipes do you have running front to back ??

 

has one been added ?

 

take a pic of the valve

 

wonder  if someone has fitted a spi / mpi tank ? to  carb  car

 

take pic of carb & tank

 

http://www.minifinit...hp?f=22&t=67319

 

appologies to minifinity for the link

Edited by sledgehammer, 27 July 2013 - 02:09 PM.

[Philfy]

i cant figure out how to attach an image, so ill just explain.

the valve connected to the small pipe on the top of the tank appears to shut off when upside down.

i took it off, it has "top" written on it and blew through it, it shuts off when upside down.

it runs all the way to the front of the car (yes theres 2 pips running side by side under the car)

 

maybe it was my mistake thinking it went to the carb, now im not sure...

both this pipe and the pipe on the overflow on the carb dissapear under the nearside wheel arch into a drum thing.

ive given up for today, so now i need to figure out what the thing uner the wheel arch is doing?

any ideas??

for reference, its a 93, last of the carb mini's, it used to have a cat, but didnt need it for MOT, just scraped through on date.

 

on a positive note, mini is up and running now, all flushed out and new oil.

half a tank of fuel, and parked with the front uphill

[Alex_B]

I think your car must have been a SPI or something now converted as that sounds suspiciously like the injection set up and the drum under the wheel arch is a charcoal canister