15 replies to this topic

[Chrome_GT]

Hi, My mini is getting some attention again after 4 years! Anyway here's my current problem #1.

The car doesn't seem to have fuel available when starting. It takes 20 seconds or more of good cranking before I get it to fire up. Once running it is fine. The other way to start it is turn it over using CRC Jumpstart into the carb. I think the two starting methods are achieving the same thing. They are spinning over the engine and priming the fuel lines. If i restart within hours then it starts fine. If I restart the next day then I have to go through this exercise of draining the battery or quirting jump-start into the carb. I suspect that my fuel is draining away from the carb if i don't run it regularly but am not sure.

 

I'm sure I'm not the first to have this problem but have failted to find anything similar in the forum search function.. Where should I start looking? 

 

(Problem #2. Perhaps related, I find that in the first couple minutes of driving, i can't depress the accelerator too quickly or it goes all asthmatic and wants to cut out. If i press the accelerator gradually the revs keep up and the car doesn't want to cut out. This comes right once the car has done a few trips around the block. Not necesarily a cold/hot thing as I only tend to drive the car after it's been sitting idling after a good 5-10 mins) 

 

Mini 1971.

Was 1000 but now 1310cc from a Morris 1300 with Factory Carb, standard air filter. I think I used my original 1000 mechanical fuel pump (I hope that isn't my problem).

 

thanks, 

Ray

[Carlos W]

Is the choke operating correctly, and I'm sorry if this sounds rude, but do you know how to use it?

[grumpy dad]

Hi

its sounds like you are right 

as the car has been standing for 4 years 

there is bound to be muck in the tank

 

in the fuel pump there are 2 flap valves 

sounds like there is muck it them 

and thay are being held slightly open

thay are in the pump body

so you will have to take the pump of

put a in line fuel filter before the pump 

 

2 quick fix for you 

 

keep the tank full my guess is the top of the tank 

and the carb are almost the same hight 

so the pump will not have as far to lift

 

fit a SU electric pump in the boot 

[Chrome_GT]

Yeah chock seems to operate fine. Cable adjusted and operating the linkage as expected and idle goes up etc. I have issues starting the car regardless of whether the choke is in or not. Seems to make no difference there.

Flap valve sounds interesting, and fitting, so I'll definitely look into this further. This problem has been around pretty much the majority of the time since I took it off the road. I owe my cars some TLC.

[Chrome_GT]

I'll try the fuel level suggestion too, will fill it up before the next startup and see if it starts earlier

[grumpy dad]

I'll try the fuel level suggestion too, will fill it up before the next startup and see if it starts earlier

Hi

the first time you start up it will probley make no difference 

but it should after that

[Shaley]

will watch this one too as having exactly the same issue..!

Was wondering if some sort of non return type valve could be introduced to stop the fuel dropping back?

[Dusky]

They sell additives to clean jets etc.
Maybe this could clean the fuel pump?

[Chrome_GT]

Undid the hose from the pump to carb and tere was still fuel there after 12 hours since last running. So it must be a very slow leak back through the pumps inlet outlet valve(mentioned in te Haynes manual)

Haven't got the pump off yet. Quite an awkward positon!!!

The idea to put a check valve in line is quite a good one. Very easy to do, and cheap on eBay but it's hard to know what is good enough.

Does anyone know the pump displacement, flow per rev, for the pump? Maybe I should check the Haynes for this info.

I'll keep you posted

[Chrome_GT]

How does the float bowl fit into this scenario. If the pump is allowing fuel to drain back through, does this drain fuel from the float bowl aswell? Or does the float bowl reserve a certain amount of fuel no matter what is happening in the supply line?

[cal844]

Change the fuel pump... The 1000cc pump wont have enough fuel psi

[grumpy dad]

Hi 

if you put a check valve in 

it must be before the pump

[Stiggytoo]

The float bowl should retain the fuel it has (depending on which carb you have).

[Chrome_GT]

Ok maybe i need to check the float bowl. The whole reason we were suspecting the pump is because i cannot start the car without spinning the engine over many times. It comes to life after 20 seconds or of cranking (unless I'm restarting within hours of the last time it ran). If the bowl has fuel then surely it should start straight away? I'll look inside the bowl before doing more with the pump.

 

It's the std SU for a Morris 1300 SU HS4. It's a single.

[Chrome_GT]

The Float Bowl had plenty of fuel in it when i had a look tonight. I'll have a look in the morning. Since the Carburettor takes fuel from the bottom of the float bowl, and the inlet pipe to the bowl is at the top, I can't see how the fuel pump is the cause any more. But still keen to hear any thoughts.