6 replies to this topic

[Vinay-RS]

Hi all, 

 

This morning as I was leaving home the Mini cut out. It then briefly started up again before cutting out again. 

Some backstory, a couple of months ago I fitted a set of rebuilt twin HS2 carbs to replace the existing single HS4 carb. Soon after I was having some issues with the car misfiring and cutting out. After some investigation, it turned out the distributor cap was worn and I figured this was the source of that fault. I replaced the plugs, leads, cap and rotor and the problem seemed to be gone. 

 

Fast forward to this morning, after the car cut out, I chatted to my friend who knows Minis better than me and we started ticking things off that might be the problem. Forst I just turned the key to check if the issue was a low charge or flat battery. It was swinging fine, suggesting the battery was fine. Next, I checked the plugs to see if I'd flooded the motor and they seemed fine. They weren't soaked in fuel and the plug colour was good too. I then checked the cap and rotor to see if one of them was broken and thus the plugs were not getting current. They were fine too. Next, I checked the float bowls and these were empty suggesting the engine was being starved for fuel. Figuring the issue must be an old filter at the back, I checked under the rear subframe, and surprisingly, there was no filter which is obviously terrible.

 

The car has a mechanical fuel pump, and I was wondering if that could have failed because I've been using the car without a filter? I'd need to source a replacement and I might be able to get one (condition unknown) from the same friend I was chatting to on the phone. I was wondering if there are any other things I could check before jumping at replacing the pump? 

 

Thanks, 

 

Vinay

[unburntfuelinthemorning]

There isn't normally a filter unless someone's fitted one.

 

Disconnect the fuel line to the carbs, crank the engine over.  If fuel shoots out of the fuel pipe then the fuel pump is alright.  If not then it's either the pump that's faulty, or the fuel line is blocked, or there's no petrol.

[Vinay-RS]

There isn't normally a filter unless someone's fitted one.

 

Disconnect the fuel line to the carbs, crank the engine over.  If fuel shoots out of the fuel pipe then the fuel pump is alright.  If not then it's either the pump that's faulty, or the fuel line is blocked, or there's no petrol.

That's a good check. Thanks. There is definitely fuel in the tank I checked with a stick. 

[Vinay-RS]

Follow up, how easy/difficult is it to remove the mechanical fuel pump with the engine in the car? 

[Ethel]

It's doable, harder if you have a performance manifold. Undo the engine steady to make a bit more room & pack the space below the pump with an old towel or similar to stop dropped bits  getting lost or wedged between the subframe.

 

There is a filter of sorts inside the tank, so it could be worth blowing/ sucking down the pipe to the tank before condemning  the pump. Also leave the filler cap off to be sure the tank lets air in to replace the petrol being pumped out.

[Vinay-RS]

Thanks! I need to source a new pump and gasket and I'm hoping someone locally has stock of a new one or that the one from my friend works. 

[Vinay-RS]

Thanks for all the advice. Took off the pipe to the carbs and got a friend to crank the engine with the pipe in a bucket. Fuel squirted out, so the pump was working. Checked the solid and flexible pipes to the carbs they were clear too. So, next I took apart the float bowl lids and it turned out the needle valve things were stuck in the closed position. Looks like some sediment had collected on them and they wouldn't move freely. Gave them a clean and the car started right up. Next I'll change the flexible fuel lines in the engine bay and fit a filter under the rear subframe just to be safe.