Getting Gwen the Mini to Run.

DanClarke said:

Whole bodyshell is like new after the rebuild.
View attachment 336518
I have an MOT scheduled for tomorrow.
Interestingly, I took it out today and in the first part of my journey I had to turn left and then up a steep hill, it lacked power and we got the pre-detonation in the inlet side. I pulled the choke out and we regained power and stormed up the hill.
This led me to think it was under-fuelling. So I have tweaked the jet down a smidge and will try the same trick tomorrow.

One other mystery is what the valve clearances should really be. One school of thought says ALL A+ engines 12 in/12 Out but the Vizard-Wizard book has a table saying the Metro engine with std rockers should be 15 in and 15 out.
Now as I cannot identify what engine this is for certain, what should I do?
Try 15/15 and if it is a clattery bucket of bolts put it back to 12/12?

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To look at your post backwards, yes, try the 15 thou gaps and if it remains clattery when hot then you can tighten them up one thou at a time until it stops. A tappy tappet is a happy tappet, as they say! It is a MG metro engine after all. You could also use compression test to see what changes come about as you do it. You want peak compression to be sure the valves are opening and closing properly.

I am now wondering if you haven't got a little bit too much advance coming from the vacuum. When driving uphill with your foot flat on the gas, it'll advance like that, which is what you were doing. BUT do make sure you do the tappets first. If your tappets are a bit tight then the inlet valves could be open too long which could mean that is why you are getting the pre-detonation.

If that doesn't stop it, try just disconnecting the vacuum tube and seeing how it goes without it. I doubt it'll continue to pink, if pinking is what it is doing.

I don't think continuing to richen it is the answer. You could do plug cuts to check how rich the mixture is.
But you have got enough to be going on with. You are very close to having it right.

How'd the MOT go?

Firebobby1 said:

How'd the MOT go?

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Passed.

Hmmmm.... petrol pump was weeping fuel.
Not the best thing to have dripping in the vicinity of a hot exhaust pipe is it? A shiny new pump arrived yesterday but "curses" the input-output pipes are fixed in their positions such that the output points straight at the exhaust. The old SU original has input/output on the same face of the top half of the pump and they are pointed away from the exhaust and towards the left wall of the engine bay.
Q: Did the diaphragm fail due to age or has the use of E5/E10 petrol caused it to go brittle? It is a 3-layer rubberised cloth sandwich. I reckon E5/10 has been the last straw for a tired diaphragm.

So there was a frantic search online to find a replacement diaphragm (having been told "Not Available" any more) and bingo, I found one. EX MOD stock.
Old pump now in bits awaiting the new diaphragm. Hopefully it will mean all the old piping and connections can just go back as they were after I have put it all back together.

Next: Why doesn't it ever come off the cold-stop on the temp gauge? Tried 2 different senders (tested as OK in boiling water) but still no joy. I wonder if someone has failed to put a thermostat in and the engine never gets properly hot because of the oversized radiator?

Fun this Mini business isn't it?

DanClarke said:

Hmmmm.... petrol pump was weeping fuel.
Not the best thing to have dripping in the vicinity of a hot exhaust pipe is it? A shiny new pump arrived yesterday but "curses" the input-output pipes are fixed in their positions such that the output points straight at the exhaust. The old SU original has input/output on the same face of the top half of the pump and they are pointed away from the exhaust and towards the left wall of the engine bay.
Q: Did the diaphragm fail due to age or has the use of E5/E10 petrol caused it to go brittle? It is a 3-layer rubberised cloth sandwich. I reckon E5/10 has been the last straw for a tired diaphragm.

So there was a frantic search online to find a replacement diaphragm (having been told "Not Available" any more) and bingo, I found one.

EX MOD stock.
Old pump now in bits awaiting the new diaphragm. Hopefully it will mean all the old piping and connections can just go back as they were after I have put it all back together.

Next: Why doesn't it ever come off the cold-stop on the temp gauge? Tried 2 different senders (tested as OK in boiling water) but still no joy. I wonder if someone has failed to put a thermostat in and the engine never gets properly hot because of the oversized radiator?

Fun this Mini business isn't it?

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So you have finally found the source of the pong of petrol!
Well done!


It appears there are a few pumps that could do the job and Metro turbo ones are electric and sit in the boot, prolly, or nearby. (Our old 850 woodie had an electric one. It broke down first in Spain then again in France. So we got an extra 3 days holiday on the AA 5 star.)

Have you not got an MG Metro Haynes? I found mine useful. Sadly now with grandson.

I don't see how the diaphragm has failed as it seems to be powering your engine just fine! Modern petrol will deffo have done the old pump no good at all. The NOS one will last for a while. Better still would be one made for modern petrol, if you can find one. A generic electric one would perhaps be better on that level.

Easier and quicker to check that the gauge is actually working than having to drain the coolant out to remove the stat. The stat housing can be a right bitch to get off, I had to saw mine off! But feeling around inside the housing with a finger or a bit of wire will tell you if there is a stat there or not. Wax stats are more likely to fail shut, or nearly, than open. Driving around on a cold engine isn't at all clever as clearances cannot close up, how do the rad hoses feel? Does the heater work? Yet again driving on a cold engine will distort the tune. All told I get the feeling that it is more likely to be the gauge or a connection to it.

Leaving the stat out isn't clever for another reason, the coolant will not flow as you would think. It would do, more or less, if you butcher the stat to remove the middle piece, but even then.

If you can get at the gauges easily then the fuel gauge is the same as temp so connect temp wire to fuel gauge see if it works. If it runs cold then either thermostat or gauge

Stanleysteamer said:

I don't see how the diaphragm has failed as it seems to be powering your engine just fine! Modern petrol will deffo have done the old pump no good at all. The NOS one will last for a while. Better still would be one made for modern petrol, if you can find one. A generic electric one would perhaps be better on that level.

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Well, I can't be sure but the ABD1001 pump has a vent hole in the lower half so that on the down/pull stroke of the diaphragm the air pressure created on that side of the diaphragm has somewhere to go while the fuel is pulled in the top side.
Fuel was to be seen dripping out of this non-fuel-side vent hole. So the 3-layer jobby must have been letting by.
I guess the pump was still able to keep the carb bowl topped up even though it was leaking a bit.
I will add a fuel stabiliser/conditioner (Castrol Valvemaster) to the E5 on every fill-up from now on.

When this diaphragm goes I can swap to a new style modern-fuel pump and redo all the fuel delivery pipework I guess.