Engine problem.

[airsniper]

Firstly may I say hello.

Secondly while I have been reading this and other M.M. forums a technical problem that is baffling me has made me decide to join.
I recently (10 months ago) bought a 1954 Moggie that has been re-engined (1098cc). As Ive owned several Minis in the past Im no stranger to the BMC 'A' series engine and have done a fair bit of work on them. This one though has me baffled.

The symptoms. It starts, on choke, and runs great for the first 20-30 minutes reducing the choke accordingly when the engine warms up during the first 5 mins as per normal. Acceleration is what I would expect and she (Gloria) runs well. After 20-30 mins it will just stop. No splutting. No noises. It ticks over fine. After 10-15 minutes it will start again no problems for the next few minutes then it will do the same again. Its getting worse and the time span is reducing. Its running on un-leaded petrol with petrol additive.

What Ive changed for new. The pointless ignition system. Ignition coil. Dizzy cap and all H.T. leads. Rotor arm.Spark plugs. Both fuses. Battery (the old one was showing its age anyway). Fuel pump. Ive by-passed the loom (white/black wire) and took a wire direct from the live side of the fuse box (fuel pump take off side) direct to the coil. Ive checked the polarity of the coil and its O.K. (The pointless system wouldn't work if it was wrong)

What Ive checked. The engine oil is fresh (under 1,000 miles). There is no water leak. There is no oil in the water. The engine turns over quickly (now the new battery is fitted). There is no noises or steam before it cuts out.
Ive checked the float bowl and its 1/2 full of petrol. There is no rust in the bottom of the fuel bowl. The fuel pump does NOT click after Ive waited 10-15 mins (so not fuel starvation?) . There is a good spark. The plugs are dry with a coffee coloured nose/tip. There is a good spark from the H.T. lead from the coil AND at the plug itself. Ive strobed the timing.

Like I say - its got me baffled. Any tips or info on this problem will be very gratefully received. Thank you.

ATB
Ian

[chesney]

Poor connection at the switch or fusebox maybe, something like that? Next time it conks out, maybe try carrying a multimeter to test?
Maybe poor connection to the pump, try removing fuel line and seeing if the pump clicks when it is removed.
Could be some silt inside the carburettor preventing fuel flow?

[les]

You could try another rubber hose from the steel pipe to carb, just in case the rubber inside is collapsing now and then. Fuel cap venting ok?

[airsniper]

Thanks chaps for the prompt reply and something else to work on.

Ive got a spade terminal set up on the battery terminal and the next time it happens I will take a live feed directly off the batt and by pass the ignition system/switch.

The 'rubber hose to carb' feed is a good one. I remember a reinforced plastic pipe collapsing on an oil feed on a Triumph T120 I once had. I though it was the big ends on the way out. Luckily I spotted it before I stripped the engine.

The fuel cap is a locking type - I thought that wouldn't be so air tight (but I will check)

The problem is Gloria picks the worse places to cut out and once youve got into a safe place and your tools out she runs again. Ive had her running on 3 cylinders when I was doing a plug check! Now I carry a spare plug in my pocket for testing.

[les]

Intermittent faults-----the worst type. Good luck.

[airsniper]

Intermittent faults-----the worst type. Good luck.

Tell me about it. Im driving round with listening to the engine and hoping summat will break or fall off then I will know whats wrong.

Once again many thanks for the replies so far and any future ideas posted.

I will, of course, keep you updated with events for future reference.

ATB
Ian

[panky]

If you've got a fuel filter fitted in the engine bay then get rid of it. They can be a source of fuel vaporisation and caused very similar problem on my car - dumped the filter and bye bye problem . Also check the mesh on the inlet side of the pump for debris.

[bmcecosse]

Sounds like fuel starvation due to non breathing cap - as already mentioned. When it stops, is the pump hammering away? Otherwise - fit a points dizzy and try with that.

[airsniper]

The fuel pump is new but I will still check the filter again.

There is no additional inline filter under the bonnet.

I may return to points/condenser so I can eliminate the new pointless ignition system.

When it stops the fuel pump is quiet. If I remove some of the fuel out of the float bowl the pump clicks a few times when I turn the ignition on (topping up?). If I turn the ignition on with the fuel line from the pump disconnected it spurts out. Delivery rate? ? I dont know but thats another thing I will have to test. When it has stopped and Ive checked the float bowl is half full +.
When I come to the car after its been stood for a few days the fuel pump clicks for a few seconds after I have turned the ignition on. I think thats normal and allows for petrol evaporating while the cars been standing idle. It then starts first time on suitable choke. There is no petrol leaks.

[kennatt]

Have you still got the old coil,I see you have fitted a new one, there have been problems with the aftermarket coils,stick the old one back on,or was the fault there with the old one. because the fault is classic with an overheating coil, ( here comes roy, but sometimes it IS the coil) Had several over the years do the same,well a couple anyway

[bmcecosse]

I missed the new coil... Yes, get back into to the old coil, many new coils are wrongly specified and/or poor quality......

[mike.perry]

Check the fuel filler cap, if it is not vented it will build up a vacuum in the fuel tank. When the engine stops remove the cap and then try starting the engine. The engine will stall quicker with a full tank than an almost empty one

[airsniper]

Have you still got the old coil,I see you have fitted a new one, there have been problems with the aftermarket coils,stick the old one back on,or was the fault there with the old one. because the fault is classic with an overheating coil, ( here comes roy, but sometimes it IS the coil) Had several over the years do the same,well a couple anyway

Ive binned the original coil as it was completely US. It had leaked most of its oil. I am working on Gloria this weekend so will borrow another known good coil.

(Sod it - Ive treat myself for Valentines Day and bought myself a another NEW replacement coil from a reputable Morris Minor spares specialist to replace the one I got from my local car accessory place.)

[northyorkspaul]

I had a similar problem turned out to be the points in the pump sticking now and then...cleaned them up and faintest bit or vasaline on and its run for 2 years...

[GBond]

Had a similar problem in a Triumph, could also be some junk in the fuel line from the tank restricting the flow to the pump.

[airsniper]

I had a similar problem turned out to be the points in the pump sticking now and then...cleaned them up and faintest bit or vasaline on and its run for 2 years...

Its a new pump. I got fed up of cleaning the old pumps points - maybe it wasn't the pump faulty after all.

[airsniper]

Had a similar problem in a Triumph, could also be some junk in the fuel line from the tank restricting the flow to the pump.

When she cuts I whip the float bowl cover off and its over half full of petrol. The pump doesn't 'click' before it starts to run normal again.

THANK YOU all for all the hints and tips. I was stumped and getting ready to start ripping my hair out. Your ideas and thoughts have given me some other avenues to work on.

[katy]

I am working on Gloria this weekend so will borrow another known good coil.

Sounds like a good plan.

[SteveClem]

Good old coils seem to be the best coils! So much of the new stuff seems to be rubbish. Is there a factory in China dedicated to producing complete crap?.

[pskipper]

I had a similar problem a few years ago, turned out that the jet head on the carb was ever so slightly misaligned, not a problem when cold but once it warmed up the carb stuck solid and the car would cut out. When it cooled down again it started and ran fine. Took me ages to work it out!