BMC 1300 hot starting woes

[Leyland Lawrence]

Sorry, boring thread for many but would appreciate any help

 

BMC 1300. A Series, low mileage used only for short journeys so this might have been a problem for years but the owner wasn't aware.

 

Starts perfectly from cold. But starts to die after 4 or 5 miles or ten minutes and won't restart. Not running lumpy, it just dies.

 

Following parts less than 1500 miles old:

New condenser

New non ballast coil receiving 12v

Newish points

new cap

New plug lead

Tried hot wiring coil straight to battery but no effect.

When car dies, still a spark albeit weaker (possibly)

 

No sucess. Still won't start. Fuel?

1. Look in engine bay once it has died. Fuel filter empty! Take off the fuel filler cap - just in case there is a tank vacuum
2. Connect a tube to the in-line filter outlet and crank the engine. Fuel comes out.

3. Spray fuel directly into carb, no effect (so I might have an ignition problem too)

4. Fuel pipe from fuel filter to carb not blocked or kinked.

 

Fuel pump quite hot though. Is that normal?

40 mins later restarts
 

Garage hasn't been able to sort but then I wonder how many younger mechanics have much involvement with antique technology like this.

 

Thanks for any ideas.

 

[RichardMoss]

I don't see "new rotor arm" on that list.  A well known problem these days and well worth trying a new one.

 

They have a habit of shorting out when warm and will only start working again after cooling down.

[DaveAspley]

Fuel vapourisation in the lines combined with a potential ignition fault? Does the fuel line run near the exhaust? Maybe a broken clip letting it dangle nearby. Would explain the hot pump.

[Sigmund Fraud]

Sounds more like an ignition problem to me. The best way to eliminate fuel evaporation would be to unscrew the float chamber top after the engine has died (it's not as if you'll have anything better to do while waiting for the thing to cool down !). If there's fuel in there, it's an ignition issue.

 

Experience has taught me to always change the float chamber gasket after the above operation. Otherwise petrol will seep out and end up dripping on the hot exhaust manifold !

 

Following parts less than 1500 miles old:

 

It's no secret that the quality of new ignition parts has become shockingly poor in recent years. Even branded parts can fail after a couple hundred miles ! So do make sure the 'new' bits are still working and, if in doubt, replace them with new old stock bits.

[warninglight]

Did you keep the old ignition bits? Worth swapping some of them back on, I'd start with the condensor as they can overheat and cause those symptoms!

 

I've been lucky with my 1100 but the Land Rover is waiting for its new Lucas ignition bits after cutting out like that on a greenlane, on my own. Took 20 mins to let the condensor cool down and it was fine again...

[jbz2079]

My 1500 Allegro started doing this after I serviced it.

I like you only found this out on the first long trip.

The difference was mine would still run but very badly, miss-firing and spitting and banging.

Then after 30 minutes it would re-start and run normally sometimes for the rest of the day.

 

The main problem was it always ran perfectly normal when I was at home and had some tools to try and look for

the fault.

 

I got lucky one day and it threw a strop just as I got back home with my mate in the car.

I whipped the king lead out the distributer and got him to crank the engine.

The spark was very weak and a very sickly looking yellow colour.

 

I changed the coil for a new one and thought I had cured it, but I hadn't, it had a strop the next day on a steep hill and did not have enough power to climb the hill.

 

After a 30 minute rest it drove home.

I changed the condenser for the one I removed and it never done it again.

 

A friend hade a Chevette (Shovit)  that used to behave very similarly, used to miss-fire and eventually stop at the same place every morning.

This turned out to be a pin hole in the radiator spraying coolant onto the distributer.

[Stixy]

Electric fuel pump ?    

[Junkman]

I think it's a fuel vapour problem only. The fuel pump should never get hot. Petrol starts to boil at 60C.

Is there a heat insulator block between the engine block and pump?

 

http://www.ebay.co.uk/itm/Petrol-Pump-Spacer-Gaskets-for-Austin-Morris-Mini-998-1300-Mk-3-1970-on-/390574788436

[derek9213]

are you running a fuel return back to the tank, if you are, blank it off or clamp it with vise grips and retry it, the float can stick after a while shutting off the fuel getting to the carb bowl and the fuel can be bypassing the carb and run straight back to the tank, but with it blanked off the fuel pressure from the pump forces the float jet to reopen 

[dollywobbler]

1500 miles can be a long time in ignition terms, though my experience of failing condensers on A-Series is a seriously bad misfire, especially with heavy throttle. You can often nurse them home with gentle throttle application. While 90% of fuel problems are actually ignition problems, I do also think this may be a 10%er.

[lisbon_road]

Modern petrol is much more volatile than the stuff when these cars were made.  Hence designs that were acceptable with pipes running close to sources of heat and so on may now not be.

 

Also very much like a coil failure, where they recover after sometime.  Would not be the first person to have swapped something and have to do it again. 

 

Good luck.

[PhilA]

+1 for crappy "new" ignition parts.

 

Condensers have always been Russian Roulette, but these days you seen to be playing with many more bullets loaded instead of just one.

 

I had a series of bad condensers (new in box) that either didn't work or caused the points to burn up in a couple hundred miles.

 

Phil