Sorting out the Lightweight

There haven’t been any updates for a while, but that’s because I have been too busy, not because of a lack of work.

The Lightweight is being a pig.  The engine is running very badly, misfiring, backfiring and stalling without the choke and running gutlessly with it.  Cleaning out the entire fuel system and rebuilding the carburettor (and later replacing it with a brand new one) had no effect, and replacing the spark plugs, coil and condenser have also had no effect.

I have rebuilt the distributor, which seems to have cured some odd voltage readings I was getting in there and un-seized the flyweight advance system, but to no avail.  I now have a very clean, pretty looking engine that still won’t run.  It’s not the points, timing or tappets – they were all cleaned and adjusted early on in the fault-finding process.

In the mean time, I have also done several other jobs on it.  I have refurbished the dash, including replacing the broken speedo (the mechanism in the speedo head was also jammed, not just the cable connector broken) with an MPH calibrated unit for 6.50 tyres (stripped and cleaned), replaced the broken oil temperature gauge while stripping and cleaning the three-in-one gauge, replaced the broken dash light switch and fixed the non-functional fog light warning lamp, fitted a voltage dropper so that the power terminals now produce 12V to enable phone charging and got the IR headlight switch working correctly.  The dash panels and gauge bezels were all stripped back to clean metal, etch primed and resprayed .  The radiator panel’s missing canvass strip has been replaced, as have the broken windscreen washer jets and hoses.

The broken clutch slave cylinder bolt was eventually removed, enabling the new cylinder to be properly secured, but the second gear still crunches on the change-down.  Tightening the main shaft’s rear nut and replacing the clutch cylinder didn’t sort it out after all, but at least the gear ganges are easier and more positive with no jumping since replacing the detent spring and adjusting the reverse inhibit lap and stick pivot’s grub screw.   It’s annoying, but I can live with it – we may have to double de-clutch, but it’s not going to harm anything.

I’m at a loss over the engine.  Mechanically, it is very good.  Something external is causing this, though I can’t seem to find any faults in the fuel or ignition system now.  I may have to resort to replacing the ignition system with a new replacement standard type in place of the original screened system as all of the components in this one are hard to source and incredibly expensive, but apart from the possibility of bad HT leads or excessive gaps between the distributor rotor and cap points fter cleaning them up, everything has been proven serviceable.  There is a slim chance it may be an air leak, but with new gaskets between the manifolds themselves and between them and the head, carburettor and carb base block, the only remaining source of a leak that could do this is the breather system – it has a funnel shaped device behind the carb which feeds gasses from the rocker cover cap to the carb base block below the choke tube, so if that breather system is not sealed, air could enter, bypassing the carb and giving a weak mixture.  I’ll try blanking that inlet port off, but I’m clutching at straws now.

What makes this even more frustrating is that I want to get this car up and running so that I can work on the others (one at a time) without being dependant on them and having time pressure to get the others back on the road.  It looks like I’ll just have to get on with the Range Rover’s brakes regardless and do one corner at a time to keep it generally available.