Having spent 10 years with a TR4A, from rustbucket thru rebuild and showcar and back to rustbucket i think I am in a position to suggest some do’s & don’ts… Engine
4 cylinder TRs should start easily on the choke, the engine should run above 700 RPM without the need to “tickle” the throttle, partly because of its huge rotating mass. Once warmed up it should settle to a sub-1000 RPM idle and the sound from the tail pipes should be an even blub-blub-blub-blub. If it goes blub-blub-cough-blub or will not start easily, then its most likely a carburation fault (unbalanced or air leaks), or in a damp climate it may be an HT lead or distributor cap issue.
In any case it’s important that you get it started, put ether down the carb or heat the sparkplugs with a blowtorch – whatever it takes. once it’s running you can get a feel for the true condition of the engine. Oil pressure should be 50-60 PSI above 2000RPM and about 20PSI at idle, huge bearings mean low oil pressure doesnt hurt the bottom end of the engine. However the valve gear on this engine is short of lubrication, so running with low oil pressure will eventually chew through rocker shaft bearings.
Take the oil cap off and use a torch to peer into the valve cover (engine still running), you should be able to see a little bit of oil splashing about. Total dryness is a warning sign. Also check the amount of crankcase pressurisation as you remove the oil cap & try to feel the amount of gas coming out. The cap should not come off with a bang, and there should not be a blast of gas coming out (this can be difficult to tell as there is always some “drumming” of the air here). If you see problems then expect worn bores/rings, however this isnt a big deal on a TR given the wet-liner design (you can change pistons & bores).
Driving a TR should be easy; the clutch is heavy but the massive engine contributes to “unstallability”. You should be able to floor the throttle in direct top gear at any speed greater than 30mph and pull away smoothly. There should be no pre-ignition (pinking) and certainly no misfires. Pinking could indicate over-advanced ignition, low octane fuel, overheating or oil contamination due to the crank breather assembly not working. The cooling system is simple and should function, if not suspect a clogged radiator or silted-up engine block. It’s quite common to fit an electric fan to supplement the mechanical one, this certainly helps in modern traffic. Most importantly, there should be a fibre board cowl fitting between the front valance and the radiator; if it’s missing air will not be forced through the radiator. Water pumps last forever and generally fail gracefully.
On TR4As the exhaust manifold will crack if the bolts between the inlet manifold & it are missing. Use a torch to look at the areas where the manifold’s pipes join; there should be no white marks or obvious cracks. The cylinder head of the engine can crack as well, this can occur internally which is almost impossible to spot, but it can occur between a waterway and the outside. You can check for this by stopping the engine and checking for any water weeping from the “distributor side” of the cylinder head where the pushrod tubes are.