Many thanks, Alan, this is exactly what I needed! I already have two versions of the Haynes manual for the 240, both covering almost the same years, but with very different content, and neither of the two contained what you just posted! I saw three wires and wondered if it is a three-phase encoder or so, but it sounds like just a simple coil, the third wire perhaps being a screen or ground. I’ll check if the sender still works at all, for a start.
Update: I took it out for a drive last night. Started out great. The idling was good, the rpm still dropped a bit too much in gear but it seemed to handle it better. However, a few minutes into the drive, at around 30 mph, the engine suddenly started running a bit smoother and with more power. I took my foot off the accelerator and the rpm was stuck at 1800 or so! Then all of a sudden it dropped back to normal on its own. There is certainly an intermittent fault there. This happened twice.
I suspected a fault with the many vacuum hoses. Removing the A/C bypass hose with A/C off increases engine idle speed (as expected). Removing the distributor vacuum advance hose from the distributor end and NOT plugging it has no effect on idle speed. I don’t feel any vacuum at all there! I’d better dig out my vacuum gauge and some new hoses…
I am also suspecting something amiss with the ignition, so I grabbed the dwell angle meter, only to realise that it has given up the ghost (after decades of fruitful service at least)! I ordered another one. Points adjustment will have to wait a bit longer. I’m also waiting for new points and plugs to arrive, so I’m tempted to just replace the whole lot, along with plug leads and condenser, preventatively. At least then I’ll be sure this is all done properly. Also ordered a new carb diaphragm, just to have as a spare. I am still wondering what this black plastic bit is, on the manifold, where the A/C bypass valve hose connects.
Anyway, I drove back and put it on ramps.
A few bodges underneath… The transmission pan had obviously been taken off at some point and was replaced with no gasket, only a big mess of RTV silicone, perhaps Permatex Red or similar. So I definitely found the source of one of the new leaks!
I’ll order a new gasket to refit properly when I’m done with partial ATF drains. It is leaking a little bit from several places, including the torque converter grille, or the vent above that. I couldn’t find a plate on the transmission to identify which one it is. I did the first partial ATF change. I used Type F. What came out was better than expected, but certainly due for a change. The drain plug only has a flat-blade screwdriver slot…!
Is this normal?
Plug and seal:
As there is a drain plug there, I decided against using a pump. PAS drain/refill/bleed to follow.
Another slight oil leak comes from the steering gaiter. Another bodge:
It is not the correct type, being much too long, and fitted over the hose leaving a huge gap. Only seems to trickle a drop at full lock, which may simply be a matter of fitting the rubber gaiter correctly (not over the hose).
Perhaps relevant to the “sticky throttle” issue: I topped up the carb dashpot with ATF prior to that drive. It was already dark so I think I overdid it a bit. The plunger was taking a good while to sink back in. The level was perhaps half-way to the top. Any less than that and there is no resistance felt when refitting the plunger. Anyway, the next morning the oil level in the dashpot had dropped to the “no resistance” level. Perhaps sucked in? Or a fault in the diaphragm? Should there be any resistance felt when replacing (or removing) the plunger on these carbs? Exact level aside, how does the plunger feel in yours? Like there’s nothing in the dashpot or like it’s packed with honey?
Next on the to-do list: Coolant flush, another engine oil change, replace all belts, rear axle oil change, ignition system check/adjust, and after a few miles, go over everything again and check all adjustments.