Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Revs not going to idle

For more precision the voltage of the throttle angle sensor for the 54 mm minimum 0.2 volts and I currently have with the 58 mm 0.4 volts at slow speed with Protune.

Sorry for my ignorance, but what do 54mm and 58mm refer to?

54 mm/58 mm is the diameter of the throttle housing, the volt measurement is made with the ignition on without having the engine running.

You shouldn't really try adjusting the TPS without Protune - its so delicate in its setting - go a micro millimeter too far and it will not run correctly. As Callum states with a voltmeter it can be done but easier with Protune. Also make sure engine up to temperature when you adjust it...finger burning time as the little screws are so difficult to get to.

And if you have a later TPS its non adjustable - unless you remove TPS and carefully elongate the fixed position holes to allow it to turn.

The correct sensor model is the PF4C, it is adjustable.

I’m following this with interest. I’ve observed similar behavior occasionally on my M3W, I coast to a stop in neutral and the engine is idling at about 2000 rpm, but as soon as the wheels stop turning it drops to normal. This behavior is intermittent, and I have wondered about it, but not tried to solve it yet.

The TPS supplied by S&S as a spare and also with a new throttle body is not adjustable unless you can get hold of older stock.
Have seen these non adjustable types fitted to later cars and also on a new crated engine.

it would be good to read the reference engraved on it to see what it also adapts to, it also costs nothing to do an adatative MAP reset also with protune so that the ECU recalibrates again.

Those are exactly my symptoms. I have an updatable ECU so will have a look at Protune later, I need to experiment though as I suspect it only happens when the engine is cold.