K-Series Cranking For Oil Pressure

[IanJ]

I am planning to perform an oil change on my 1.6 Superlight fitted with an Apollo and was looking for some further advice on the procedure I should follow for establishing some oil pressure before attempting to start the engine.

 

Disconnecting the inertia switch will prevent the fuel pump from supplying fuel to the cylinders and with the Apollo I am expecting to need to crank for around 40 seconds before seeing any pressure registered.

 

The question I have is whether it is better to take the plugs out (kinder on the battery/starter) or leave them in?

 

If the usual practice is to take them out, should I be concerned about damage to the ignition system (coil/ECU) if the spark plugs are not able to dissipate charge?

If the the usual practice is to leave them in, I assume that the loading on the bearings resulting from compression within the cylinders is negligible compared with the loading generated when the charge is ignited, hence the benefit. Is this understanding correct?

 

Thanks, Ian.

[Dave McCulloch]

My personal method only, but I usually take the plugs out as I check / regap them at the same time.

 

I also disconnect the crank sensor wiring which is on the offside of the engine at the rear - underneath the inlet plenum, at about 2 O'clock to the flywhell if viewed from the rear. In this way the ECU doesn't know the engine is turning and hence there are no sparks to worry about. Like you, I've always been under the impression that electronic ignition doesn't like operating "unloaded".

 

I crank the engine in bursts of about 15 seconds with about 15 seconds pause to avoid overheating the starter motor.

 

Dave

[Sheds Moderator]

The jury's out as to whether this is necessary since an idling engine is not under heavy load. I however subscribe to the view that it's a good idea to prime everything. I just pull the LT lead off the coil and crank away until the gauge starts moving. Sod the battery and starter, that's their job. Then reconnect the coil and vroom.

[IanJ]

Thanks for the input, guys - the crank sensor idea hadn't occurred to me.