quick Compression test question

[Nova_Tek]

Gonna attempt a compression test right after my dinner :D

Am I right in thinking that all leads to be removed from the spark plugs, unclip the connector socket that plugs into the coil i.e the pos and neg terminal plug, do each cylinder 1 at a time removing the spark plugs as you go along?

Crank the car for 5 secs or so with throttle open?

Just double checking so I do it properly.

Thanks :thumb:

[Adam]

Remove the ht lead from the coil, and the fuel pump relay if its an injection engine.

Remove all four spark plugs, hold throttle wide open, turn engine over on the starter.

[Nova_Tek]

its a 1.2 carb. already removed the supply hose to the carb. So its remove all 4 plugs and ht lead from coil to dizzy?

The compression guage manual states what I mentioned above.

Do I not remove the plug that connects to the coil? if that stays connected will that not supply the coil with power?

Just asking so I dont do nothing silly.

[meritlover]

just pull the connector off the coil (multi-plug) saves sparks going everywhere due to removed king lead.

[Adam]

Yes it will supply the coil with power, but it wont spark because the ht lead is disconnected.

Disconnected the supply hose BEFORE the pump i take it?

[Nova_Tek]

just pull the connector off the coil (multi-plug) saves sparks going everywhere due to removed king lead.

Thats what I thought.

[Nova_Tek]

Yes it will supply the coil with power, but it wont spark because the ht lead is disconnected.

Disconnected the supply hose BEFORE the pump i take it?

Yep supply hose to the pump

[meritlover]

dont worry about the fuel to the carb, even if you did disconnect it the bowl would be full anyway. for all the time its turning over, with the plugs out, itl just evaporate off anyway, and with no plugs in it wont be drawing all that much air in through the inlet anyway.

[Adam]

Thats what I thought. Disconnect that too then if you want.

Its fine with that left connected, as long as you dont do something daft liking shorting the coils ht terminal to the chassis or something lol

[Nova_Tek]

ok so recap

Remove coil multi plug and isolate and remove King HT lead.
Disconnect spark plugs from HT leads and Remove all 4 spark plugs.
Fuel pump supply removed
Screw tester into plug hole
Crank engine throttle wide open

[Nova_Tek]

Disconnect that too then if you want.

Its fine with that left connected, as long as you dont do something daft liking shorting the coils ht terminal to the chassis or something lol

Yeh hence why I have isolated and insulted it just incase ;)