Pre ignition problems

[milwain]

Hello im having some trouble with my xe everytime i turn the ignition off it trys to fire back up iv been told it could be pre ignition but dont understand what that means has any body ever has this befor and how can i solve it thanks matt

[Spudly]

Im going to guess its a dizzy one, and in which case it sounds like the timing is badly out on it and it needs the timing adjusting via the dizzy (if thats possible on an xe)

[Iain]

This is pre-ignition: http://en.wikipedia.org/wiki/Engine_knocking#Pre-ignition

I'd check the wiring on the ignition barrel/key area to make sure it's not continuing to get live/ignition live to allow the ECU to carry on fueling.

[milwain]

Its a coil pack engine and what would i have to check on the barrel im not the best with electronics

[Andy]

Its the clocks that make them carry on running

[Spudly]

FLOL, yeah that happened with mine actually, disconnect the plug on the back of your clocks then fire it up and see if it does the same when you turn it off!

[milwain]

Ok ill try that. Why would the clocks make it do that ????

[Jon_nova1]

something about the alternater charge indicater

[milwain]

Will it damage my engine if it keeps doing it because it sounds ruff when it happens

[Spudly]

Ok ill try that. Why would the clocks make it do that ????




Mine did it as the tracks on the flexible membrane on the back were damaged, theyre lain on one sheet of plastic, with another pressed on top, after a while the glue starts to come apart and if the clocks have been taken out/put back roughly then the tracks can come off and short together, when we had first got mine running i didnt have the clocks connected, i fitted them as the battery wont charge without them connected, and when i went to switch off the engine it just carried on running as there was a massive short on the clocks, i had to pull the ecu switched live to turn the engine off lol

It could be possible that you have a small short on yours and could be causing it to run on, it might not be this at all but its worth ruling out as a possibility!

[milwain]

Cheers spudly i have had the clocks out when i built it to wire the temp and engine mangement up so probably done the damage then.
So if i just unplug the back of the clocks the battery wont charge ?? Iv got some mk2 clocks do they fit into a mk1 ?

[Spudly]

The battery light needs to be connected on the clocks to complete the charging circuit, it wont kill your battery straight away having the clocks unplugged so you will easily be able to pull them out and unplug them to test this theory, the mk2 clocks have a bigger plug than the mk1 so they wont fit unfortunately.