Astra will not start

[adamwg]

I've just replaced the head gasket on my astra.

I cannot get it to start. All the timing marks are lined up and I'm shure there is petrol there i can smell it.

There is no spark at the plugs. I think there could be a problem with the coil pack. Does any one know how to test it?

There are 4 wires connected to the coil pack. 1 is ground, 1 is 12+ when the ignition is on. the other 2 read a fraction of a volt when the engine is turned over (these last 2 are connected to the ECU).

The odd thing is i have not touched any of the ignition system only to unplug connectors and plug them back in again.

the car is a Vauxhall Astra L reg (93) 1.6i 8v the coil pack is the DIS type.

 

[jonnyfishing]

Adam

Your car has an ignition amplifier incorporated in the coil pack,I have found from past experience that this is likely to be your problem,the best
way to test this is by substitution.Local car breakers should have one. I have the info for limited testing(resistance etc.) if you want it.

 

[adamwg]

Thank you jonny

Could you give me the info for testing please?

I don't want to buy another coil pack and then find out its the ECU that needs replacing.



It has just been suggested that the crankshaft sensor could be faulty. could this be the problem? I understood it that the ECU has a default map to read if it does not recieve any info from the crankshaft sensor.

so i should still be getting a spark even if the sensor is not working. Is this right?

 

[jonnyfishing]

Adam

Tests are as follows:- COIL

(the ignition coil incorporates the amplifier) note: primary resistance cannot be checked.
SECONDARY RESISTANCEignition off) check resistance between the coil H/T connections Nos 1 & 4
2 & 3
should read approx. 5700 ohms

AMPLIFIER (ignition off) remove plug.looking at plug terminals (with clip at the top)number from left to right 1 to 4
checking earth: terminal 2 and earth. should read zero ohms
checking voltage: (ignition on) terminal 1 and earth: should read battery voltage.
testing for crank sensor or wiring fault: (ignition on)
terminals 2 & 3 with engine cranking: test light should be flashing
terminals 2 & 4 with engine cranking: test light should be flashing

Hope this is is clear and helpful.

you can also access fault codes on this system if you need to .(known as flash codes) by using the "data link connection.