Technical She just wont start....help please!

[[email protected]]

hello all. I'd appreciate any help with this problem.
About a month ago I got into my sporting cinq, turned the key, engine turns over (well the sound you get before it fires up) but wont catch. at the time I didnt believe it to be a flat battery as I could try the ignition a number of times without it even beginning to sound flat.
I checked all HT leads and anything else that may have come loose - all seemed ok.
I've replaced the starter motor today (what a nitemare!) thinking that would be the problem, turned the key - still wont start....grrrrr!
Got myself a plug remover to check state of plugs - all seem ok (light grey deposit), WD-40'd the leads - wont start.
Tried to see if its an earth fault (not sure if I was doing this right) by connecting a jump lead to the engine and other end to chassis - wont start.
When I do try to start there is nothing on the dash display to say anything is wrong.
Got a few days off work soon so would be grateful for any advice so that I can have another go then.
thanks for reading

 

[Malin Dixon]

I don't know why you changed the starter motor. From what you say the engine was turning over OK...

Anyhow, the first thing that I would check is that you are getting a spark. Take the plugs out, connect them to the leads and leave them where they are resting on the engine and turn the key.

The sound should be totally different, as the engine should turn faster and not slow down each compression. It should be whiiiiiiiiirrrrrrr with no spark plugs and nur-nur-nur-nur-nur with the plugs. If it hasn't changed when you take the plugs out, it might have no compression. Put your finger over the plug hole with the engine turning and the compression should push your finger out of the way. If not, you have major engine troubles.

There should be sparks at each plug gap. If there are none, suspect the ECU, or power to the ECU, or crankshaft sensor. It's unlikely, but possible, that both coils would have failed.

If there are sparks, and the engine turns over faster with the plugs removed, check the fuel is getting though. Remove the fuel line to the injection. Turn on the ignition and fuel should come through for about 3 seconds and stop. (It stops after then if the engine isn't running).

If there is no fuel, it is the pump or its wiring, fuse or relay, or a blockage in the pipes, or you are out of fuel.

If you have sparks and fuel, it gets more complicated and if you post again saying which is missing (if either one is), I'm sure someone will help you.

 

[[email protected]]

cool. thats all very well explained, cheers.
will try and let you know how I get on.

 

[rallycinq]

If you pulled the plugs out shortly after trying to start the car, and they were dry, I would start with the fuel side.

Cheers

D