2003 2.3 Intermittent Loss Of Spark

[andymudge]

Hello there , apologies for posting here without some site contribution but I am in a pickle.

 

I have a 2003 2.3 which has started to cut out as and when it feels like. Eventually it played up long enough for a mechanic to diagnose no spark but we cannot find out why .....

 

 

I will tell you what I know , it is presumed ignition because it doesn't stall or run badly or cough to halt etc, it literally cuts out ala key wound back into ignition on position. It doesn't appear to do this in idle and mainly when the car is warm although this may be coincidence.

 

We have replaced a Ignition relay , crank sensor , starter motor , checked with both keys , alternator , replaced plugs and leads , even plumped for a full service just in case,

coil pack. I believe the ignition barrel has been checked also, fuses all checked and 2 auto electricians scratching they're heads .......

 

All of this has been done by a local garage and the bill and the 7 weeks without the car is starting to grind.

 

Does anyone have any experience of a similar problem or any ideas that fall outside of the above.

 

I really appreciate your help in advance.

 

Andy

[xavier]

So does the key actually move? I once had a car did this and changed the fuel filter. However if you're definately sure there's no spark not going to be that. Immobiliser maybe? If keys have been checked maybe the corresponding unit in the steering column, or a broken wire from it? Sorry, clutching at straws (ideas?!) myself.

[cyborg]

Three critical items for ignition that get battery voltage when the key is on:

- the Camshaft Position Sensor, switched by the ECM

- the Coil, switched by the key

- the ECM, switched by the key and though the ECM relay “30”

 

 check all grounds ,they should be less than 1.5 ohm resistance

 

What is supposed to happen:

 

- When you turn on the ignition, the coil gets 12v though the key, the ECM gets 12v

through the Ignition relay ‘30’, and the Crank Position Sensor  gets 12v through the ECM.

 

- As the engine turns over, the CPS sends a 12v pulse to the ECM.

 

- The ECM takes this information, modifies it based on input from other sensors, and

switches 12v to ground from the coil pack. Timing of this grounding is the ignition

timing.

 

- You should hear the fuel pump run briefly when you turn on the ignition (after it

has been off for at least a couple minutes).

 

- Check for spark at the spark plugs.

 

So Start with relay 30,The coil ,Crank sensor

[andymudge]

ok thank you guys I will feed this back to the garage , and for once I will feed back results to the forum.

[andymudge]

Ok apparently relay has now been changed and we no longer start at all , my next thoughts are ECU any reason why I shouldn't do this ?

 

[BrianH]

Ok apparently relay has now been changed and we no longer start at all , my next thoughts are ECU any reason why I shouldn't do this ?

 

Its quite easy to push the contacts out of the fusebox on changing the relay which would cause that. If that relay (usually one with 30 on the top) is the culprit the led on drivers door will usually behave oddly so what is that doing and are you getting any beeping inside the car?

[andymudge]

Relay 30 has been changed , as has the cps and the coil , it will be here tonight eventually after arranging collection from the garage, I will get a boost to it and see if the LED does anything daft.

[andymudge]

have changed relay 30 , cpd and the coil already, will get it home tonight and see if the LED is blinking , im struggling to find out what the ecm is tho , is this just another phrase for the ecu please ??

[andymudge]

Ok the door LED appears to act normally as in after a few seconds it just goes out and stays out , no flashing etc. We have also deffo had a new starter motor.

[andymudge]

well no one appears interested so this will probably be my last post, recharged the battery and the car started it idled for 45 minutes no probs . I removed all the relays one by one as it was running and nothing happened. I drove off it made ten yards and died .It restarted after a bit of persuasion and cut out when I tried to move. It will only stall when moving , not idling.

[BrianH]

I think its more noone has a clue what the problem is. You mention the battery though - Just a thought have you actually ruled out the battery though? Even borrowing a known good one may be some help to diagnosis.

Edited July 12, 2013 by BrianH

[seatkid]

As mentioned earlier, a frequent problem are the contacts (receptacles) in the fusebox that you push the relays into - they can get pushed down so that the relay spade connectors does not enter fully but just touch the loose receptacle. The clue is when the car moves it dies - movement that allows the connections to seperate.

 

Check the fusebox connections under the relays by unscrewing that layer and looking behind it at those relay bases.

Edited July 13, 2013 by seatkid

[andymudge]

I removed the battery and charged it for 30 hours on an automatic charger , although it did not come up fully charged it started the beast without any hesitation. I removed all the relays one at a time including the 2nd row with our friend relay 30 on it. No relay being removed did anything major to the car one relay made the abs ligh come on , and relay 30 caused the car to lazily stall. I will check the receiving holders but im pretty sure I noted a positive 'click' as I re inserted all the relays and as far as I can gather only the fuse that controls relay 30 will cause the car to die ( which it did when I removed it ).

 

I have an auto electrician here this afternoon ( yes on a sunday ) If anyone can make a suggestion with items for him to check its greatly appreciated. Im going to suggest earthing points as a start but im still not sure what the ecm is pls .

 

As it stands it has a month before it becomes a mint galaxy for scrap.

[seatkid]

Check the Battery Junction Box  (in front of battery that red +ve lead from battery goes into).  These are notorious for bad crimps on the top and second from top leads on the RHS.  Open top and look for evidence of overheating/scorching/distortion. Link

[BrianH]

I'd try swapping the battery as well if that doesn't work. Trouble is items like the immobiliser will play up if not getting the right voltages etc. Even if it does start it doesn't mean the battery is acutally all that good, and your reporting the charger showing it doesn't charge fully would suggest its not great. Even if you have to borrow one off another car to try it its got to be worth a try.

[andymudge]

Ok auto sparky was a scrub , plugged in and said theres no faults and said it must be the ignition coil pack , i explained this had already been changed but hey. I bought another new one and fitted it , it of course started but died whilst in motion as always. Now the vehicle will not try to start, not even try to turn over. I had the battery tested as ok , but im going to loan a battery from my pals tdi galaxy mk2 tomorrow to see if it makes a diff.

[BrianH]

ECM i think you will find means electronic control module rereading whats been said already. I would personally understand that to be meaning the same thing as the ecu although its more of a generic term. If you have one of the diagnostic plug in boxes (the standard obd2 readers you can pickup from ebay etc for about £10 will work for the ford engined varients) then see if it will connect when it stalls. If it doesn't connect this would point towards the immobiliser area (the ecu will only connect when the immobiliser is deactivated by seeing a key with the ignition on). If it will connect some of the time but not others i'd start looking at that although it seems you have already ruled out relay 30.

 

Its worth taking the fuseboard with that load of relays out and really making sure visually that the connections are properly inserted - the relays will still click with a cable out as theres multiple connections on them.

[viperclive]

I had a similar problem, sorted by the AA man, it was a bad connection on a lead between starter motor working back to alternator.

[andymudge]

hey guys , thanks for the input , I have had the immobiliser removed professionally already so I can definitely rule that out , im buying an small obd reader today so I can plug in at various stages of the fault to see if we can get any fault codes at all. I will check again leads and look for a connection between starter and alternator.

[andymudge]

Ok battery swap no go go . however removing fuse 4 and replacing did seem to make the car start 4-5 times on the bounce , then it started with a bit of a fuse box wiggle but with no real consistency. In the past some repairs must have gone on behind here as there is a lot of taped joints etc. Is it feasible to completely overhaul all connections into the fuse board or maybe even replace the loom ?

[cyborg]

Check your earth straps also wires in tailgate & doors

Edited July 19, 2013 by cyborg