none starter

AHughes · Post by **AHughes** » 08 Jul 2003, 01:14

Am pretty new to car DIY. I have an N reg 1.8i 16v Xantia.
While back failed to start, faulty alternator, took it out, new coils, brushes etc,,, 2 months later wont start, new battery, old one dead... but no still wont start,, starter motor gone, new one in (bugger of a job!).
Been ok for 2 weeks, now wont start! Am at my wits end.
Symptoms, turns over ok , good current from alternator.... almost feels like its flooded, but has failed to start on 3 occassions now, only with persistance do I get it going.
But have reached the end of my limited expertise.
In other words to all you worlds DIY mechanics out there... HELP!

jeremy · Post by **jeremy** » 08 Jul 2003, 02:59

can we assume that its turning over nice and fast and that the battery is fully charged?
Jeremy

AHughes · Post by **AHughes** » 08 Jul 2003, 03:07

Once I have it running, runs nice and fast, had a 40 minutre run in it. Battery is fully charge, when I try to restart it turns over & over without ignition, though pumping helps. Kind of like my first car (Nissan Sunny)

AndersDK · Post by **AndersDK** » 08 Jul 2003, 03:56

Sounds to me like coldstart problems - i.e. the "choke" function is at fault - either overriching or leaning the fuel at engine start.
The ECU uses a separate engine temp sensor - usually located at end of cylinderhead over flywheel - behind thermostat housing. It's fitted with a 2pole blue connector.
If this sensor/cabling fails - the ECU thinks the engine is ice-cold.
The sensor should read approx 3K ohms if tested with ohmmeter - but usually they are disrupted when at fault.

jeremy · Post by **jeremy** » 08 Jul 2003, 04:06

Anders
My reading of Andrews problem is that its a hot start problem. I asked my original question in the hope that we could eliminate battery/starter/alternator etc and in his answer Andrew says he drove it for 40 minutes and then couldn't re-start.(not what I was expecting him to say!)
Jeremy

AndersDK · Post by **AndersDK** » 08 Jul 2003, 04:16

Agree Jeremy [^]
- still - if the temp sensor is at fault - the engine will DEFINATELY be overriched on hot starts.
No problem once running - the Lambda sensor will then signal the ECU to hold back the fuel.
- like the engine system allways attempt to do a cold start - no matter what.

wheeler · Post by **wheeler** » 08 Jul 2003, 04:30

the sensor for the cold start is usually green,the blue one is for the temp gauge.the resistance value you get from it depends on its temperature,at 3 kOhms the temp would be about 17 degrees C.it's an NTC sensor which means its resistance goes down as it's temp increases.

ghostrider · Post by **ghostrider** » 08 Jul 2003, 04:46

Andrew, the other thing you could check is the TDC sensor which generates all the timing info for the ECU, I had an intermittent one on a CX once, took me ages to work out what it was, but the symptoms were very similar to the ones you describe. The sensor if its like the BX is at the back of the engine flywheel end, Anders can probably confirm location as I've not looked for mine yet
________
VAPORIZER VOLCANO

alan s · Post by **alan s** » 08 Jul 2003, 05:05

Could I suggest a bit more detail so we know where we're going?
For instance, with the battery, alternator, starter motor problems, is there any similarity to the present problem? Was it just winding to a standstill & that is why these components were changed?
Confirm whether it's hot start, cold start or both where the problem arises.
Have the injectors been cleaned and what condition are the spark plugs in? How does the car run overall; is it smooth, jerky, rough at idle, miss under load?
Basically eliminate all the basics before going down the deep & mysterious paths is what I am meaning.[:D]
Alan S

AHughes · Post by **AHughes** » 08 Jul 2003, 11:53

The components have been changed out of necessity, alternator, battery, starter motor. Each tested first to make sure there was a fault. I won't have time this morning to check the plugs, though they were fine a month ago and the injectors seem ok. The car runs well once going. Idle constant, smooth run, fine underload.
I will check the relevant sensors, (once I find them) to make sure they are functioning.
I should mention that it starts with "relative" ease from cold it is once the engine is hot that the starting issue becomes more prominent.
Thank you for all the advice thus far, will see what I can see.

jeremy · Post by **jeremy** » 08 Jul 2003, 13:39

sounds as though Anders is right now we get that information!
jeremy

vanny · Post by **vanny** » 08 Jul 2003, 15:23

As a long shot it may be worth a spot of spring cleaning first, ie clean the battery connections and lube, then clean the accesible sensor connections (such as the temp sensor etc). Strangely enough ive worked on three Xantias that had alarm problems (would go off when started for no reason, they werent set), in all three cases cleaning the battery terminals fixed the problem!!

mbunting · Post by **mbunting** » 08 Jul 2003, 17:15

Our AX came to us with "starting problems" very similar to yours.
Once running, it would run for the duration of the journey.
From stone cold, it was fine.
When warm, it had problems starting, expecially when it had been left for 10 - 30 minutes to cool, and then it would flat-spot, and you could smell a slight hint of neat petrol from the exhaust - as if on choke.
To cut a long story short, I suspected it was temperature related, and got an ecu reader from a well known high-street store for £20. This reported that the coolant temperature sensor was faulty, I replaced this, and the car was absolutely fine in all conditions, and gave us an extra 10 - 15mpg ( because it could come out of the "warming up" choke cycle ).

AHughes · Post by **AHughes** » 19 Jul 2003, 13:38

Thanks for your advice guys, sorry for not getting back but been ill.
Had a chance to look at it, wont even start at all now, got desperate and called the AA. He found am loosing voltage from the negative terminal of the Alternator to the negative of the battery, about 6 volts, positive is ok.
Tried locating where this is happening but no joy.
There is one cable I noticed with a white connector, single prong, that is not connected to anything, nor can I find a home for it (located near the lead going to the ignition coil)
I have a feeling am going to need the services of an auto electrician.
Thanks again guys.