Does not start first time and battery draining over night - 2003 156 JTS

Started by 156and33, January 09, 2022, 05:12:33 PM

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156and33

Hi

I have two possibly related issues, wonder if someone has a clue as to what is the problem or how to investigate.

Battery drain issue:  battery is in good condition (load tested).  When installed in the car the battery drains to 12.3v over night so I am keeping it on a charger.  When the interior lights are on and doors are closed battery current is 10s on milliamps.  When the lights go out, current draw from the battery goes up to 1 A.  I do not believe  there are any ignition relays in this car so am stumped as to what the cause might be ???

First start of the day:  the car fails to start every morning first go.  It usually starts OK immediately afterwards, and starts OK for the rest of the day.   It drives OK and I have no fault codes logged.  I used Multiecuscan to check: cranking RPM for crank sensor function (recently replaced), low and high high side fuel pressure (7 and 50 bar).  I have used a COP probe and each plug is getting a spark signal OK when running (still to check this during the first crank).  Any ideas?

Thanks
Duncan

Mick A

I reckon you could possibly have a problem with the key reader/immobiliser somewhere. Check when you say it cranks but won't start in the morning if the little key/lock symbol stays on the display between the tacho and the speedo binnacles.

A good auto-elec should find a current drain like that pretty quickly though.

156and33

Key light goes out normally

I am replacing all the fuses with the newer type so I can check for the parasitic current on each circuit without having to full the fuses.

I think that the issue is not strictly associated with the first start of the day, although I do have the problem always first start.  Needed a second crank this afternoon.  That was a red herring perhaps.

Craig_m67

Quote from: 156and33 on January 09, 2022, 05:12:33 PM

Any ideas?


There is a well known issue with the bulb check circuit which is located on the tacho PCB. 

Have a read /Google.  If you know somebody with a known good tach, perhaps swap them over and see what happens (they're engine specific, easy to remove/refit tho). 

( Or just disconnect the tach and see what happens to the current drain? )

https://www.alfabb.com/threads/removing-the-stupid-bulb-warning-light.678792/

'66 Duetto (lacework of doom)
'73 1600 GT Junior (ensconced)
'03 156 1.9JTD Sportwagon (daily driver)

156and33

For some time the bulb light on the dial flickers when starting, is this what you mean?
Neither brake lights or number plates bulbs (2j are blown.