VS Senator Starting Problems

[bob556]

OK Gents my first time on the forum, be gentle..

I have a VS Senator 185 series II, owned it from brand new....

It is now starting to show its age 185 K It has been maintained as per the book and then some and suddenly after a week off the road, not by any mechanical failure it has gone to hell and back.

Things found so far.. Fuel regualtor on back of injector frame seized, replaced it. Low fuel pressure , replaced fuel pump..

Now it is a real Pain to start, basically will try to start but does not for a long time, turns over , coughs splutters then dies, seems to be starved of fuel but pressure and volume is fine. It is like it is even becoming flooded,basically have to jump it to get it going after I flatten the battery in it. Takes about 5 minutes of continuous cranking.

Codes and modes for those that know error 12 system passed and error 31 no security signal .. Is this the cause?

Any ideas would be appreciated as I know a little but thats it. I have a mechanic who is now really confused as well. Previous symptoms were it idled badly and sometimes under load backfired. I was thinking maybe the O2 Sensor but this is a new issue.. Weh n its started its fine and when warms up even better. Battery maybe?

Any ideas would be really appreciated.

 

[Boonz]

code 31 no security signal? key might not be making contact with the reader on the ignition... bcm could be up the poo... installed the wrong fuel pressure regulator...... does it have BOSCH spark plugs by any chance???

 

[bob556]

Thanks for the response.

The Key is making Clean contact with the ignition ring,

I am getting a replacement key today anyway to see if that cures it. It is quite old now

I am running Champion Spark Plugs

The fuel regulator was a genuine Holden part and the numbers matched exactly.. Keep em coming guys, Same for the fuel pump went to a genuine part.

 

[Spaced]

I've only got a standard commodore, but it beeps when the key passes some sort of security test do you experience the same. Are you in RACQ (NRMA etc) if you are get them to test the spark all ignition devices. Just an idea

 

[bob556]

Thanks Space,

I am sure the standard commodore is the same as mine.. Labels are Labels...

I have tested all leads, checked for spark and it is going over a full diagnostic on Thursday. I think you guys may be onto something with the BCM, which I did not know about until I got to this forum,, Thanks guys... I believe if the key was old and was not registering consistantly it may be keeping the car in secure mode and only allowing it to turn over.. Now call me stupid but if the key is intermittant with its connection to the car or security system would this cause the car systems to not allow for spark to turn on the car?

i.e would the security system still be engaged / working even though key opens doors ok and is in the ignition properly as far as I can tell?

 

[Spaced]

I cannot say definately because I haven't had this problem before but it does sound really strange. If you find out what's going on here post your solution for others.

 

[bob556]

Problem Solved.

After a day under diagnostics at your local dealer, they claimed that the ECM had taken a spike and needed to be replaced... Was not sure so did some further "reading" on the ECM...

Now it turns out if your battery has charge but under crank goes below 10.5 Volts DC the ECM will not allow the car to start by not letting the ignition circuit be enabled.. Therefore the car will turn over but will not fire.

However after a couple of minutes the engine did start so why.. Its cold when I do this, after 7pm or early morning. Therefore oil is not all over the engine and its a little tight. Once you crank it the oil gets around the motor and therefore starter motor has less mechanical resistance from the motor and therefore the current required to crank the starter is less. Understanding basic electrics therefore if the resistance across the circuits is constant the voltage will go up. In my case it managed after a few minutes the voltage went over the threshold. Therfore you started to get engine firing.

Now to complicate it a little bit the ECM still allows the injectors to pump fuel therefore you get the equivalent of a flooded engine. Therefore it fires, stalls, backfires and everything else. further complicated the problem.

The final test was to leave the car for a few hours and then put an AVO / Meter across the battery terminals whilst it is cranking and you see the initial under load voltage and you can watch it come up... until it starts.... My machine was actually drawing the battery down to 9.6 volts, 0.9 volts below the threshold.

I now have a new battery in the car and all is well..

So much for the technical people at my local holden dealer...

The car had never had any of these problems before and it is only since I have stopped using it for commuting that this has occured, combine that with a Winter period and the battery being 4 years old. There you go..

So I hope this is informative to the forum and I would suggest go with the absolute basics first. By the way seek a trusted competant service agent rather than the diagnostic jockies at your local dealer.

 

[Spaced]

cheers for putting up your solution bob, battery problems are just one of those things that are hard to pinpoint. Mate had a VN that would start and would cut out when he took off swapped the battery for a new one problem solved.