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Any thoughts whats happening here?

Posted: Sat Apr 02, 2016 4:53 pm
by Charlescrown
I have had this problem for some time. After starting the car it runs for several minutes and then cuts out. I crank and restart and its fine. I am wondering if its an ignition key or relay problem but my concern is the time it takes seems to have a voltage decay period.

Re: Any thoughts whats happening here?

Posted: Sat Apr 02, 2016 6:25 pm
by Jayme
could you post up the whole log so we can load it in tunerpro?

Re: Any thoughts whats happening here?

Posted: Sun Apr 03, 2016 7:11 am
by Charlescrown
Sure thing. What I notice is as the voltage drop starts occuring the injector duration (injector BPW) looks like it goes full on saying it just ran out of fuel which co-insides with the O2 output. My guess is the pump is stopping but is it because of the voltage loss? Anyway have a look much appreciated.

Re: Any thoughts whats happening here?

Posted: Sun Apr 03, 2016 7:19 am
by Dylan
Are the injectors stock?

Re: Any thoughts whats happening here?

Posted: Sun Apr 03, 2016 7:35 am
by Charlescrown
No and I have no idea what size they are. It's a Starion TBI running 2 injectors (no ISC motor). I worked out why the voltage dropped to zero. When it cut out I restarted the car and the tiny blip to zero volts is the switch going from run to crank and the low voltage after for a couple of seconds is the battery voltage drop during cranking so the question is why is the engine starving for fuel for that short period of time? The problem looks like an intermittent fuel cut for some reason.

Re: Any thoughts whats happening here?

Posted: Sun Apr 03, 2016 7:36 am
by Dylan
If you have changed injectors and it's going lean as the voltage drops the injector opening times will need to be altered to suit.

Re: Any thoughts whats happening here?

Posted: Sun Apr 03, 2016 2:17 pm
by Charlescrown
I may have found the cause of my problem. If you look at my log and view the coolant sensor you will see this occurring. I found it on the net.

When working on 1985 and up Chrysler products, watch out for a sudden voltage increase as the engine warms up. This is normal and is produced by a 1000 ohm resistor that switches into the coolant sensor circuit when the sensor's voltage drops to about 1.25 volts. This causes the voltage to jump back up to about 3.7 volts, where it again continues to drop until it reaches a fully warmed up value of about 2.0 volts.

I am using the original Mitsubishi coolant sensor so I suspect this may be the cause of my problem.
Will get a Holden one and fit it tomorrow and see what happens.
This is a very peculiar design and I haven't come across it before it before.

Re: Any thoughts whats happening here?

Posted: Sun Apr 03, 2016 4:05 pm
by Charlescrown
Well using a genuine Holden coolant temp sensor made no difference. I think the coolant temp voltage change is the way the program displays it. The temperature value doesn't change when the voltage reading goes from 0.88 to 3.51 volts. The car cut out again but it didn't line up anywhere with the change in coolant voltage so I am convinced it's not a problem. To me it looks like the car is cutting the fuel supply causing the injectors to go full on trying to get enough fuel into the engine to keep it running. Next thing is I will monitor fuel pressure and see what happens.

Re: Any thoughts whats happening here?

Posted: Sun Apr 03, 2016 4:23 pm
by antus
Does that log file work for anyone in tunerpro with the 12p adx? I cant seem to see any data but there appears to be something in the file with a hex editor.

Re: Any thoughts whats happening here?

Posted: Sun Apr 03, 2016 4:36 pm
by Charlescrown
Antus I used the new 12P808_3bar.adx that VL400 wrote. It works fine for me.