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Re: VR V8 Problem

Posted: Thu Apr 24, 2014 8:48 am
by Charlescrown
When the engine cuts out are you taking your foot off the throttle? because the TPS voltage goes down to .22 volts? Way too low. Looks to me like a voltage supply problem to that part of the circuit but without knowing what else is fed from the same supply from the ECU? The map does as it should going to almost 5 volts and the injectors go to 10ms. The supply to the ECU is a little low when the engine cuts out to around 11.5 volts.
I would run a separate 12 volt supply to the ECU and if that doesn't work swap the ECU.

Re: VR V8 Problem

Posted: Thu Apr 24, 2014 9:40 am
by AJS85
Yeah foot is completely off throttle.. the lights on the dash also dim just before the engine stalls if that helps.

Re: VR V8 Problem

Posted: Thu Apr 24, 2014 11:12 am
by vs ss
Make sure all the earth wires are ok. The battery earth wire is ok where it goes onto the power steering bracket,the eyelet on the inner guard next to the battery as well.
There is also a non insulated type wire that goes from under the alternator to the body and check the pcm earths which are on the back of the passenger side head and the front of the alternator bracket.
All worth a check just incase.

Re: VR V8 Problem

Posted: Thu Apr 24, 2014 1:28 pm
by Charlescrown
Just had another look at the log and your air temp is extremely high. Not something silly like an EGR valve fully open or valve timing way out? Try another log and when it cuts out push the accelerator pedal to the floor and get a log of it. It should go to around 5 volts.

Re: VR V8 Problem

Posted: Thu Apr 24, 2014 7:08 pm
by AJS85
Thanks for the reply's.
I will have a good look over the earths tomorrow as well as change out the O2 sensor and I will create some more logs and see what happens when the engine is cold.

Re: VR V8 Problem

Posted: Thu Apr 24, 2014 8:26 pm
by vs ss
The o2 sensor might be ok as if the car is only idling on the v8 even if the engine is hot most of the ones ive seen shut down due to not enough heat in the pipe.
They are non heated o2 sensor so it wont do much while the engine is cold and especially while its idling.

Re: VR V8 Problem

Posted: Fri Apr 25, 2014 6:45 am
by Charlescrown
I don't think there is anything wrong with the o2 sensor. It's swinging up and down nicely as it should. It swings up to 900mv when the problem occurs. I still think it is an ECU problem but some longer logs will help.

Re: VR V8 Problem

Posted: Fri Apr 25, 2014 1:42 pm
by AJS85
Here is a longer log.
long_log.xdl
(510.24 KiB) Downloaded 184 times

Re: VR V8 Problem

Posted: Fri Apr 25, 2014 2:35 pm
by vs ss
It is commanding the iac to open ok but is the iac working?
Just seems like its stuck shut.

edit: just had another look and you have a speed sensor code 24 set then clears towards the end then sets again.

Re: VR V8 Problem

Posted: Fri Apr 25, 2014 5:13 pm
by Charlescrown
I noticed that in your log the prom ID keeps changing. Not being an expert maybe someone else might like to comment.
I have attached a log of my car so you can do some comparisons.