RoverGauge sudden drastic main voltage drop ?
Discussion
Trying to help out a fellow Chim owner whose car idles for 7-8 minutes then dies.
Early 4.3 litre on Map 2 (non catalyst) no cats or lambda's.
His thread is here Titled "Help"
https://www.pistonheads.com/gassing/topic.asp?h=0&...
I want to focus on one aspect that is puzzling - Namely Sudden Main Voltage Drop
I've looked at the RG data for him and noticed that the car runs fine and all parameters appear to be OK then suddenly the 'Main Voltage' drops from 13v to 7v.
This appears to kick the TPS and MAF values to jump up (nothing touched by owner) then it all goes into melt down, fuel map column/rows start jumping all over the place then it dies.
Here is what happens in last 90 seconds of running at idle, no touching of throttle etc by owner.
At data point 30 the voltage flutters a little, MAF & TPS go haywire engine runs up to 4K then stabilises till data point ~80 when voltage flutters a little again then suddenly has major drops and engine dies.
I have suggested checking earth in cabin by gear stick and the engine to chassis earth plus battery terminals and the ECU main plug.
Whats your thoughts /
Early 4.3 litre on Map 2 (non catalyst) no cats or lambda's.
His thread is here Titled "Help"
https://www.pistonheads.com/gassing/topic.asp?h=0&...
I want to focus on one aspect that is puzzling - Namely Sudden Main Voltage Drop
I've looked at the RG data for him and noticed that the car runs fine and all parameters appear to be OK then suddenly the 'Main Voltage' drops from 13v to 7v.
This appears to kick the TPS and MAF values to jump up (nothing touched by owner) then it all goes into melt down, fuel map column/rows start jumping all over the place then it dies.
Here is what happens in last 90 seconds of running at idle, no touching of throttle etc by owner.
At data point 30 the voltage flutters a little, MAF & TPS go haywire engine runs up to 4K then stabilises till data point ~80 when voltage flutters a little again then suddenly has major drops and engine dies.
I have suggested checking earth in cabin by gear stick and the engine to chassis earth plus battery terminals and the ECU main plug.
Whats your thoughts /
That's stuff I wasn't fully aware of, very useful.
Particularly this...
Particularly this...
Steve_D said:
and a number of other parts all earth at the front of the timing cover near the oil pressure switch/senders.
Steve
As its happening at approx 7-8 minutes after start up and it all runs smooth till then I postulate it is heat related, thus that earth point may be a bit shakySteve
Posted over on fb
No wonder the data looked odd.
quote
[i]
Simon Harry Firth
I gave in and sent it to my mechanic. He’s found the issue. It was a couple of frayed wires to the temp sensor. As she was heating up it caused them to short and send the temp sensor crazy. Repaired the wires and a new sensor. Problem seems to be solved. Thanks everyone for all the help. Now trying to get some time in her before I put her away for winter.
[/i]
Unquote
No wonder the data looked odd.
quote
[i]
Simon Harry Firth
I gave in and sent it to my mechanic. He’s found the issue. It was a couple of frayed wires to the temp sensor. As she was heating up it caused them to short and send the temp sensor crazy. Repaired the wires and a new sensor. Problem seems to be solved. Thanks everyone for all the help. Now trying to get some time in her before I put her away for winter.
[/i]
Unquote
blitzracing said:
What gets me is the temperature readings are completely steady in the logs when it goes wrong , so I cant see how a shorted temp sensor would cause the fault. Time will tell.
Yep thats exactly what I thought. I went back to the logfiles and water temp in RG is completely normal as is fuel tempGassing Station | Chimaera | Top of Page | What's New | My Stuff