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Very strange problem-Getting sensor variation on logger when car is not running.

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chanley talon

15+ Year Contributor
774
14
Nov 10, 2005
Spencer, Indiana
Im working on a freinds car 91 eagle talon . When i plug in my logger with the car not running the coolant temp sensor 02 sensor and timing all move around but the car is not running. This maybe the first case of phatom running ive ever seen or heard of. The ics also clicks! Heres the wierd thing i take his computer out and put it in my car and it runs just fine so not the ecu? I cant seem to figure this one out ive never seen this before?
IF YOU CAN HELP I WOULD APRRICATE IT GREATLY!!!!. Thats supposed to say strange!
 
Yeah pull the ECU out and open it and check the caps inside to see if they are leaking or if something else looks discolored.
 
chanley talon said:
Im working on a freinds car 91 eagle talon . When i plug in my logger with the car not running the coolant temp sensor 02 sensor and timing all move around but the car is not running. This maybe the first case of phatom running ive ever seen or heard of. The ics also clicks! Heres the wierd thing i take his computer out and put it in my car and it runs just fine so not the ecu? I cant seem to figure this one out ive never seen this before?
IF YOU CAN HELP I WOULD APRRICATE IT GREATLY!!!!. Thats supposed to say strange!

I assume you meant you put his ECU in your car.

We need a little more information about what is happening.

#1 IC stands for integrated circuit and is made of silicon layers. These CAN NOT click. something else is clicking...fuel relays maybe?

#2 is the key in the run position (I assume yes but you need to tell us details).
 
I put the computer from this broken car into mine and it starts and runs my car wich has no problems! The isc or ais i pulled it out of the throttle body turned the key forward and held it in my hand and just kept clicking and vibrating . So i took it and installed on my car no clicking or pulsing? If i plug my looger into it while the car is not running the o2 and coolant temp and air temp are all moving with the key in the on position. It started up this way this morning and will run until it gets warm and then it shuts down and wont restart?
 
I also checked the looger on diagnostics and its throwing all sorts of codes ? Egr ingintion module fuel pump relay knock sensor and those will shut off and come back on . Im going to check for water some where frying the circuts.
 
I found the problem !!! I installed the ecu from the broken car into my good running car and it would start and run fine however i plugged in my logger and it was going nuts . But before with my ecu from my good car the logger stayed normal. Wich tells me the capasitors have leaked into the circut board but have not completley killed the computer yet. So phatom running is a sign of a bad capsitor or heading on its way out.
 
so everything wasn't running fine in the other car. Glad that you found the problem.

Replacing the capacitors is fairly easy. You can do it yourself with some parts from your local electronics store.
 
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