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Please help,94 sc2 injectors intermittent firing,

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  #1  
Old 09-08-2012 | 08:29 AM
pauledgar's Avatar
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Default Please help,94 sc2 injectors intermittent firing,

Hi,94 sc2,automatic,was stalling off n on for a week now it wont stay running,when i can get it run,fuel psi 38 @ idle,the psi increases when i remove the vaccum line,just replaced pressure reg,coolant temp sensor,crank sensor all in the last week,,getting 5 volts at the temp sensor connector,i removed t/b cleaned it out and cleaned iac valve.i replaced fuel filter as well,the relay and fuses are good.can anyone give me some ideas,,thank you guys
 

Last edited by pauledgar; 09-08-2012 at 08:32 AM.
  #2  
Old 09-08-2012 | 10:39 PM
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where did diagnosis of intermittent injectors come from?
 
  #3  
Old 09-09-2012 | 12:41 AM
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cuz i was able to check it with a noid light and one minute its running great,next minute its not lighting up..is there a way of putting the coolant temp sensor plug on backwards,cuz tonight all i did was check for a 5 volt test at the plug and i put the plug on backwards just to see,,the car has run great since i did that,,,
 
  #4  
Old 09-09-2012 | 10:37 AM
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Originally Posted by pauledgar
cuz i was able to check it with a noid light and one minute its running great,next minute its not lighting up..is there a way of putting the coolant temp sensor plug on backwards,cuz tonight all i did was check for a 5 volt test at the plug and i put the plug on backwards just to see,,the car has run great since i did that,,,
For those of us who have never heard of something called a "Noid Light" I had to look up what one was. There are a lot of sophisticated "automotive" testing equipment I have never had and probably never will have due to lack of need to spend money on one. A noid light is plugged into the electrical harness that goes to an injector and flashes when a pulse is generated to the injector. You watch the pulsing light and assume I guess because it pulses the injector should work. No pulses means the injector will not work.

The next evaluation you have to make is whether the injector actually works or not when you can see pulses.
Of course if you don't see pulses, the injector WILL NOT WORK. At least that is the assumption I made looking for data on what one was. Which leads to the next question. What makes you think the injector is not working? If the light don't light, the injector will just sit there minding it's own business not doing anything.

The question following that was can you plug the plug on the temperature sensor on backwards.

What does that have to do with an injector?

Obviously if you plugged it in backwards you can do it.
Also if the wrong signal gets to the computer that controls how the engine runs, it is well known that the computer starts making enormous errors in running the engine.
So if I read your posting correctly?
You spent a lot of money changing parts that did nothing beneficial.
You used a noid light to determine a pulse was being generated to the injector and when it was the engine ran correctly.
You reversed the plug to the temperature sensor and solved the intermittent problem with engine operation. And every thing runs fine.
And you want some ideas?
On what?
It works. At least you said it did so I assume now that it is fixed.
My idea? Enjoy it now. You are done.
Sorry if this is not the answer you wanted I am just trying to figure out what the question was.
 
  #5  
Old 09-09-2012 | 11:51 AM
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Sounds more like a bad/intermittant connection between the ECTS and its connector -->
"...is there a way of putting the coolant temp sensor plug on backwards,cuz tonight all i did was check for a 5 volt test at the plug and i put the plug on backwards just to see,,the car has run great since i did that,,,"
 
  #6  
Old 09-09-2012 | 05:09 PM
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sorry guys,didnt mean to sound scatterbrained lol...i did replace a few things that kinda all went bad at once,,the knock sensor was out of range when i tested it,,the,fuel pressure regulator would not hold vacuum when i checked it and the coolant temp sensor was out of specs too,so i replaced all of them and replaced the fuel filter and yet it still wouldnt stay running,,so when i tested the voltage at the cts connector it was good so i decided to see if the plug would go back on ether way and it did so when i reconnected it that way the car fired up and has ran flawless ever since,,go figure,,lol anyway thanks for the help in finding my cure...have a good weekend folks,,
 
  #7  
Old 09-09-2012 | 09:25 PM
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Bottom line - you're back on the road ... enjoy the ride
 
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