LT1/LT4 Tech 1993-1997

I'm stumped

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  #11  
Old 01-11-2011, 12:26 AM
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I checked the cat as in I took it off and inspected it. No signs of dilapidation or deterioration. The honeycomb wasnt discolored and very much intact. But I was thinking, how would an electrical fault cause my engine to idle funny? Another thing to add to the mix I forgot to mention is that the car has a hard time starting as of recently, not all the time though. And when it does it takes about 3-5 seconds on the starter to get it going. Whenever it does that the idle surges up to about 2000 Rpm's and then slowly settles back down to regular idle
 
  #12  
Old 01-11-2011, 01:20 AM
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Did I mention the fuel pump?

OH and electrical issues such as bad grounds can easily cause issues with your engine. Think about it the computer, ignition, and just about everything else in the car needs the electrical system. If the ground is bad the system that uses that ground will either not work or it will find another ground through another circuit which will interfere with that system as well. Ground does not have to be the - side of the battery either it simply has to be something electrical that has a lower potential than the source.

A bad ground can cause the computer to read wrong or give the wrong command, it can put noise on a sensor which could give a wrong reading, the injector may not fire properly since the ground may not be steady... etc the list goes on and on. You want to see some strange things happen remove some grounds. But be careful with this you can damage other components.

Massey
 
  #13  
Old 01-11-2011, 01:43 PM
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Well I have a brand new fuel pump in it from just a few months ago. I'll check the grounds tonight when I get off work
 
  #14  
Old 01-15-2011, 01:25 AM
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Clean your IAC and the IAC port that may help.
 
  #15  
Old 01-16-2011, 11:21 PM
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I cleaned the IAC valve a while ago, but I'm positive I found the problem. At night I looked at the engine and if you catch it at the right angle you can see the spark plug wire arcing. Will change the wires tomorrow
 
  #16  
Old 01-16-2011, 11:45 PM
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I had a similar issue and it was my opti
 
  #17  
Old 01-18-2011, 09:30 AM
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Alright I took off my wires and they all look like they are in great condition. And the only reason I could see the wire arcing is because of the heat shield. Without the heat shield it doesent arc but still grounds out, causing the Idle to stumble. Would that still be bad wires?
 
  #18  
Old 01-18-2011, 11:03 AM
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could be a cracked insulator on the plug. did you drop any of them when installing
 
  #19  
Old 01-19-2011, 12:19 AM
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Not that I remember, but it was a while ago. I work 16 hour days so I'm going to have to wait until the weekend to try anything. I'll replace the wire and if that doesent work I'll try the plug. I'll update asap
 
  #20  
Old 01-19-2011, 06:40 AM
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you need to verify the basics as everyone is pointing out.

FWIW, when my O2's go bad, the A/F is so messed up that one minute it's elan as heck and the next it's rich as anything. The engine would stutter a little as you mention because it would basically be fuel starved when sitting at idle and fall on its face a little when you punch the gas. That's why I saw gauges bounce like you describe. The engine was in essence cutting out.
 


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