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running erratic after warm up???

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  #1  
Old 02-26-2007, 09:43 PM
Callipjm's Avatar
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Join Date: Feb 2007
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Default running erratic after warm up???

I have a '94 convertible. After it comes up to temp it starts idleing between 500 to 1500 rpm and sputters when accelerating. I also noticed that it seems to be running a bit hot. Thanks in advance for any help.
 
  #2  
Old 02-27-2007, 11:44 PM
mech259's Avatar
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Location: Lumberton, Texas
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Default RE: running erratic after warm up???

1st thing to do is to clean the backside throttle plates and throttle bore with carb spray and a small wire brush. Carboned up plates will make it hunt for an idle. You might also have a plug wire or spark plug breaking down to cause the misfire.
 
  #3  
Old 03-02-2007, 10:46 PM
78buckshot's Avatar
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Default RE: running erratic after warm up???

Hi mech259, sounds like the EGR valve is stuck open or partly open, during warmup the engine is getting a richer fuel micture but once it's warmed up it/s running lean and ingesting exhaust gas through the EGR causing poor idle and higher operating temp.
 
  #4  
Old 03-06-2007, 09:42 AM
mech259's Avatar
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Default RE: running erratic after warm up???

94 has a linear EGR valve and usually what happens with those is one of the actuator motors will stick the pintle open and will not idle at all or hardly. Idle hunting 90% of the time usually means coked throttle bore as the engine vacuum pulls air around the throttle plates and while the ECM is still trying to control idle, it will open and shut the IAC, hence the "hunting" effect.
 
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