1st Generation S-series (1983-1994) Tech Discuss 1st generation S-series (1983-1994) general tech topics here.

Horrible Misfire/Idle Problem/Spark Plug Problem

Thread Tools
 
Search this Thread
 
  #1  
Old 03-29-2007, 02:48 PM
Daytripper540's Avatar
Thread Starter
Join Date: Mar 2007
Posts: 8
Daytripper540 is an unknown quantity at this point
Default Horrible Misfire/Idle Problem/Spark Plug Problem

The 1993 GMC Jimmy has been idling very very rough. When you crank it there is a very apperant smell of gas, the exhaust smells really bad, the spark plugs are covered in a black soot, and it gets horrible gas mileage. The exhaust is so bad that when you crank it and let it idle, the grass under the tip will turn black. It sounds like it has a big *** cam in it.
How do I fix this?
 
  #2  
Old 03-29-2007, 03:15 PM
swartlkk's Avatar
Administrator
Join Date: May 2005
Location: Waterloo, NY
Posts: 41,137
swartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond repute
Default RE: Horrible Misfire/Idle Problem/Spark Plug Problem

Sounds like either the catalytic converter has gone bad, or you have an internal fuel leak. Is this a CPI motor or TBI? I'm leaning towards an internal fuel leak, but if an internal fuel leak is allowed to go on too long, it will lead to converter failure.
 
  #3  
Old 03-29-2007, 03:54 PM
Daytripper540's Avatar
Thread Starter
Join Date: Mar 2007
Posts: 8
Daytripper540 is an unknown quantity at this point
Default RE: Horrible Misfire/Idle Problem/Spark Plug Problem

Converter has already failed and has been cut out. It's CPI, I think.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
4.3l trouble
2nd Generation S-series (1995-2005) Tech
10
04-07-2019 06:54 PM
Ron Snell
2nd Generation S-series (1995-2005) Tech
12
12-21-2012 10:21 AM
Yankee Team1020
2nd Generation S-series (1995-2005) Tech
23
08-03-2011 08:05 AM
futuredoc
2nd Generation S-series (1995-2005) Tech
4
06-28-2010 02:50 PM
boulonman
2nd Generation S-series (1995-2005) Tech
4
03-05-2007 05:10 AM



Quick Reply: Horrible Misfire/Idle Problem/Spark Plug Problem



All times are GMT -5. The time now is 12:58 PM.