Notices
C4 General Discussion General C4 Corvette Discussion not covered in Tech

LT1 runs, but runs rough..

Old 08-09-2012, 11:53 PM
  #1  
mazdaverx7
Le Mans Master

Thread Starter
 
mazdaverx7's Avatar
 
Member Since: Sep 2009
Location: Vermilion OH
Posts: 5,552
Received 558 Likes on 399 Posts

Default LT1 runs, but runs rough..

on my 94 6spd coupe, i originally was led to believe the opti spark unit was bad, so i replaced it. the engine did not run and after some trial and error, i replaced the ICM and the engine fired right up! its running a little rough and feels slightly down on power under acceleration. it has a solid idle but i can tell that there is a miss. the right side converter was glowing almost white and then after sitting for a minute with the engine off, glowing red after my first test drive. i have not checked the timing and did not check for crossed plug wires as i have to be up at 5am for work and its late, lol. any ideas other than timing or crossed wires as to why the engine may run rough and cause the right converter to glow white?
Old 08-10-2012, 02:43 PM
  #2  
stag15m4
Intermediate
 
stag15m4's Avatar
 
Member Since: Apr 2011
Location: North Carolina
Posts: 43
Likes: 0
Received 0 Likes on 0 Posts
Default

The converter converts unburned hydrocarbons, so I would think that a spark plug is not firing correctly. It may even be cracked porcelain that causes the plug to arc prior to sparking in the combustion chamber.

The plugs are just a guess. I'm not a mechanic, but it makes sense to me.. The catalytic converter is working too hard and getting super hot. Either there is a cylinder that is not firing or the converter is stopped up.
Old 08-10-2012, 04:18 PM
  #3  
sailorsteve
Drifting
Support Corvetteforum!
 
sailorsteve's Avatar
 
Member Since: Jun 2010
Location: Westerly RI
Posts: 1,851
Received 7 Likes on 7 Posts

Default

Any codes?
Old 08-10-2012, 08:54 PM
  #4  
93Rubie
Safety Car
 
93Rubie's Avatar
 
Member Since: Sep 2010
Location: Indiana PA
Posts: 3,750
Received 185 Likes on 129 Posts

Default

You have a miss fire fix it before you damage the cats (causing other problems). That raw unburnt fuel is overheating the cats, which can and will cause them to melt down, creating a potential blockage.

Spark checkers are cheap. Inline off the coil and at every plug wire. If all ok, and good strong spark there. You may have bad plugs.
Old 08-10-2012, 09:17 PM
  #5  
mazdaverx7
Le Mans Master

Thread Starter
 
mazdaverx7's Avatar
 
Member Since: Sep 2009
Location: Vermilion OH
Posts: 5,552
Received 558 Likes on 399 Posts

Default

the issue after i got the engine started ended up being crossed plug wires on the opti. i took the time to replace the plugs and wires on the right side of the engine and the engine started and ran perfectly! i hope to get to the left side of the engine and replace the plugs and wires on that side as well. gotta figure out how to get to the wires on the opti on the left side of the engine..today was my first real drive in my new 94 and i can tell you its one hell of an AWESOME car!!! what an improvement over my 84! now, if the clutch weren't slipping, i could really feel how well the car accelerates!
Old 08-10-2012, 09:31 PM
  #6  
Frizlefrak
Race Director
 
Frizlefrak's Avatar
 
Member Since: Dec 2000
Location: El Paso Texas
Posts: 17,551
Received 23 Likes on 13 Posts

Default

Originally Posted by mazdaverx7
today was my first real drive in my new 94 and i can tell you its one hell of an AWESOME car!!! what an improvement over my 84! now, if the clutch weren't slipping, i could really feel how well the car accelerates!
Yeah...I went from an 84 to a 95. Felt the same to 4K rpm....after that, the LT1 is like night and day difference. Fix the damn clutch and enjoy the thing.
Old 08-10-2012, 09:35 PM
  #7  
mazdaverx7
Le Mans Master

Thread Starter
 
mazdaverx7's Avatar
 
Member Since: Sep 2009
Location: Vermilion OH
Posts: 5,552
Received 558 Likes on 399 Posts

Default

gonna have to research to find the best clutch at a reasonable price. i don't want to cheap out and risk shattering the friction surface on a cheap disc during some spirited driving..

Get notified of new replies

To LT1 runs, but runs rough..



Thread Tools
Search this Thread
Quick Reply: LT1 runs, but runs rough..



All times are GMT -4. The time now is 03:51 PM.