C4 ZR-1 Discussion General ZR-1 Corvette Discussion, LT5 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track

Low RPM stumble/miss

Old 05-05-2005, 11:13 AM
  #1  
ShawnZR-1
Race Director
Thread Starter
 
ShawnZR-1's Avatar
 
Member Since: Oct 2001
Location: Canton GA
Posts: 12,736
Received 78 Likes on 31 Posts
Cruise-In III Veteran
Cruise-In IV Veteran
Cruise-In VI Veteran
St. Jude Donor '03-'05-'06-'10-'11-'12

Default Low RPM stumble/miss

Help me out here, it seems my beast has developed an attitude at low RPM's.
It seems to happen under the following conditions:
Key on or off,
Temps normal
RPM less than 1500RPM
Throttle position >25%
No Codes set.

As soon as it gets over 2K, it pulls to the stratosphere, all the way to 7000+.

I was trying to think if it did it at all before I installed the headers, but I can't say for sure. I don't think it did, but I can't swear to it.
Is false knock a possibility? I haven't scanned it yet but it seems that even last year when I had the stock manifolds on it, I had some knock counts. I run 93 all of the time.

Ok, hit me up with the ideas!
Old 05-05-2005, 01:42 PM
  #2  
Jeffvette
Race Director
 
Jeffvette's Avatar
 
Member Since: May 2000
Location: No more yankee my wankee, the Donger is tired!
Posts: 17,101
Likes: 0
Received 1 Like on 1 Post
Default

Check plugs for fouling
Check plug wires to make sure they are seated
Old 05-05-2005, 03:14 PM
  #3  
ShawnZR-1
Race Director
Thread Starter
 
ShawnZR-1's Avatar
 
Member Since: Oct 2001
Location: Canton GA
Posts: 12,736
Received 78 Likes on 31 Posts
Cruise-In III Veteran
Cruise-In IV Veteran
Cruise-In VI Veteran
St. Jude Donor '03-'05-'06-'10-'11-'12

Default

Originally Posted by Jeffvette
Check plugs for fouling
Check plug wires to make sure they are seated
I checked the wires last night, I'll check the plugs this weekend when the car has a chance to cool enough. FWIW, the plugs and wires were the first things I thought of.
Old 05-05-2005, 03:28 PM
  #4  
DDSLT5
Team Owner
 
DDSLT5's Avatar
 
Member Since: Jul 2002
Location: This city NEVER sleeps! Frank's back yard!
Posts: 35,628
Received 68 Likes on 40 Posts

Default

Originally Posted by ShawnZR-1
I checked the wires last night, I'll check the plugs this weekend when the car has a chance to cool enough. FWIW, the plugs and wires were the first things I thought of.

Did you use an ohm meter to check the wires? I had one that was inconsistent, the motor still ran reasonably fine, and the wire itself looked perfect, but the connection was frayed at some point - if the wires are original, time to replace them.
Old 05-05-2005, 04:19 PM
  #5  
ShawnZR-1
Race Director
Thread Starter
 
ShawnZR-1's Avatar
 
Member Since: Oct 2001
Location: Canton GA
Posts: 12,736
Received 78 Likes on 31 Posts
Cruise-In III Veteran
Cruise-In IV Veteran
Cruise-In VI Veteran
St. Jude Donor '03-'05-'06-'10-'11-'12

Default

I replaced the wires around October last year, they're not the originals. I only checked to make sure they were seated. I didn't go under the plenum to check them end to end yet. I have a feeling it's a mucked up plug, but I haven't had a chance to pull them. The car doesn't cool down enough at night and in the morning, well, I do have to go to work. I'll yank them out this weekend and see.
Old 05-09-2005, 11:30 AM
  #6  
ShawnZR-1
Race Director
Thread Starter
 
ShawnZR-1's Avatar
 
Member Since: Oct 2001
Location: Canton GA
Posts: 12,736
Received 78 Likes on 31 Posts
Cruise-In III Veteran
Cruise-In IV Veteran
Cruise-In VI Veteran
St. Jude Donor '03-'05-'06-'10-'11-'12

Default

Update: #2 plug was fouled as all get out. Black and carboned up. Runs like a purring kitten now! God, I love simple fixes!
Old 05-09-2005, 02:42 PM
  #7  
Jeffvette
Race Director
 
Jeffvette's Avatar
 
Member Since: May 2000
Location: No more yankee my wankee, the Donger is tired!
Posts: 17,101
Likes: 0
Received 1 Like on 1 Post
Default

Glad to see you found a simple fix
Old 05-09-2005, 05:15 PM
  #8  
ZZZZZR1
Burning Brakes
 
ZZZZZR1's Avatar
 
Member Since: Jun 2001
Location: Auburn WA
Posts: 1,149
Likes: 0
Received 1 Like on 1 Post

Default

Originally Posted by ShawnZR-1
Update: #2 plug was fouled as all get out. Black and carboned up. Runs like a purring kitten now! God, I love simple fixes!
Good job, but...what caused the fouling? Bad injector?
Old 05-09-2005, 05:23 PM
  #9  
DDSLT5
Team Owner
 
DDSLT5's Avatar
 
Member Since: Jul 2002
Location: This city NEVER sleeps! Frank's back yard!
Posts: 35,628
Received 68 Likes on 40 Posts

Default

Originally Posted by ZZZZZR1
Good job, but...what caused the fouling? Bad injector?

BAD ATTITUDE!!!

Get notified of new replies

To Low RPM stumble/miss



Thread Tools
Search this Thread
Quick Reply: Low RPM stumble/miss



All times are GMT -4. The time now is 09:53 PM.