LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

Trying to pinpoint a miss.

Thread Tools
 
Search this Thread
 
Old 09-10-2014, 04:49 PM
  #1  
Registered User
Thread Starter
 
Red97LT1's Avatar
 
Join Date: Sep 2001
Location: Western North Carolina
Posts: 831
Trying to pinpoint a miss.

I'm not sure what is going on with my 97 Z28.I had a bad injector causing a miss,so instead of trying to find out which one,I replaced all of them.

I have also replaced all the plugs two weeks ago.

I started the car and it idled ok for a few minutes and had a little smoke coming out the exhaust pipes (really didn't smell like anything), then it started to have that slight miss. I took the car for a 2 mile drive and it ran fine,until I come to a stop and then I could feel the miss again. At no time did I notice smoke coming out from behind the car.

I come home,put it in park and the miss is there as is the little bit of smoke when I hit the throttle.

I'm not showing any codes at the moment.

My mechanic is out of the shop for a week,so I can't take it to him for a while. Anybody have any ideas as to what to check? Would a vacuum leak cause this sort of behavior? Thanks
Red97LT1 is offline  
Old 09-10-2014, 05:17 PM
  #2  
Registered User
 
raroz28's Avatar
 
Join Date: Feb 2005
Location: Metro Detroit, MI
Posts: 1,326
Re: Trying to pinpoint a miss.

what color is the smoke
raroz28 is offline  
Old 09-10-2014, 05:37 PM
  #3  
Registered User
Thread Starter
 
Red97LT1's Avatar
 
Join Date: Sep 2001
Location: Western North Carolina
Posts: 831
Re: Trying to pinpoint a miss.

White,maybe sort of a grayish white.
Red97LT1 is offline  
Old 09-10-2014, 06:34 PM
  #4  
Administrator
 
Injuneer's Avatar
 
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,650
Re: Trying to pinpoint a miss.

How did you determine a bad injector was causing the original miss? Were those injectors the originals, or has the engine been modified to the extent it required larger injectors? What size and brand did you recently install?
Injuneer is offline  
Old 09-10-2014, 06:41 PM
  #5  
Registered User
Thread Starter
 
Red97LT1's Avatar
 
Join Date: Sep 2001
Location: Western North Carolina
Posts: 831
Re: Trying to pinpoint a miss.

Originally Posted by Injuneer
How did you determine a bad injector was causing the original miss? Were those injectors the originals, or has the engine been modified to the extent it required larger injectors? What size and brand did you recently install?
My mechanic and I could smell the gas in the exhaust fumes and said that the way it was acting was the sign of a bad injector. After replacing them,the gas smell is no longer there. I can't really smell anything now in the exhaust fumes.

The injectors were the originals (106k miles). I just decided to replace them all.

Car is stock and I put stock 24Lb Bosch III injectors back in.
Red97LT1 is offline  
Old 09-12-2014, 07:25 AM
  #6  
Registered User
 
horridohutch's Avatar
 
Join Date: May 2011
Posts: 61
Re: Trying to pinpoint a miss.

I am thinking if you replaced the injectors and plugs.... still have the miss and smell unburnt fuel, maybe the plug wires are the next logical thing to check. I recently had a similar situation and though the wires were fairly new, they were the culprit. One was grounding out intermittantly.
horridohutch is offline  
Old 09-12-2014, 09:06 AM
  #7  
Administrator
 
Injuneer's Avatar
 
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,650
Re: Trying to pinpoint a miss.

Originally Posted by horridohutch
I am thinking if you replaced the injectors and plugs.... still have the miss and smell unburnt fuel, maybe the plug wires are the next logical thing to check. I recently had a similar situation and though the wires were fairly new, they were the culprit. One was grounding out intermittantly.
He says the fuel smell in the exhaust has been eliminated.

Try scanning it with a scanner with "GM Enhanced Parameters", which will allow you to pull up the misfire count by individual cylinder.
Injuneer is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
KYWes
LT1 Based Engine Tech
8
06-14-2022 06:52 AM
jayblev95
LT1 Based Engine Tech
11
09-26-2015 09:44 PM
CamaroSS30thAnn
General 1967-2002 F-Body Tech
13
09-08-2015 04:43 PM
Javi Fierros
General 1967-2002 F-Body Tech
9
06-01-2015 11:41 AM
96z
LT1 Based Engine Tech
1
10-20-2003 09:21 PM



Quick Reply: Trying to pinpoint a miss.



All times are GMT -5. The time now is 05:55 PM.