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

94 z28 running rough when warmed up

Thread Tools
 
Search this Thread
 
Old 09-05-2010, 12:27 AM
  #1  
Registered User
Thread Starter
 
72 RS camro 4SP's Avatar
 
Join Date: Oct 2009
Location: south jersey
Posts: 31
94 z28 running rough when warmed up

My 94 camaro was idling rough and was missing when I accelerate it.I already
replaced the fuel filter and ran fuel injection cleaner through it and the air filter is fine.Then I disconnected the right o2 sensor now it idles smooth and accelerates great but after ten minutes of driving I am getting the ses light on and light on the accelerating and braking around town about 8 to 9 mpg for gas mileage.Could it be the left o2 sensor and or the maf sensor?.Somebody said autozone in the forum could it read that it would pick up two different codes if it is that?
72 RS camro 4SP is offline  
Old 09-05-2010, 08:49 AM
  #2  
Administrator
 
Injuneer's Avatar
 
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,824
You'll get the SES light and at least one code for the disconnected O2 sensor. Did you have an SES light BEFORE you disconnected the sensor?

Reconnect the sensor, pull the "PCM BAT" fuse in the end of dash panel for 30 seconds to clear the codes. Drive it normally until the SES light comes back on. Find someone with an OBD-I scanner to pull the code(s). Usually shops like AutoZone can only scan OBD-II (96 and up) PCM's, so they might not be able to help you.

If you have a laptop, you can get a cable and free scanning software that will allow you to read the codes, and run a data log of the sensors and PCM parameters as you drive. Often, the data log will point you in the right direction. If interested, I'll post the links for the cable and free software.
Injuneer is offline  
Old 09-06-2010, 07:40 AM
  #3  
Registered User
Thread Starter
 
72 RS camro 4SP's Avatar
 
Join Date: Oct 2009
Location: south jersey
Posts: 31
running rough

Yes I was getting the ses light after the same amount of time with o2 sensor connected.It seem to clear up the problem of running rough after disconnecting the o2 sensor.Yes I would be interested in the cable and the software for the laptop to scan the sensors.I will definitly give it a try.I appreciate the info.
72 RS camro 4SP is offline  
Old 09-06-2010, 08:26 AM
  #4  
Administrator
 
Injuneer's Avatar
 
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,824
You can also use a "real" OBD-I scanner, like the one make by Auto Xray. Just don't try the $30 Actron "code scanner", because that just shorts the pins in the ALDL connector to flash the codes on the SES light, but 93 was the last year that would work.

FreeScan - "free"

http://www.andywhittaker.com/ECU/Fre...0/Default.aspx

TTS DataMaster - free download, 20 free uses

http://www.ttspowersystems.com/DataMaster.html

Cable:

http://www.akmcables.com/

Data interpretation:

http://www.injuneer.com/ScanMast.html
Injuneer is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
bfmv13trivium
General 1967-2002 F-Body Tech
9
01-14-2015 09:57 AM
1775.Z28
LT1 Based Engine Tech
7
01-11-2015 10:51 AM
Scottylt1
General 1967-2002 F-Body Tech
3
01-08-2015 02:48 PM
AlaskaZ28
LT1 Based Engine Tech
9
01-01-2015 12:30 PM
Scottylt1
Fuel and Ignition
1
12-04-2014 12:31 PM



Quick Reply: 94 z28 running rough when warmed up



All times are GMT -5. The time now is 06:33 AM.