LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Fuel Trim Problem

Thread Tools
 
Search this Thread
 
Old 05-01-2007 | 01:47 PM
  #1  
Stroker396@APF's Avatar
Thread Starter
FormerVendor
iTrader: (18)
 
Joined: Jan 2007
Posts: 587
Likes: 0
From: Lost Angels, CA
Default Fuel Trim Problem

I have been trying to diagnose and solve this problem for a while.

The car thinks Bank 2 is lean and is dumping fuel on it. Causing 10MPG!

I have tried to seal up any intake or exhaust leak, but the O2 still does not osolate and it is new.

here is the latest readings from the car.

Anyone have any idea what could be causing this situation?



Old 05-01-2007 | 08:30 PM
  #2  
MEAN LT1's Avatar
TECH Fanatic
iTrader: (2)
 
Joined: Jan 2003
Posts: 1,143
Likes: 0
From: jacksonville,FL
Default

Image shack isnt working right now but what millivolts is the passenger side o2 showing. Is it going into closed loop, I have a feeling you might have a failed o2 sensor.
Old 05-01-2007 | 08:50 PM
  #3  
Stroker396@APF's Avatar
Thread Starter
FormerVendor
iTrader: (18)
 
Joined: Jan 2007
Posts: 587
Likes: 0
From: Lost Angels, CA
Default

seems to be working now, but the reading is 0.445

This is the second O2 sensor, brand new.
Old 05-01-2007 | 09:16 PM
  #4  
GMRL's Avatar
TECH Regular
15 Year Member
 
Joined: Sep 2005
Posts: 478
Likes: 42
From: TX
Default

Check the injector O-rings for vacuum leaks. Same thing happen to me once, spray some water into the bungs, that makes it easy to detect leaks. Also check for leaks where the intake meets the head. Also the wiring harness for that o2 sensor.
Old 05-01-2007 | 09:23 PM
  #5  
Stroker396@APF's Avatar
Thread Starter
FormerVendor
iTrader: (18)
 
Joined: Jan 2007
Posts: 587
Likes: 0
From: Lost Angels, CA
Default

I should mention that I have been working on this for a while
So far here are the things I have done/checked

1. Injector o rings - sprayed ether to see if engine reves up - nada
2. replaced intake and gaskets - with ported for 58mm tb
3. replaced exhaust gasket and rtv sealed it to header
4. block off plates
5. RTV collector to Y pipe
6. Tighened #8 plug (it was loose) and it is the black one. #4 was gray
7. replaced O2 sensor
8. I am sure there is more I am forgetting.
9. Fixed vacuum leak from Pass firewall (to vents)

I have been told to triple check the wiring. It is not near the headers I could try swaping the bank one good O2 over but likely with the same results.
Old 05-02-2007 | 11:57 AM
  #6  
flame's Avatar
TECH Fanatic

iTrader: (13)
 
Joined: Oct 2004
Posts: 1,169
Likes: 2
From: Waterloo, Ontario
Default

Is the check engine light on? Any codes? It appears that the bank 2 sensor is flat lined at .445 indicating that the circuit is open. Likely a broken, corroded, melted wire in the harness.
Old 05-02-2007 | 12:46 PM
  #7  
Stroker396@APF's Avatar
Thread Starter
FormerVendor
iTrader: (18)
 
Joined: Jan 2007
Posts: 587
Likes: 0
From: Lost Angels, CA
Default

No Codes. I will take a look at the wiring today. I hope that is all it is and that I can find it.



Quick Reply: Fuel Trim Problem



All times are GMT -5. The time now is 11:30 PM.