DIY PROM Do It Yourself PROM chip burning help. No PROM begging. No PROMs for sale. No commercial exchange. Not a referral service.

Closed Loop issues

Old 08-19-2015, 05:08 PM
  #1  
Member
Thread Starter
 
beast94's Avatar
 
Join Date: Jun 2012
Posts: 104
Likes: 0
Received 0 Likes on 0 Posts
Car: 1994 Chevy K1500
Engine: 355ci, TBI with vortec heads
Transmission: 4L60E
Axle/Gears: 3.42
Closed Loop issues

Hello all,

I recently got my truck back running after moving an oxygen sensor bung to the collector, instead of the #6 primary tube; and also added a new bung on the opposite collector (SBC w/long tubes). I am running a WB in one and a dedicated NB in the other. Both are new sensors and appear to be working properly. However, I cannot get the EBL to transition into closed loop. This is a new issue and I am 99% sure I didn't have this issue before. Although, it has been a little over a month since I began the project, and I cannot remember if I made any changes right before beginning the project. I tried searching through my BIN and other Bins provided by DynamicEFI, and I cannot see anything unusual, but thats not saying that I didn't miss something. Any suggestions on what else to check would be appreciated. For WUD indicators, the WUD doesn't register any faults, and it signals that the engine is running, closed throttle, idle, and launch mode. I haven't seen any other indicators. Oh, Im running an EBL Flash with the TT-1 WB unit. And using TunerPRO.

Thanks.
Old 08-19-2015, 05:21 PM
  #2  
Member
Thread Starter
 
beast94's Avatar
 
Join Date: Jun 2012
Posts: 104
Likes: 0
Received 0 Likes on 0 Posts
Car: 1994 Chevy K1500
Engine: 355ci, TBI with vortec heads
Transmission: 4L60E
Axle/Gears: 3.42
Re: Closed Loop issues

I found a posting by RBob talking about the Closed loop: CTS Threshold and I checked it out. The value was at 47
Old 08-19-2015, 05:53 PM
  #3  
Junior Member
 
whatif3387's Avatar
 
Join Date: Jun 2013
Posts: 96
Likes: 0
Received 0 Likes on 0 Posts
Re: Closed Loop issues

Are you running a heated NB sensor?
Old 08-19-2015, 06:04 PM
  #4  
Member
Thread Starter
 
beast94's Avatar
 
Join Date: Jun 2012
Posts: 104
Likes: 0
Received 0 Likes on 0 Posts
Car: 1994 Chevy K1500
Engine: 355ci, TBI with vortec heads
Transmission: 4L60E
Axle/Gears: 3.42
Re: Closed Loop issues

Yes, standard Bosch 3 wire.

As an update, I was able to tune in Open Loop, but still no closed loop.
Old 08-20-2015, 06:44 AM
  #5  
Moderator

iTrader: (1)
 
RBob's Avatar
 
Join Date: Mar 2002
Location: Chasing Electrons
Posts: 18,399
Likes: 0
Received 215 Likes on 201 Posts
Car: check
Engine: check
Transmission: check
Re: Closed Loop issues

Double check that the forced open loop idle flag isn't set:

Option Word 1 - Bit 2 - OpIdl

More then likely it is due to inactivity on the O2 sensor. Just letting the engine warm up in idle isn't enough to get the O2 moving around for the ECM to know that it is ready for closed loop operation.

Sometimes all that is required is to blip the throttle some, if not then a short drive will do it.

Note about launch mode (LM), most of the included calibrations have the delta MAP to enter LM set too low. Bump this parameter up to 5 - 7 KPa to prevent the ECM from going in and out of LM:

LM - Delta MAP Threshold Enter

RBob.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Street Lethal
Power Adders
634
04-30-2019 12:14 PM
Eric2ndGen
Transmissions and Drivetrain
11
11-05-2015 01:51 PM
bamaboy0323
Tech / General Engine
25
09-03-2015 06:07 AM
CORV3TT3
DIY PROM
6
08-23-2015 11:26 AM
IROCThe5.7L
DIY PROM
1
08-10-2015 11:24 AM


Thread Tools
Search this Thread
Quick Reply: Closed Loop issues



All times are GMT -5. The time now is 12:54 PM.