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

Need help with PE mode

Old Jul 26, 2010 | 07:11 AM
  #1  
86T/AWS6's Avatar
Thread Starter
Registered User
 
Joined: Apr 2001
Posts: 122
From: NEPA
Need help with PE mode

I originally posted this in the tuning section...I am copying it here hoping to get more traffic.

The car is a 95 M6 with intake, 503 cam, headers, gears etc.

This is the second PCM I tried, bought a used one on here and reflashed it.

I also tried a known stock 95 tune, along with other tunes made by myself and PCMforless.

The problem is when the car is in PE mode the ST BLMs are still working and pulling fuel, they jump around in the 130's. Data master confirms that the PCM is going into PE mode and the BLMs are being locked/ disabled. This seems to happen at about 3800 RPM. LT BLMs go to 128 and dont seem to change but the ST trims keep looking for 14.7 and bouncing in the mid to high 130's

I am altering the tune using tunercats and loading it using the EEL def file, which is supposed to lock the BLMs

What sensors does the PCM look at while in PE mode? Could one of them be causing this? It seems that when I go WOT it initially locks the BLMs at 128, then within a few seconds the ST trims start jumping up and causing the O2s to read in the .050 to .600mv range.

I need some of the experts here, I am lost.
Old Jul 26, 2010 | 11:15 AM
  #2  
Injuneer's Avatar
Administrator
 
Joined: Nov 1998
Posts: 71,098
From: Hell was full so they sent me to NJ
Your premise appears to be that the ST's are pulling fuel. If they are above 128, they are adding fuel.

Have you checked the TP% vs. RPM table for PE engagement? Seems like it may be slipping into and out of PE mode, although the PE mode flag in DataMaster is reliable.

Have you verified that the PCM is calculating a PE mode target A/F ratio in the range of 12.8-13.2:1?
Old Jul 26, 2010 | 09:49 PM
  #3  
rskrause's Avatar
Moderator
 
Joined: Dec 1969
Posts: 10,745
From: Buffalo, New York
What problem are you trying to solve?

Rich
Old Jul 27, 2010 | 07:17 AM
  #4  
86T/AWS6's Avatar
Thread Starter
Registered User
 
Joined: Apr 2001
Posts: 122
From: NEPA
I m trying to solve/ figure out why the BLMs are not locking at 128. I tried BLM locker and I am now using the EEL file from TC which is supposed to lock the BLMs and neither work. I can not get a consistant WOT O2 reading and its showing lean.
Old Jul 27, 2010 | 08:44 AM
  #5  
rskrause's Avatar
Moderator
 
Joined: Dec 1969
Posts: 10,745
From: Buffalo, New York
Do you have wide band you can borrow? Is it really lean is what I am asking. How is it running? If you didn't see those "lean" readings would it be a problem?

Rich
Old Jul 27, 2010 | 09:00 AM
  #6  
86T/AWS6's Avatar
Thread Starter
Registered User
 
Joined: Apr 2001
Posts: 122
From: NEPA
Well idle and part throttle response is crisp and snappy. When I got to WOT around 3000rpm it pulls hard and feels strong, however, it feels kind of flat on the top end, like 5000+. Feels like it did with the stock cam.

The MAIN thing that caught my attention is that recently I got to the track for the first time since puttin in the XE 224/230 cam in 2005 and I only gained 1mph and .05 et. It felt flat on top with the RPMs just hanging around 5800-6000 for the last bit of the track.

For example with the stock cam and all other mods the same, my best time was 13.17@107.5 on a 2.07 short.

2 months ago with the 224/230 my best was a 13.10@108.3 on a 2.05 short.

When the cam was first installed the PCM was locking and I was able to tune the fuel to a steady .850+ mv on the O2's. I havent changed or modified anything since then. When I saw my results at the track I logged it and noticed the BLMs playing this game, reflashed a bunch trying different tunes, and then bought another PCM...all outcomes are the same
Old Jul 27, 2010 | 09:11 AM
  #7  
Injuneer's Avatar
Administrator
 
Joined: Nov 1998
Posts: 71,098
From: Hell was full so they sent me to NJ
Can you put the DataMaster log somewhere that we can download it and take a look at it?
Old Jul 29, 2010 | 12:56 PM
  #8  
86T/AWS6's Avatar
Thread Starter
Registered User
 
Joined: Apr 2001
Posts: 122
From: NEPA
Sorry fred I dont really have anywhere to host the logs, I could email them to whoever wants them though. I actually would really appreciate someone who really knows tuning to take a look at them and the corresponding program.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
drt
LS1 Based Engine Tech
6
Sep 27, 2015 04:39 PM
autoxr166
General 1967-2002 F-Body Tech
0
Sep 25, 2015 04:21 PM
MDZ28
Computer Diagnostics and Tuning
11
Sep 24, 2015 09:15 AM
4586
LT1 Based Engine Tech
1
Aug 24, 2015 11:04 PM
PFYC
Supporting Vendor Group Purchases and Sales
0
Aug 7, 2015 08:52 AM


Thread Tools
Search this Thread

All times are GMT -5. The time now is 06:41 PM.