DataMaster Log
Thread Starter
Racer
Joined: Jan 2004
Posts: 458
Likes: 1
From: NY
DataMaster Log
Hello! Im trying to tune a 95 lt1 Vette. The tune I have now is from pcmforless. I had reason to believe that it was rich do to the eye burnning exhaust and the black puff of smoke out the back when I get on it so I decided to get some tunning software.
Anyway, I dataloged my car at idle for about 15min. and was woundering if I could get someone to take a look at it with me? If I am looking at it correctly it is running rich. Here is what I have,
Fuel trim- cell 16 all the way threw the log.
LTerm- 108 to 122
STerm- 123 to 132
Knock counts- started right out at 1768 and stayed there.
O2mv- jumping from 102 to 850.
Spark advance- 26 to 30
Spark retard- 0.0 to 0.1
The spark retard didn't start til about 5min. into the log and it went from open to closed lope after the spark retard. Because of the LTerm counts being 108 to 122 I am thinking that it is burning rich. So am I even close and if so how can I change this?
Thanks, Ray
Anyway, I dataloged my car at idle for about 15min. and was woundering if I could get someone to take a look at it with me? If I am looking at it correctly it is running rich. Here is what I have,
Fuel trim- cell 16 all the way threw the log.
LTerm- 108 to 122
STerm- 123 to 132
Knock counts- started right out at 1768 and stayed there.
O2mv- jumping from 102 to 850.
Spark advance- 26 to 30
Spark retard- 0.0 to 0.1
The spark retard didn't start til about 5min. into the log and it went from open to closed lope after the spark retard. Because of the LTerm counts being 108 to 122 I am thinking that it is burning rich. So am I even close and if so how can I change this?
Thanks, Ray
Thread Starter
Racer
Joined: Jan 2004
Posts: 458
Likes: 1
From: NY
Originally Posted by STL94LT1
Can't you send your datalog to pcmperf, and they'll make the changes?
Or if you have Tunercat/LT1 edit, you can run the datalog through VEMaster and it will make the corrections.
Or if you have Tunercat/LT1 edit, you can run the datalog through VEMaster and it will make the corrections.
If Morley is reading this, I don't know what happen to you helping me out with my datalog but when you wouldn't return any of my e-mail I took it as though you didn't want to help.
Intermediate
Joined: Mar 2005
Posts: 41
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Same problem
Originally Posted by Morley
I sent you a PM about your log. You need to see if you are universally rich (in all fuel trim cells) or just a couple (or one) and go from there.
Last week I ran some Seafoam through without success. Any other ideas?
Last edited by larrynash; Mar 25, 2006 at 08:20 PM.
Drifting
Joined: Mar 2005
Posts: 1,923
Likes: 0
From: GA
Originally Posted by larrynash
I have the same year car and engine with the same problem. Today I recorded a datamaster file in acceleration. LT is very lean over 2000 Rpms, ST trim is ideal (over 900 mv on the O2 sensors and 149 LTerm counts). I'm changeing my fuel filter. Fuel pressure is fine at ideal but I will check under acceleration. What would cause LT to be out of wack?
Last week I ran some Seafoam through without success. Any other ideas?
Last week I ran some Seafoam through without success. Any other ideas?
With the int being in the 128 range that tells you that the ECM is able to compensate for the lean condition.
This is a stock engine? I would start looking for small vacuum leaks if it is stock...cracked plastic lines, PCV hose old and leaking at the connections, PCV valve leaking, etc.
Intermediate
Joined: Mar 2005
Posts: 41
Likes: 0
Lean Condition
Below 2000 Rpms and low airflow (30 gm/sec), everything is fine. LT and ST is around 127. Wouldn't a vacuum leak show itself most at low RPMs? If the problem is fixed, is there any way to clear the LT? How long until things look normal on its own if fixed?
Last edited by larrynash; Mar 25, 2006 at 09:04 PM.
Thread Starter
Racer
Joined: Jan 2004
Posts: 458
Likes: 1
From: NY
Originally Posted by Morley
I sent you a PM about your log. You need to see if you are universally rich (in all fuel trim cells) or just a couple (or one) and go from there.
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Intermediate
Joined: Mar 2005
Posts: 41
Likes: 0
Originally Posted by Morley
You have a mismatch there...lean BLM (149) and very rich O2 (900mv)
With the int being in the 128 range that tells you that the ECM is able to compensate for the lean condition.
This is a stock engine? I would start looking for small vacuum leaks if it is stock...cracked plastic lines, PCV hose old and leaking at the connections, PCV valve leaking, etc.
With the int being in the 128 range that tells you that the ECM is able to compensate for the lean condition.
This is a stock engine? I would start looking for small vacuum leaks if it is stock...cracked plastic lines, PCV hose old and leaking at the connections, PCV valve leaking, etc.
Drifting
Joined: Mar 2005
Posts: 1,923
Likes: 0
From: GA
Originally Posted by larrynash
If the problem is fixed, is there any way to clear the LT? How long until things look normal on its own if fixed?
Intermediate
Joined: Mar 2005
Posts: 41
Likes: 0
Long Term Fuel Trim
Originally Posted by Morley
"long term" is a relative term, in ECM speak it means a couple of seconds. The ECM is constantly learning and compensating for changes in the way the engine is running.
