Refining a 6e stock tune
05-02-2014, 09:09 PM
#1
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Refining a 6e stock tune
I'm going to borrow by brothers tuner-pro moates setup to do some data logging on my '89 (all original 16K miles). Just looking for some suggestions to refine the factory tune assuming there are no major knock counts. Nothing major, not looking to log with a wideband (although I'd love to) or mess with timing or PE. Car is fully tuned i.e. base idle adjusted, TPS @ .54v, IAC reset, new O2 sensor, injectors checked, new Delco fuel pump, plugs, no vacuum leaks etc. Car runs great.
Ideas
1. Lower fan turn on temp 10 degrees to 215 or so
2. Remove the eight 0's cold start tables to improve cold start up a bit
3. Record BLM's and adjust via injector constant to 128 +/-
4. Might refine areas of the MAF tables if this is out of wack
Any other ideas while I have the opportunity to do this or am I off track? Open to suggestions!
James
Ideas
1. Lower fan turn on temp 10 degrees to 215 or so
2. Remove the eight 0's cold start tables to improve cold start up a bit
3. Record BLM's and adjust via injector constant to 128 +/-
4. Might refine areas of the MAF tables if this is out of wack
Any other ideas while I have the opportunity to do this or am I off track? Open to suggestions!
James
05-02-2014, 11:21 PM
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First datalog. That will tell you what you are dealing with. Stock MAF and cold start are very good and I doubt you will need to tweak them. Fan is a good place to start. There are a few fan on/off switches. AC on and AC off. Injector constant should be close but you can tweak it and datalog to see results. The more you learn the more you will find to change. Just start out slow . Next thing you know it will be cam and heads and maaajor tuning. 
05-25-2014, 08:25 AM
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Just an update: Hope this might help the first timer diving into their maf 6e tune on a stock engine.
Just some questions:
1. Can my idle be smoother?
2. Why does my '89 take so long to start up?
I spent the better part of 2 weeks data-logging and finding small issues with the factory ARAR bin in relation to my specific car (with 16,400 miles) and the conditions down here in So. Florida. I've replaced the injectors with the later updated GM-Delphi's (same part number as stock multitechs), new Delco fuel pump, new regulator diaphragm, rail O-rings, New Delco EGR valve, Cleaned IAC/Throttle body, and zero vacuum leaks.
Keep in mind, this is a 100 percent stock '89 L98 700R4 with 2.59's in the rear. I switched over to Tuner Pro RT and used the data tracing to dive into parts of the map via data tracing. Fuel Pressure is 39, 44 unplugged from vacuum. 18" Vacuum at idle, needle steady.
I was getting high knock counts under certain circumstances. Example: WOT tip in while downshifting down to 1st gear.
1. Factory closed loop tune was a bit biased lean in some sections of the map. I lowered the injector constant slightly to compensate since I did not install the adjustable fuel regulator. Worked great. BLM's are now 128 and biased slightly rich.
2. Lean WOT tip in at speed. At 30-35 MPH (BLM was 135) and gunning it, I'd get a lean spike that shot the knock counts through the ceiling. We are talking about a fraction of a second here. Getting the BLM's (as above) set properly and very slight adjusting of the acceleration enrichment tables and AE decay cured this.
3. Added slight fuel to PE vs Temp. to improve slight lean condition at WOT. I'm running a wideband so I 'plug chopped' at WOT to look for color. Nice cocoa color on the plugs.
Improvements ARAR map.
1. Copied the 575 rpm idle speed settings from the ARAP map. My car certainly likes 575 (vs 550) idle speed much better. Also adjusted the MV of the O2 sensor bias at idle up a few MV to make idle a bit richer. This was a huge improvement.
2. Fixed up the starting issue by adding pulse where there were none (.2,.2,.5,.5,.2,.2....)
3. Adjusted Fans to 212 on-205 off which works well here in Florida with a 180 stat. Running temperatures has lowered considerably.
Otherwise, I thought my car ran pretty good but it now runs really, really good. Smoother across the board, cooler in town and on the highway, starts instantly and I finally have a very smooth closed loop idle. Knock counts on a hot day at temperature are down to a handful under all conditions from 80-125. A fun project.
Some non scientific observations:
O2 sensors. My factory 25 year old Delco O2 sensor seems like a better match then the new Denso O2 I installed in the car a few months ago. Not sure if this is the design or calibration but I'm sticking with the Delco.
Fuel Canister purge can cause a slight lean condition under certain circumstances. If your BLM's are in line, this won't cause much an issue but if the can is purging, BLM's are raised a bit and you hit WOT, you might see knock counts.
Not an expert by any means, just passing along some information while it is still fresh.
James
Just some questions:
1. Can my idle be smoother?
2. Why does my '89 take so long to start up?
I spent the better part of 2 weeks data-logging and finding small issues with the factory ARAR bin in relation to my specific car (with 16,400 miles) and the conditions down here in So. Florida. I've replaced the injectors with the later updated GM-Delphi's (same part number as stock multitechs), new Delco fuel pump, new regulator diaphragm, rail O-rings, New Delco EGR valve, Cleaned IAC/Throttle body, and zero vacuum leaks.
Keep in mind, this is a 100 percent stock '89 L98 700R4 with 2.59's in the rear. I switched over to Tuner Pro RT and used the data tracing to dive into parts of the map via data tracing. Fuel Pressure is 39, 44 unplugged from vacuum. 18" Vacuum at idle, needle steady.
I was getting high knock counts under certain circumstances. Example: WOT tip in while downshifting down to 1st gear.
1. Factory closed loop tune was a bit biased lean in some sections of the map. I lowered the injector constant slightly to compensate since I did not install the adjustable fuel regulator. Worked great. BLM's are now 128 and biased slightly rich.
2. Lean WOT tip in at speed. At 30-35 MPH (BLM was 135) and gunning it, I'd get a lean spike that shot the knock counts through the ceiling. We are talking about a fraction of a second here. Getting the BLM's (as above) set properly and very slight adjusting of the acceleration enrichment tables and AE decay cured this.
3. Added slight fuel to PE vs Temp. to improve slight lean condition at WOT. I'm running a wideband so I 'plug chopped' at WOT to look for color. Nice cocoa color on the plugs.
Improvements ARAR map.
1. Copied the 575 rpm idle speed settings from the ARAP map. My car certainly likes 575 (vs 550) idle speed much better. Also adjusted the MV of the O2 sensor bias at idle up a few MV to make idle a bit richer. This was a huge improvement.
2. Fixed up the starting issue by adding pulse where there were none (.2,.2,.5,.5,.2,.2....)
3. Adjusted Fans to 212 on-205 off which works well here in Florida with a 180 stat. Running temperatures has lowered considerably.
Otherwise, I thought my car ran pretty good but it now runs really, really good. Smoother across the board, cooler in town and on the highway, starts instantly and I finally have a very smooth closed loop idle. Knock counts on a hot day at temperature are down to a handful under all conditions from 80-125. A fun project.
Some non scientific observations:
O2 sensors. My factory 25 year old Delco O2 sensor seems like a better match then the new Denso O2 I installed in the car a few months ago. Not sure if this is the design or calibration but I'm sticking with the Delco.
Fuel Canister purge can cause a slight lean condition under certain circumstances. If your BLM's are in line, this won't cause much an issue but if the can is purging, BLM's are raised a bit and you hit WOT, you might see knock counts.
Not an expert by any means, just passing along some information while it is still fresh.
James
