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Been tweaking, testing and tweaking my VE tables today and believe I'm really close except for one thing I cant seem to alter. After a drive and I sit in driveway with truck idling the BLMs drop all the way down to 106-108 or so in the 600-800rpm and 30-35Map cells. Everything else is getting real close, but these never seem to change. Is there another parameter I should be adjusting as well?
I'll try to get a good data log tomorrow but for now here are some screen shots.
Look at your data and make sure it is showing Idle when at Idle, and Off Idle when Off Idle. Just wondering if you have an issue with the conversion since your doing well elsewhere?
Have to seperate data as well I think you know? So your adjusting Off Idle fuel with Off Idle BLM data? For the Idle fuel table I usually make it identical to Off Idle, except for the 6-9 cells around where the engine idles.
In the Off Idle table I like a smooth transition as shown in your 3D graph picture. For the Idle table it's OK to have say 6-9 cells that are flat with the same number to get idle dialed in.
Remember the cell you are idling in is not the exact number the PCM is useing for fuel! It is interpolated from that cell and all surrounding cells.
The '427 PCM has two fuel tables and two spark tables (near idle / off idle). I would check the parameters ( %TPS usually 2.7 % & MPH usually 3 MPH) when the '427 is set to be in near idle. TunerPro RT is an excellent program, but the '427 near idle / off idle BLM averages are not 100% accurate. I use Microsoft Excel to accurately separate near idle / off idle data.
dave w
When this happens the "Idle Spark" is enabled.Quote:
Originally Posted by EagleMark
I spent most of the afternoon adjusting the Off Idle VE first Using the Off Idle BLM data and got it real close. I moved to the Near Idle VE and actually copied the 1600,1200, 800 and 400 rows out of my Off Idle table. Then I adjusted the 1800,1400,1000 rows manually to fix the map. I then lowered the VE in the idle cells I was having trouble with and manually smoothed the table to what you see now. However it didnt have much if any affect.Quote:
Originally Posted by EagleMark
OK I was moving that direction but wasnt sure.Quote:
Originally Posted by EagleMark
I remember you mentioning that in another thread and have been applying that rule best I can.Quote:
Originally Posted by EagleMark
I hadn't given the Idle Spark table much thought at all, that could be what I'm missing as my Main Spark Table(open throttle) has been modified to a Vortec truck Map. Should the Open Throttle and Closed Throttle spark tables mimic each other like the fuel maps until you get into the idle cells as well?Quote:
Originally Posted by dave w
I would try having both Open Throttle / Closed Throttle Timing tables nearly identical. Keep the near idle timing table near stock settings for engine start up ( 400 RPM's ~ 600 RPM's for Kpa's above 75). The start up timing is usually ZERO or negative a few degrees.Quote:
Originally Posted by brian617
dave w
I will give that a shot. I also checked and verified that my Maximum TPS% and Maximum MPH Spark Idle parameters are at 2.3% and 4mph.Quote:
Originally Posted by dave w
That's probably an issue!Quote:
Originally Posted by brian617
Your cam does not look to big but adding some spark to idle helps. So yes, mimic but more spark in idle table for idle and then feel it out but less idle spark in off idle spark table.
Ok, I copy and pasted Open Throttle spark table into Closed Throttle table and then raised spark in the cells I was having trouble with. Then I pulled more and more VE out until my BLMs got in the 124 range and figured that was close enough for now. Now I have developed an open loop idle surge and an off idle hesitation. Best I can figure the hesitation is that the auto .BIN needs more AE as I have a manual trans.
How much AE should I add and where for starters?
What can I do for the open loop lean surge?
I would try adding 10% to both AE MAP and AE TPS, and see how that works.Quote:
Originally Posted by brian617
dave w
A Wide Band O2 is an excellent tool for figuring out AE and open loop lean surge.
I have a Wide Band in the truck, just not sure what parameter to correct for open loop.Quote:
Originally Posted by dave w
I'll bump up the AE 10% and see what gives. I tried messing with it the other day and got carried away then had to revert it back to stock settings.
What does your "Open Loop AFR vs. Temperature vs. Vacuum" table look like? Depending on how that is set up... you may have pushed the six flat cells for idle to far?Quote:
Originally Posted by brian617
For the AE do as Dave said. The reason you found this issue now is your not running pig rich and it needs AE to compensate, before it was so rich it had AE already pre-installed! :innocent2:
Another way to get an idea of how much AE your going to need to compensate for an Auto bin in a Manual trans is open a $0E manual bin. I don't have these $0D memorized like $42 but mans there's a lot more AE in a manual bin.
Quote:
Originally Posted by EagleMark
That's what I was thinking too.Quote:
Originally Posted by EagleMark
I'll dig through the .BINs and see what I can find. I assume that there is a different AE curve for a manual, not just a percentage increase. Can you think of an $0E manual off hand?Quote:
Originally Posted by EagleMark
Thanks for the help Dave and Mark. Much appreciated!
Man it's hard to find manual bins for the E trans PCMs?
Change your "Open Loop AFR vs. Temperature vs. Vacuum" to 14.0 as the highest and that should cure your lean surge in OL. Everything else lower then 14.0 is a good thing for when cold.
Dave, the 10% AE in MAP and TPS sure did the trick for the throttle off idle hesitation. Now the only issue I'm having is a closed throttle in gear at speed to open throttle jerk. Would that be more AE MAP or more AE TPS related? I'm guessing MAP?
Mark, I still have the lean surge in open loop after start up even after adjusting the table to 14.0:1 in any cell 14 or higher with no success. Then I remapped the table even richer and only gained a rich condition on a dead cold engine. Which then after some warm up, still open loop, turn back into a lean surge. When I does enter closed loop the idle settles but BLM is 140 or higher around 150 degrees F coolant temp. The BLM will return to 128 or close after engine is fully warm at 190-200 degrees but it takes driving the truck to get that tempature.
I'm thinking I should revert the Open Loop AFR table to stock, then possible fool with my timing table some more. Maybe I just have too much advance and thats causing the surge? Or maybe there is a coolant temp bias I need to look at?
I am trying to help a buddy in a stock 88 GMc truck deal with the 108 blm issue as well. all sensors are new Ac Delco, and engine is mechanically sound. Seems to be a big problem with TBI.
Expalin more on what throttle jerk is?Quote:
Originally Posted by brian617
10% is not much, for instance Vortec heads swap needs like 200%!
To help you decide what it needs you need to understand the difference of TPS AE and MAP AE. AE-TPS is for when the throttle blade moves, that's it, very short like millaseconds. AE-MAP finishes off the transition and is much longer, like 2-3 seconds.
Yes if the change did not help always revert back.Quote:
Originally Posted by brian617
Did we ever see a data log after warmed up and driven, then idle in drive and park for a minute? What I'm getting at is IAC count to be as low as possible.
It could be a spark timing issue! You have increased spark correct? Sometimes when spark advance is more on the performance side it has enough spark for cold conditions, then you have to much Cold Spark added on top of that!
Do a data log of the cold start issue and post it with your current bin and we can take a look at how much spark is going on through this issue.
Only when it's rich! The 108 is bottomed out so it can't do anymore, this is always an issue at idle with aftermarket cams. But could be to much fuel pressure? Or a vacuum leak! EGR stuck slightly open? IAC count to high... meaning not enough air mixing with fuel over the throttle blades and it drips causing a wet (wetter then normal) intake.Quote:
Originally Posted by jameslleary
Where you been?
First log is cold start albeit 70* ambient temps today with plenty of humidity. Note that when I spent the day tuning my BLMs it was a cooler 55* day with alot less humidity. May need to remork fuel map again for some balance.
Second log is a short drive with engine already at max coolant temp and then some idle time.
I reverted my Open Loop AFR table back to stock, and took some timing out of the idle cells before I logged, along with a little more AE which seemed to help the closed throttle to open throttle at speed jerk.
The warm log idle shows a low IAC count 13 which is good. I don't think you could do better.
One thing you have done and I don't see a need for it with this cam is set base timing to 4.2* This also advances injector timing. If you don't have a reason or want to try, I would go back to 0* base timing. Also change it in bin.
Since your learning great and still eager! :rockon: I'm going to do this a little differant. I made some changes to your bin, open it and use the compare feature and load the old bin. Then go to tools and Difference tool and find what I did and try to explain why I did it! You'll also have to check and see if it helped... I'm not sure it is the cause but will soon find out! :thumbsup:
You got headers on this? Stock exhaust?
I can certainly try it, only reason I have it set like that is the cam is ground 4* advanced and I thought it would work well together.Quote:
Originally Posted by EagleMark
Much appreciated, will give a good look over!Quote:
Originally Posted by EagleMark
I have a very unique set up for exhaust. Stock manifolds mated to a 96-98 3/4 ton factory dual 2-3/4'' no cats into 02 model 3/4 ton dual inlet dual outlet muffler then it Y's into a 3-1/2'' single out. I think it moves air well without any noise.Quote:
Originally Posted by EagleMark
How far from stock location did the O2 sensors move?
The stock o2 for my truck was in the left manifold just before the collector. Now I have a heated o2 in the right side pipe just 2'' down from the collector and my wideband in the left pipe same location. These are the stock locations for the upstream o2's on a 96-97 Vortec truck.
Here is a picture off Google image.
First, I see you smoothed out the Idle VE mapQuote:
Originally Posted by EagleMark
Second, Looks like you reduced the Startup Spark vs Temperature meaning less cold advance.
Third, Idle Overspeed Retard/Advance vs RPM Error were reduced to calm the swinging advance at idle.
Forth, and i'm not sure why you did this, but you zero'd out negative advance in the 104* Celsius (219*F) row in the CTS Spark Advance Compensation vs Vacuum vs Temperature.
This mornings cold start still surging but not the o2 or wideband readings of lean like yesterday. The other thing I think is crazy with my current Idle VE map, the BLM at 158* F is 136 and thats shortly after closed loop. Then when I drive to work with the coolant temp around 194* F the BLM is back to 124.
Is there a specific table for that bias? And is that what I need to work on first?
Your good! :thumbsup:
When I was using data tracing I saw during the lean surge it was jumping from the flatter idle area up a big slope. So smoothing it out should be a help. Still may need work there in tuning the VE.Quote:
Originally Posted by brian617
Yes because you've added much swpark to stock table and with this adder could be to much, causing mis fire, surge etc...Quote:
Originally Posted by brian617
Right! Idle is controlled by spark but sometimes it can be to much and constantly over-undershoot. Not so much stock motor but cams and such do cause issues.Quote:
Originally Posted by brian617
Data tracing found some missing spark advance and it was bumping into row before this so I zeroed it out.Quote:
Originally Posted by brian617
That was before I noticed the Base setting timing bias which explained the missing timing!
Can you explain this more, I did notice the increase of advance at cruise and light throttle on the way to work this morning. It was an improvement for sure.Quote:
Originally Posted by EagleMark
My burb is dead in the water up in humboldt county. trans seal failed, and roasted my barely 2 year old trans rebuild. wifey has had it, and wont trust it, even with a new trans.Quote:
Originally Posted by EagleMark
Depending on engine temp the "CTS Spark Advance Compensation vs. Vacuum vs. Temperature" can add or subtract spark. Using the Data Trace feature during playback of a log you can see exactly where you are. In this case the line above where timing starts to pull from heat, but remember the cells are interpolated so it was getting some, not all.Quote:
Originally Posted by brian617
I saw in your spark advance table around 21*, but only 15-16 showing in data lists. But now I believe this is from the base timing at distributor set to 4.x, your distributor set to 4.x so it's there. But my adx file did not have the extra timing built into the Conversion, it is set to 0*.
Ok the light bulb came on finally :happy: I plan on setting it back to zero* next chance I get so I can better understand whats going on. A lot to digest so it would just be better if i'm seeing actual data right now.Quote:
Originally Posted by EagleMark
Thanks Mark
Is there anyway to edit (reverse) the rows or columns in TP so the 2D and 3D maps match? They appear mirrored and for a guy like me that is more visual, it really bugs me they dont jive.
Found it!Quote:
Originally Posted by brian617
Tools-Preferences-General tab-Table editor options
:thumbsup:
I knew how to do that... but can't visualize why you needed it?
OCD, things must match :laugh:
Man that would have helped years ago! I guess I re-orginised my OCD because it's OK now without the change...