? using EBL and VE - Third Generation F-Body Message Boards

slrvette · 07-14-2009, 09:18 AM

I have a question. I use the ebl/flash and LM-1 Wideband.
When I start the car cold is it normal for my Wideband to run on the leaner side? Typically its been running around 17 and has jumped as high as 20 for a split second then will drop down to about 15 and a little less.

While running down the road and if I punch the gas the AFR will drop to 13.1 or so then once you let off the gas pedal and as the car coasts those numbers again jump up as high as 17.

Just trying to figure out if these ranges are within reason. I'm running a track this Friday and don't want to blow up the motor or anything. The car seems to run great through all this, a lot of power.

thanks guys.

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Ronny · 07-14-2009, 11:14 AM

I will suggest your wideband is reporting the poor fuel distribution in the XRam on cold start. Remember it reads 02 content. Until that plem is heated it may not be accurate. Does it feel SOP Ok when you drive car cold?. My LM1 on cold start at idle in driveway shows about 12.5/1 this AM at 62 deg F.(holley project manifold). Once plenum sees heat I believe you should see results on WB.

When you let off gas manifold sees high vac low map and the wetting on manifold walls is sheared off. A lean condition is reported on WB. The wall wetting plays a greater role in A/F when manifold is not completly heated. When hot the fuel stays in suspension and does not stick to manifold. Less AE is then required. I will see an engine stall if I run on cold manifold then abruptly stop. Stall saver is there but not enough.

slrvette · 07-14-2009, 01:20 PM

Quote:

Originally Posted by Ronny

I will suggest your wideband is reporting the poor fuel distribution in the XRam on cold start. Remember it reads 02 content. Until that plem is heated it may not be accurate. Does it feel SOP Ok when you drive car cold?. My LM1 on cold start at idle in driveway shows about 12.5/1 this AM at 62 deg F.(holley project manifold). Once plenum sees heat I believe you should see results on WB.

When you let off gas manifold sees high vac low map and the wetting on manifold walls is sheared off. A lean condition is reported on WB. The wall wetting plays a greater role in A/F when manifold is not completly heated. When hot the fuel stays in suspension and does not stick to manifold. Less AE is then required. I will see an engine stall if I run on cold manifold then abruptly stop. Stall saver is there but not enough.

I never took into consideration of the xram. Our temp yesterday when I started it was 75 degrees. It was a cold start wb at 17.1, even after my temp was at 170 degrees only came down to 15. When I got in the car and drove normally it would run at 13-14.9. Brought it back and at idle once again wb 15-16. So it seems to run lean at idle.

On the tunerpro ve low table is there a calcuation or something I would use to adjust the AF at idle? I'd hate to change a number someplace and have it all screwed up.
thanks Ron

Drumer919 · 07-14-2009, 02:11 PM

I dont know anything about EBL but is there not an idle VE table?

Ronny · 07-14-2009, 03:02 PM

You can idle or off idle up so say 20 MPH(like me) in OL.

Or you can idle in CL.

In OL idle is off the rpm map coolant tables. If you are CL then you idle off VE tables with BLM feedback. If CL idle I would not be surprised to see 15.0-15.5/1. If fact if I allowed CL idle I would be right there. I think cam overlap may play a role for me. Plus not much velocity occurring at idle or distribution could be better.

Add the XRAM quotient and your lack of velocity at idle you may have some fueling issues occurring.

You can try to check the flag for lock OL idle and try that. And or enrichen the OL fuel tables along with.

Quote:On the tunerpro ve low table is there a calcuation or something I would use to adjust the AF at idle.

I dont believe so. In CL it will use that table/cell. for instance if you idle 35 MAP at 800 rpms it will use that cell. Fueling should be stoich or 14.7 on WB or 1.0 lambda with BLM control. Any VAC leaks or overlap and it will get funky. Same on OL idle. It just uses OL fuel tables and uses that cell it idles in.

Look at exhaust. Is it clean at idle?

Calibration of WB occasionally is a good idea.

slrvette · 07-14-2009, 06:42 PM

Quote:

Originally Posted by Ronny

I dont believe so. In CL it will use that table/cell. for instance if you idle 35 MAP at 800 rpms it will use that cell. Fueling should be stoich or 14.7 on WB or 1.0 lambda with BLM control. Any VAC leaks or overlap and it will get funky. Same on OL idle. It just uses OL fuel tables and uses that cell it idles in.

Thanks Ron I certainly am appreciating your help. I keep reading this part over and over.
So lets see if I get this right.
VE Table-Low Speed
The number across the top row is for MAP?
The first column is RPM

So if I go to the cell where 800 RPM meets35 MAP it reads 50.59. That is a voltage? And if it is then 50 would = 14.7? If thats true then my wideband would read about 14.9 if my rpm is at 800 and the MAP is at 35?
Take in account that there are some velocity issues with the X-ram then maybe that voltage should be set lower?

But before I do that I should actually go into my datalog and compare OL, while at idle RPM, and see where my MAP is, then go to my low speed table and see where the voltage is set at? Does this make sense to you?

If its voltage I'm looking at then above 50 is leaner and below is richer?

Ronny · 07-15-2009, 12:39 PM

50.59 is not voltage. It is just a value. Values run 1-99 in the table. higher # means more fuel. to add more fuel(to decrease BLM) by 10% 50.59 x 1.10 = 55.65.

Your WB in CL will always show stoich. It should regardless of fueling off VE. If the VE # is off it will correct to stoich with BLM/INT feedback. Getting the VE tables correct allows faster more efficient fuel corrections. Correct fuel with VE Learn in EBL.

VE at 50 vs 55 is adding less fuel.

If you idle OL then VE table is not used. Pretty sure on that. It uses OL tables.

Another way to control idle quality is to set IAC at zero steps at idle with commanded idle RPM set low. I idle 775 zero IAC and commanded to 600. Idle RPM is set by throttle stop screw. Removes IAC control at idle.

I would trust the WB readings off idle only. I think my idle reads on WB are affected by reversion within the intake and also from EXT outlet to sensor.

Keep the Q coming. Hope what I explain is 90% accurrate.
Cant say XRam is not good. It was not for me BUT I am cold weather climate. I have no cooant crossover in heads maybe you do. No way to correct a cold plenum that I know of. Just allow it to get heated.

slrvette · 07-15-2009, 05:19 PM

Oh I'm sure I can come up with a bunch of Q's for you...lol
I'm finding that each time you post I'm rereading more and more. I'm starting to kind of understand. I have had my SA tables adjusted and it really woke this car up to the point where you really need to hold on. Taking the car to the track Friday for a full day of test and tune and I don't want to blow anything up. I am going to also run the stock ecm just to make a comparison.
Funny thing is I'm changing this thing over this winter to HSR. Might just well since its new and didn't cost me a penny.

So my low speed and high speed tables are only used when moving and those numbers are value's only. The lower the number the less fuel is used and increase my BLM, then when more fuel is used it decreases my BLM. I'm sort of seeing how these tables intertwine with each other and play and important part.
Why can't they just make it simple and use a lambda value?..LOL

Ronny · 07-15-2009, 06:06 PM

Q:So my low speed and high speed tables are only used when moving and those numbers are value's only.
assumine you are idleing in OL. Otherwise VE is used for idle.

Q: The lower the number the less fuel is used and increase my BLM, then when more fuel is used it decreases my BLM. I'm sort of seeing how these tables intertwine with each other and play and important part.

not quite. The VE values should be sufficiently accurrate to create a neutral BLM(128). No larger nor small er are required. 02 feedback with a proper VE value should place BLM 128(+ or - 122-134). I seldom see 128 accross the board. Cool temps I see adding fuel 134. Hot temps 122. Just the feedback doing its job. I would think a ride at -20F with cold dense air will reflect higher BLMs. I never datalogged cooler than +40F.

Likewise high altitudes(less air) I believe will show significant BLM adjustments unless you are tuned for 11,000 ft use of vehicle.

I think the higher VE values(85-90) may appear at peak TQ of your engine