I just installed a zeitronix Lambda meter and data logger in my car. It seems to be a really nice piece, and it uses the less expensive bosch lsu4 sensor (so I plan on leaving it installed).

I want to give another plug to Ion at Madz, because the mail order tune he did for me is very good. The AFR at WOT ranges from 13.1 (at 3000 rpm) to 12.8 or 12.9 (at 6400 rpm). I am very happy with those numbers.

My question is about what happens right when I step on the gas. As soon as I go WOT, there is a short lean spike(~15.5-17.0) before the afr levels out. The car doesn't hesitate, but I would like to fix it if I can. Or maybe it is nothing to worry about, has anyone else noticed their car doing this?

I have tunercat, but I haven't seen a table for this.

Thanks
Dustin

 

That can be controlled by the AE functions.

Usually what your describing causes knock between gears and stuff like that. It isn't very good to have. If you set them up to flash down into the 11's the car will feel better.

 

What are AE functions?

 

Acceleration Enrichment It kinda simulates what a acceleration pump or like a squirter does on a carb. When you whack the throttle, even with EFI there is a lot of transitions going on and AE will add some extra fuel to eliminate the lean spike.

Alvin,
I wasn't aware that anyone has found or added the AE vs delta TPS or AE vs delta MAP to either TC or LT1 Edit. Do you know where it is? Inquiring minds would like to know

Steve

 

I had heard of people making changes to "pump shot" on older fuel injection setups, but I haven't seen a way to do it in tunercat. Is there a table I'm overlooking? I will go take another look at it.

Thanks for the help
Dustin

 

Thats nothing to worry about, I believe FAST has this as well but you can control it I think the table there is called Throttle opening Anticipate fuel enrichment or something rather along those lines, I know the stock PCM has it but noone found it yet.

Point is that the lean spike will most likely not hurt you at all because when you get that it is a momentary spike, at that point you haven't created any cylinder pressure yet really and plus something of that calibor isn't enough to create any heat in your combustion chamber to cause knock/detonation.

I'm sure if you email TC they'll find it for ya, they're great people

Also, if you are really worried leave your Burst knock on because with burst knock you get a momentary reduction of timing when your maf readings change sharply which is what happens at that point when you give it throttle real fast.

 

I heard the MAF covers a lot of the needed AE. But, that doesn't explain why the car runs so well in SD mode. So, obviously there is a yet-undiscovered AE vs TPS table.

What have people been doing to bandaid this if there's no AE table though?

 

Alvin,

Your so quiet on this thread. Do you know something more about AE on MAF LT1 cars??????????