CammedEvo

iTrader: (5)

Hi Guys,

I've got a condition with my car that I have an idea how to solve but would like some advice before I go tweaking with tables I've not touched before.

Issue: Rich condition when lifting to light throttle after mid.
Load: 9kpa
RPM: Any

Setup Details:
10.4:1 2.3L
FIC2150's
E85
o2 feedback not used
96531706

Notes:
-I want to correct this without altering injector scaling.
-I do not think adjusting the load will fix this issue as I've gotten it down to 9kpa already. (But I'm open to suggestions from other tuners)
-If I completely lift on the throttle its not an issue. It's only when I lift and remain at ~20% throttle.

My Thoughts:
Stock Decel subtraction needs to be altered since I've significantly altered my load curve from when I used a MAF. My load numbers were much higher on the maf as I've adopted the JB 25psi = 250load methodology for standardization.

Has anyone had any luck fixing a condition like this with the decel subtraction tables? Could you post an example?

Thanks for the help guys.

mrfred

iTrader: (50)

A few questions:

- To what degree do you mean that O2 feedback is not used? Do you have a front O2 sensor installed? Is the STFT not active? Do you have something turned off in the periphery bits?

- Does this happen when you're cruising down the road off-boost and you partially lift throttle? How long does the rich condition last? Do you have a log (that includes TPS, AFR, RPM, load, IPW)?

CammedEvo

iTrader: (5)

To what degree do you mean that O2 feedback is not used?
It is not used. Ever

Do you have a front O2 sensor installed?
I do, it's dead from leaded gas. Died many years ago.

Is the STFT not active?
It is not.

Do you have something turned off in the periphery bits?
Yes, false for Periphery0 (FAA) bit.4. Other options in here are false but I suspect this is the one you were inquiring about.

Does this happen when you're cruising down the road off-boost and you partially lift throttle?
Yes, thats exactly when it happens.

How long does the rich condition last?
From normal logs maybe half a second. Usually stopped because I hit -12.5 or below and injectors are shut off or I get back on throttle. I'll try tonight to see how long I can make it last.

Do you have a log (that includes TPS, AFR, RPM, load, IPW)?



In the above screen shot you'll a bit of what I'm talking about. What I'm wanting to control is the negative throttle aspect of Transient Fueling. I suspect that Decel subtraction is what controls this.

It appears that more fuel(in relation to positive throttle) is being left behind during negative throttle then any of my previous injectors. Perhaps its the position or spray pattern of the 2150s?

I understand that this issue is somewhat trivial but I would like to understand how to control it better.

chamelieon

iTrader: (21)

had this issue few days ago with a customers car, might not be exact but somehow his TPS was 18% at idle.. so anytime during a decel it would keep the injectors open and car would decel on 12AFRs. his TB was never touched or modded, but i loosened the TPS and adjusted it to 12.9% and Bam injector cuts out on decel and goes full lean! so I see you have 15% ..that might be enought to do it..

CammedEvo

iTrader: (5)

My injectors cut off on complete throttle lift. ~-12.5 vacuum.

I can have them cut off earlier thats no problem. Let's re-examine the log snippet I posted earlier.



See the focus area? I lift ever so lightly ( you can tell by the MAP change ) and it richens up. IPW stays the same as it was during positive throttle but AFR is almost a full point richer.

This IPW is fine at this load x rpm during positive throttle but it's not during negative throttle. Am I making sense?