I think I stumbled into (pun intended) to my stumbling/surging problem. I went back over all my constants comparing them to the Aclp bin which is a 454 bin. which I am using for any thing that has to do with the injectors or bpw and the filter constants from a 4.3 bin. I found out that I hadn't changed the following

Minimum BPW Hyst Value
my bin=701.5 454 bin=1692.75

Minimum BPW
my bin=503.25 454bin=1403

I did change the Min Asynch BPW and the Max Asynch BPW to the 454 settings I did notice that the Min Asynch BPW was 1403 which corresponds with the Min BPW.

I changed these settings to the 454 settings and it quit surging and all of my blm's shot up to like 160-170 where previously they were +-5 from 128. The car drives much better now. Just have to get the blm's back down out of the stratosphere.
My second question has to do with the egr off BPW constant. I did the math and I should need a BPW of 94-100 depending on my FP. Right now i'm at 115 and I still need to go higher in order to get my blms to a point where I'm not maxing out my VE curves. Is this ok or am I feeding the ecm a big lie thats gonna bite me later? Also what exactly does the injector bias constant do? Would this be the place to add the extra fuel without getting my BPW const too far off track?

Here's my setup
454 tb with unknown injectors either 80's or 90's
fuel pressure is 16 psi
747 ecm
the rest is in the sig

 

Fudging by 10% or so on the BPC with some applications is about normal.
Dunno how you came up with a particular BPC without knowing which injectors your have.

My .bin has a BPC of 139, for a 91, 454.

With the 60PPH injector setup I'm running in the Sy cal, I'm playing with values from 80-120. It seems to all work out given proper tuning.

Yes, you also need to have the min/max pulse widths dialed in. Mine was 1704 where you show 1692.

Then when you have everything final and sorted out you get to dither with the VEII table.
An ecm bench saves lots of wear and tear for that.

 

Refer to the code snap below. The first two (LD2D6, LD2D8) are used to decide when it is time to switch in and out of async fuel mode. While in sync mode (the typical mode) once the PW drops below 504 usec the ECM will enter async fueling mode.

Once the sync PW goes above 702usec the ECM will return to sync fueling mode.

One key here is that the ECM always calulates the sync PW. The async PW is mathematically derived from the sync PW. So it always knows what the sync PW is for switching in & out of async mode.

The injector bias value (LD2DA) is added to the PW. It is an adder to whatever PW the ECM calculated. I always figured that it was to compensate for the injector opening time. It is used for both sync & async injector firings.

The last two (LD2DC, LD2DE) are used to control the minimum and maximum PW of an async injector firing. The maximum allowed open time is 12 milli-seconds. This makes sense as each fuel minor loop occurs every 12.5 milli-seconds. No need to overlap injector firings.

Any PW over 12 milli-seconds is saved for the next loop around.

The minimum allowed time is the shortest allowed async injector PW. If shorter it is saved for the next loop and added to that loops value. Once the value is greater then the allowed minimum the injector will be fired.

Note that AE is always async fueling mode. So the min & max async PW terms are also used for AE. Looking at a 7.4l TBI calibration you will find the minimum async PW as large as 1.4 milli-seconds. When used on a 5.0l or 5.7l engine this causes a 'chunky' AE. You can actually feel when the injectors are fired.

RBob.

 

Thanks guys this is all starting to make sense now. I have my part throttle about 90 percent of the way now and my idle is almost where I want it, no surging and pretty smooth at that.

I'm now moving on to wot and I'm having a ton of problems. It has a horrible top end miss. It starts at about 4 grand and the motor just quits pulling by 5. The first time it did this I saw the O2 peg over lean, below .45. I kept adding fuel and adding fuel and every time the O2's would come up higher and higher. I am now at .990 to 1.01 as soon as I get PE mode, and it's still cutting out.

It sounds like it's a lean miss. I've replaced the plugs and the coil and checked the fuel pressure, I don't really have a way to watch it at speed though. I know the o2 sensor is about junk for wot but it at least told me what direction to go in. Could this still be a lean miss and the O2 is just out to lunch or should I start looking into some kind of an ignition problem?

 

You are probably still lean. Ignore the NB O2 sensor. Go by the gut. Best bet is to put a fuel pressure gauge on and make sure that it isn't dropping off.

There are things that can be done to see if it is lean. If your timing is currently conservative add 2-3 degrees. Is the misfire less? Then it is lean.

Another thing to do is when it starts to misfire is to slightly raise the go-pedal. Is the misfire less? Does it suddenly start to pull? Then it was lean.

Too rich just causes a loss of power, unless the engine is drowning in fuel. . .

RBob.