When I get home today I will post some data that shows the trigger point when the engine almost stalled and it also shows the data before and after the moment when it almost stalled. I just haven't made sense of it yet.

 

Here is the scan data. The top columns show data points. The trigger point is when the engine almost stalls and then the letters go into positive territory which signifies data after the trigger. I had to do two screenshots because it's too big to show in one screen. The rows I highlighted from top to bottom are: Engine RPM, BLM, Map Sensor, Spark Advance, Inj Pulse, Rich/Lean indicator. You'll need a ruler to follow the other rows on the second screenshot. The first screenshot goes from -N to -D and the second continues from -C to +I. Is there anything in there that throws red flags to any of you guys?

 

I see it now. You iac isnt doing anything. It is all the way closed so you have the throttle body open too far. Iac is from 45 to 160 for min and max and you are at 45 so it cannot go any lower to acheive the 850 you are asking it to see since it is idleing at 900 to 1000. It is pulling timing to try to bring it down to your 850.Close your tb blades a few turns so the iac counts come up to around 100 and once it learns it will clean up. The best way for it to learn it to drive at 45 to 50 mph. That should fix your hunting idle. Im so smart.hehehe.

 

The timing seems low but maybe your scanner is just showing what the ECM adds?

Anyway I like to set my TB blades so I have 10-20 IAC steps at idle in N.....
( depends on rpm adder for N and so on but I like my IAC steps to be low to prevent stalling out in traffic if I close the TB quickly)

Another thing you could try is when @ idle try to increase the TPS ( not the blades) to see if it calms down, I use 0,5mm feeler gauge.

 

I think you still have too much fuel. I would try and get your inj pw down to around 0.9 - 1.0 ms at idle (or even lower) to see if it helps.

For comparison, my car idles nicely at around 0.75 ms on 42# injectors at 800 rpm. I also run a little more spark advance (currently 26 degrees) at 800 rpm.

 

In the $6E bins (at 3AC/3AE) there is "Default Pulse Width if calculated PW is <= to" and a "min base pulse width" (both are 1.59 ms in stock arap). My injector spec sheet has this at 1.05 ms, so I lowered it.

In your bin, if these are not lowered, your engine will drowned in fuel at low ms.

Your lowest is .7 ms but it does not stay there. The normal idle is 1.4 or twice that.

My idle with 24# inj at 50# FP is at 2.2 ms with a 42# it should be way lower.

 

At -E 523 O2 72 mv rpm 928
At -D 524 IPW 1.7 ms IAC 2 rpm 1072
At -C 525 IPW 2.0 ms IAC 1 rpm 744
At -B 526 IPW 1.5 ms IAC 1 rpm 1357

This is the "dog chasing it's tail" When the O2 goes cold it signals a "false lean" condition which increases the IPW and the roller coaster ride begins.

The O2 feedback is the first trigger what upsets the steady state.

notice at + f,g,h,I O2 is 0 mv, the next few logs will be very rich.

 

Just a thought...
My engine hunted at idle when the Holley (piece O crap) AFPR diaphragm was leaking fuel.

 

How do I go about reducing my pW? Is that done by lower the numbers in the VE lower table where my engine is idling at?

 

Ya know it's a good thing that I started this thread because I've learned so much from you guys. For some reason the board's instant email notification wasn't working because I just got everyone's responses. I will start messing with the car again and report back. Thanks!

 

From ARAP $6E:

;==============================================
; FUEL OUTPUT PARAMETERS
; calibration = msec * 65.536
;
;==============================================
LC3AB: FDB 0104 ; 1.580 msec Min Base PW
LC3AD: FDB 0104 ; 1.580 msec Default Pulse Width

I do not know where in other bins.

Each brand/size injector will have a "calibration sheet", these are engineering data, so you can set up the injector controlling software to flow "linear" and stay within the injector's design limits.
----------
In his data log the IAC steps are "0-20" not sure what the "45" number is.

 

get the blades shut some and all will be much better. That is a huge problem. Know because I went through it once. Will quit the hunting. Might still be rich but should not go up and down. WIll probably just have a flat idle with out a good cam sound.

 

Low Inj Pulse Width Offset vs Base Pulse Width $32B ABTC (location 3C3)
Inj Offset for Small PW's vs Base PW $32 BUA (location 3BC)

There should be a similar table in your bin, this table adds ms of time to the IBPW to increase the fuel flow. It starts at 2.2 ms IBPW and increases added time down to .488 IBPW, this is below the OEM 1.59 or 1.66 min pulse width.

This table is, installed injector specific, so with the bigger injectors this time will be less and with the lower designed min pulse width of the 40# injectors, the added fuel can be started at a lower IBPW.

This table is to make up for the time lag of the driver charge time and the mechanical lag of the opening of the injector pintle.

New style disc type injectors have shorter opening times, so you can get extra fuel because, of the miss match of the table vs the "real world" of the "installed" injector flow.

 

Update: I closed the throttle blades some and now the cars starts but stalls right away. If I even touch the throttle blade screw just a little then the car goes back to the idle hunt. I'm about to rip this Superram out and go carbed. Would valves not adjusted right cause the search for an idle as well? Superram , 7730 ECM, SD harness, etc for sale soon if I can't get this to work.

 

not sure why $8 is giving you such a hard time but code 59 idles great for me on ford green top 42's with a super ram and 8.5:1. maybe before you swap to a carb. pick up a 3bar map and dump it in your 730 ecm and run a few auto tunes.. I think you will be impressed. I know I'm just tuning $8d for the first time on a stock 305 5speed tpi car and can not get the driveability where I want it in a week of trying and 30 chips. I'm about to switch to 59 for my gf's stock n/a car just cause the ae and de are so much easier to tune. just a thought.

 

What do you mean by code 59? Will that run in a 7730?

 

if you do a search there's a ton of info on it, but real quick. its the code for boosted cars that has been redone on the code level. check code59.org for a how to thread for 730 ecm's. I have a 730 with it using it and my base .bin for the 42's is posted up as a starting point. you will need to buy a 3bar map sensor.

 

I believe I may have figured the problem out. Here is a screenshot of my lower VE tables graph. Notice the dip in the 60-80 kpa range (which is where my car idles). I believe I may have caused my own problem in an effort to correct a rich idle condition and the ecm went haywire adjusting PW. I think the range is too great for the ECM to adjust and it's getting caught in an idle loopty loop. I'm out of town this weekend so I can't apply my findings but what do you guys think? Could this be my idle problem?

 

pwdbychevy, I may have missed this but before I answer. Are you using a wideband 02?

 

I'm using a NB sensor for the ECM and a LM-1 WB further downstream for data.

 

ttt

 

I think so.

RBob.

 

Hey RBob, should I have lowered the entire lower table instead of where the car idles ?

 

It depends. How is the AFR when in the other areas of the VE table? If you are running closed loop there is a separate set of values for the O2 window while in idle. There is also the AIR divert adjustment to the off-idle O2 window.

RBob.

 

Other areas show rich. AIR is disabled.

 

try lower the table in the other areas or atleast smooth it out, you dont want sudden BPW changes at idle.

With bigger inj smaller changes is needed to get results.

/N.