Rich Idle - Please Help!

[hquick]

IMHO, no injector change should be made without getting the offset table, measured flow rate, and min pulse width programmed correctly.

Couldn't agree more.
This is why I've been spending ALOT of time trying to find the correct info. It's like the preverbial 'ARK' to find.

[hquick]

Well..this is what I decided to do.

I used that Ford lightning to LS1 converter.
I put my original VAN tune numbers in the single line table on the first sheet.
I put my original VAN tune injector pulsewidth voltage adjustment table where it says original table and then I copied and pasted the corrected table into my tune...(attached).
I used the figures from this thread for the min pulse width: http://forum.efilive.com/showthread.php?t=7790
I put my VE back to stock...with the exception of the high section at the top.
I ran an auto VE on the way home.
So...starting again! Lol!
Before and after tune attached.
I'll run the auto VE for a few more days and see how it pulls up.
I'm now at the rich idle stage same as you Dan.

[hquick]

After the auto VE.

[white01ss]

I'm now at the rich idle stage same as you Dan.

I'm sorry!

Hopefully, I'll make the time to put my wideband in over the next weekend so I can compare AFRs with you, but I would bet it's running about 13:1 the same as yours.

From your log, the commanded AFR at idle was 14.52 and your wideband averages 12.6:1 (> 140 F ECT). That's a pretty big spread. You're in OLSD, so no MAF, no LTFTs, no STFTs, and no O2s influences. That leaves VE, IPWVA, Small Pulse Adj and IFR. Your pulse width voltage adj table is .79 at 13V and .66 @ 14V which is really close to mine +/- 0.1 ms. And at 6.4 g/s, your IFR is pretty close to mine.

So what makes the idle range so rich? Is it possible that the injectors flow more at these small pulse widths than the PCM is being told? Howard, want to try lowering the IPWVA table from 70-80 MANVAC? We could also try bumping up the IFR in the 70-80 range and see if that leans things out.

[hquick]

OK...tried a couple of things.

One....as I have the Walbro 255 in there and my fuel pressure guage seems to be dicky...or something...I re-calc'd nmy IFR using the 62 Psi I've seen used by quite a few other Walbro owners.
Also....
Here's some more info I just found.

Copied from their Tweecer Beta3 tuning guide.

All Rights Reserved (c) 2001-2006 STKR, LLC
ÓSlower Traffic Keep Right, LLC
www.TwEECer.com


Injector Specific Parameters


Ford uses a dual slope + offset calibration design for fuel injector pulse width calculations and depending on which year your calibration was created; there are a few differences in how the parameters are handled.

Injector Slope High (AHISL) represents the size of the injectors at the expected 39psi of fuel pressure with zero vacuum. Below is a table of the values we use as starting points. With injectors of 36lb or larger, we use the size value multiplied by 1.15-1.2 for the low slope. You may need to adjust these +/- for your setup but these will be in the ballpark.

Injector Slope Low (ALOSL) represents the size of the injector at low pulse widths where the injectors are a bit sloppy and perform like a larger injector.

Injector breakpoint (FUEL_BKPT) is the point at which the EEC switches from Hi to Low and Low to Hi injector slope in the fuel delivery calculations.

Minimum Injector Pulse Width (MINPW) is used to maintain a repeatable fuel delivery calculation. Does not apply to MOST pre-94 models.

Injector Size- High Slope- Low Slope- Breakpoint-- Minimum PW
19lb--------- 19.5------ 26.5 ------0.00001725-- 0.00000750
24lb--------- 24.5------ 30.5------ 0.00001925-- 0.00000500
30lb--------- 30.5------ 38.5------ 0.00001975-- 0.00000500
36lb--------- 36.5------ 42.5------ 0.00002025-- 0.00000400
38lb--------- 38.5------ 45.5------ 0.00002250-- 0.00000400
42lb--------- 42.5------ 50.5------ 0.00002500-- 0.00000400
50lb--------- 50.5------ 60.5------ 0.00002500-- 0.00000350
55lb--------- 55.5------ 66.5------ 0.00002500-- 0.00000350
83lb--------- 80.5----- 100.5------ 0.00003000-- 0.00000300

Injector Offset Vs Battery Voltage (FN367) is a function to compensate Pulse Width adder, when the battery voltage is low. The stock values for 19lb injectors are too large for 30lb and larger injectors and should be adjusted down. I start adjusting beginning with the 10v column and work up to the max column, usually 15.xx.

Use the values listed below as a starting point, they should work well for each application.

Injector Size 10----11-----12-----13----- 14---- 15 volts
24lb-------- 1.35- 1.15--- 1.0---- 0.925-- 0.75-- 0.75
30lb-------- 1.3-- 1.11--- 1.0---- 0.90--- 0.725- 0.725
36lb-------- 1.25- 1.075-- 0.975-- 0.825-- 0.7--- 0.7
42lb-------- 1.15- 1.0---- 0.925-- 0.75---- 0.5-- 0.5
83lb-------- 1 ----0.95--- 0.7---- 0.5----- 0.25- 0.25

[hquick]

And some more info....

[Chuck L.]

Following this thread, and have a "newbie" ??
Given that the batt volts in the system rarely, if ever, fall below or above the "normal" 12 to 14 VDC, why even worry about the offsets, etc, that are outside of this range?

[redhardsupra]

ChuckL, because voltage takes a good swing sometime, put a voltmeter on the fuel pump and start the car, or go WOT into high rpm sometimes, and you'll see how much the voltage can drop sometimes.

hquick....let's talk

[hquick]

Yes Marcin...I'm all ears.
The injector side of things is all new to me so go easy on me. Lol!
The way I'm looking at things at present...I used to have 19lb poppet injectors sitting inside a horribly cluttered intake manifold being force fed air via a Whipple and the PCM being 'tricked' via the Whipple BAP system (older unit...no aux injectors).
Now...I have the Marine manifold which is very clean inside with no clutter and I'm using 'regular' style 42lb injectors.
I can't understand how I can make this swap and with the exception of the IFR, still be using the same settings as the 19lb poppets?
With all of your experiments and data Marcin, can you please explain it to me?
This 'injector play' all resulted from getting 'audible' (but not collected via datalogging) pinging at around te 2000 rpm, 30-40kph, 80kpa and above area.
At present I'm spending all night on the net trying to find as muchinfo as possible on these injectors and then I'll probably go with the 'most common' data.

[white01ss]

OK...tried a couple of things.

One....as I have the Walbro 255 in there and my fuel pressure guage seems to be dicky...or something...I re-calc'd nmy IFR using the 62 Psi I've seen used by quite a few other Walbro owners.

Howard, have you performed another log since the change to IFR? You were running 12.6 at idle before, what is it now?

Good news... I've got my wideband in!!!! Need to hook it up to EFIlive and do some scanning next. Also, put in boost and fuel pressure gauges at the same time. The fp gauge says 64 psi at idle, so I will update my IFR accordingly and see what happens.

While testing the wideband at idle, it showed 14.6-15.1 AFR. I was expecting much lower than that, but it did seem to oscillate way too much. I might need to calibrate it again, but that what it shows.

Questions:

Q: What is a good AFR scan at idle supposed to look like? Should it stay on 14.7 or will it normally move around a bit more?

Q: I found some information about headers making the narrowband O2 sensors see leaner than normal and the PCM responds with more fuel. Has anyone successfully manipulated "B4105 O2 Switch Point" and B4109, B4110, B4111, and B4112 to produce a good steady 14.7 AFR?