Rich Idle - Please Help!

[white01ss]

Just started tuning in Jan 08 so please bear with me...

The problem is that the car is rich at idle and a lean when cruising. It's got a S/C on it with SVO/Bosch green top 42lb injectors and a Racetronix fuel pump. Stock MAF w/screen.

What I've tried so far:

1) B4001 The IFR table is dialed in according to the injectors.xls
2) B3701 The Inj Pulse Width Voltage Adj table is dialed in. Got specs from Ford to adjust this table. The car was VERY lean in the 35kpa and up columns before bumping up that table. Tried pulling down the 30 kpa and under rows and it didn't make much of a difference.
3) B0101 Been tweaking on the VE table based on LTFTs and it's made a lot of difference in the 35kpa and up trims, but almost no difference in the 30kpa and lower under 2000 RPMs.

I noticed that my Injector Pulse Widths at idle have had a range of 1.892 to 2.107 ms. I can't seem to get the PCM to command a pulse width shorter than 1.892 ms even when the injector can do 1.13 ms!

I know, I know. I need a wide-band and do the AutoVE. I'm getting one in a month or so, but the car's inspection is out so I need a quick fix just so I can get it inspected. Right now, you can just smell the fuel when it's warmed up and idling. Any one have any ideas?

Thanks,
Dan

[white01ss]

Here's a version before where I raised the B4307 Desired Airflow 5%. This was to help the lean upper RPM cruise problem. B4308 Airflow Parked is also a little lower.

[white01ss]

bump for my stinky car

[hquick]

Hi Dan,
how did you come up with the IFR's in your tune?
I used the attached sheet (after searching for MANY hours on the net) and used 43.5 as the standard pressure for calc'ing the new IFR. I know alot of people say Ford use a diff pressure for calc static flow...but Marcin (REDHARDSUPRA) had 2 sets tested and at 43.5 they flowed close enough to 42 to call it OK.
This would mean your IFR table should look like:

6.110675
6.148759
6.186608
6.224227
6.261620
6.298791
6.335744
6.372483
6.409011
6.445332
6.481449
6.517367
6.553087
6.588614
6.623950
6.659099
6.694063

Also...how did you come up with the B3701 table and the others?

Thanks

[jfpilla]

Howard,
In the IFR calculator, I believe the 0-80 column should be labeled
MANVAC(kPa).
Joe

[hquick]

Thanks Joe...I don't think I can change it..I found it somewhere online.

[jfpilla]

Howard,
It wasn't locked, so I changed it.
Joe

[hquick]

Cool..thanks Joe.

Howard

[hquick]

Here's another injector sheet.
But...how do I use it?

[white01ss]

Hi Dan,
how did you come up with the IFR's in your tune?
I used the attached sheet (after searching for MANY hours on the net) and used 43.5 as the standard pressure for calc'ing the new IFR. I know alot of people say Ford use a diff pressure for calc static flow...but Marcin (REDHARDSUPRA) had 2 sets tested and at 43.5 they flowed close enough to 42 to call it OK.

Howard,

I used the following numbers. I have a Racetronix pump and the pressure is a little higher than stock.

Injector Rated Fuel Pressure: 39.5
Your Fuel Rail Pressure: 62.5
Injector Rated Flow Rate: 42

Injector Flow Rate (Grams/Second)
Manifold Vacuum kPa {link: GM.MANVAC}, Value
0 6.656250
5 6.695313
10 6.734375
15 6.773438
20 6.812500
25 6.851563
30 6.890625
35 6.929688
40 6.960938
45 7.000000
50 7.039063
55 7.078125
60 7.109375
65 7.148438
70 7.187500
75 7.218750
80 7.257813

Also, the car was already running rich, so I didn't want to make the problem worse by lowering the IFR.

[white01ss]

Also...how did you come up with the B3701 table and the others?

For B3701 I used this speadsheet I found on the Internet (maybe here I can't recall) that uses an equation to extrapolate the table from a given set of base values. Entering the voltage offset values that Ford gave me it give the entire table. I also tweaked some of the excel formulas in the upper voltage ranges (15+) because they were dropping off too fast.

[white01ss]

I wonder if anyone can answer this...

B4001 Injector Flow Rate says:

"If the fuel rail pressure is NOT referenced to manifold pressure, then decreasing the manifold pressure has the same effect as increasing the fuel rail pressure. The fuel flow rate of the injectors will increase at higher manifold vacuums (i.e. lower manifold pressure)."

Now, shouldn't the injectors flow MORE at 0 kPa (perfect vacuum) and LESS at 80 kPa? The stock tables seem backwards.

Injector Flow Rate from 2001 Z06

kPA (Grams/Second)
0 3.671875
...
80 4.023438

Assuming that the fuel pressure stays constant, flow rate should decrease as the manifold pressure increases (especially from FI). An extreme example, if the fuel rail pressure is 58 psi and boost is 58 psi, wouldn't the IFR be 0 or at least close to zero?

Back to the Idle Issue.....

I know this is ugly, but I've been experimenting with an IFR table bumped up under 35 kPa to lean out my idle/cruise.

It actually help quite a bit in getting the trims inline. Also, when I turned off the MAF the >30 kPa trims came down to negative for the first time since putting on the blower/injectors. Apparently my stock MAF was out 25-50% in the upper freq ranges wreaking havoc on my trims.

Injector Flow Rate (Grams/Second)
kPa Value
0 6.984375
5 7.000000
10 7.015625
15 7.031250
20 7.046875
25 7.062500
30 7.078125
35 6.773438
40 6.812500
45 6.851563
50 6.882813
55 6.921875
60 6.960938
65 7.000000
70 7.031250
75 7.070313
80 7.109375

[joecar]

The kPa scale in B4001 is not MAP, but it is MANVAC.

MANVAC = BARO - MAP

That's why it looks "backwards", but it's not.

Perfect vacuum is MAP = 0 kPa (like you said), giving MANVAC = BARO - MAP = 100 - 0 = 100 kPa.
Zero vacuum is MAP = 100kPa, giving MANVAC = BARO - MAP = 100 - 100 = 0 kPa.

And that's also why the MANVAC scale only ranges upto 80kPa...
because at MAP 20 kPa and below, the injectors won't be required to spray much fuel if any.

[white01ss]

Thanks Joe! I just read your thread about IFR calculations. Very nice. That makes much more sense now.

http://forum.efilive.com/showthread.php?t=4821

So, for the Z06 example:

kPa (Grams/Second)
0 3.671875
...
80 4.023438

WOT would be at 0 kPa, and idle/cruise would be in the 70-80 range?

[hquick]

Dan...have you seen these values?

[joecar]

So, for the Z06 example:

kPa (Grams/Second)
0 3.671875
...
80 4.023438

WOT would be at 0 kPa, and idle/cruise would be in the 70-80 range?
Dan,

[I hope I got your name right...]

Yes that is correct.

Cheers,
Joe
:cheers:

[hquick]

Current tune and log...for your reference Dan.
OLSD, 5.7L Whippled with the 42's.

[white01ss]

Dan...have you seen these values?

No I haven't seen those before. They seem pretty close to the one's I posted in the 10-12 V range, then they start to deviate quite a bit. I wouldn't trust it too much without specific part numbers because they may have changed them over the years.

I know my car ran like poop on the stock table and I couldn't believe the difference changing this table made in the drive ability of the car. IMHO, no injector change should be made without getting the offset table, measured flow rate, and min pulse width programmed correctly. But what do I know, I just started in Jan 08! :cucumber:

[joecar]

You're doing fine, don't let post counts fool you... :hihi::hihi::hihi::hihi:

[white01ss]

Yes that is correct.

Cheers,
Joe
:cheers:

Thanks! :master:

So I've been dickin' around with the wrong part of the tables! (IFR, IPWVA) :wallbash: I'm lucky I haven't blown up my freakin' motor. Good thing I've only been doing small changes.

[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! :doh2:

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?

[white01ss]

Connected the LC-1 to the scanner this week and did a short logging session. Yesss, it worked! My wideband scan shows about .1-.2 lower than the XD-16 gauge. I assume the gauge is correct since it has a digital connection to the LC-1. I'll need to fix that, but the results are still pretty darn close.

So back to topic... Looks like I'm averaging around 13.5-7 AFR at idle. It seems to bounce all over the place. This was in CLSD so the front O2s/LT headers are probably causing some of my richness. Next step is to turn off the O2s and do my first OLSD AutoVE tune.

On a side note here's a summary of my WOT readings:



RPM Commanded AFR Error
3600 10.006452 11.3 13%
4000 10.006452 11.3 13%
4400 10.006452 11.6 16%
4800 9.907182 12.0 21%
5200 9.822727 12.8 30%
5600 9.571667 12.9 35%
6000 9.571667 13.3 39%


Holy smokes! It leans out like a big dog past 4800 rpm. Shouldn't go any lower than 12.2 or so on the upper RPMS, but I'm seeing 13.3.

[SSpdDmon]

I didn't read through the whole thread - but if you're still having problems with a rich idle due to IPWs not falling below 1.8xx, you can change that by zeroing out B4005 and adjusting B3701 until you get the IPWs where you want them. The reason why these tables work is because the base IPW is determined using a calc'd cyl. airmass and what's 'known' about the injectors (i.e. IFR). B4005 and B3701 are then added on top of that. Keep in mind if you go too low, you'll hear it on decel when the injectors don't fire appropriately - it'll " pop" a bit.

[white01ss]

... you can change that by zeroing out B4005 and adjusting B3701 until you get the IPWs where you want them.

I attempted that already but thought MANVAC and MAP were the same thing so I was tweaking the rows around WOT instead of idle! Now that I know what it means (thanks Joecar!), I will tweak MANVAC rows 70, 75, and 80 and see what happens.


The reason why these tables work is because the base IPW is determined using a calc'd cyl. airmass and what's 'known' about the injectors (i.e. IFR). B4005 and B3701 are then added on top of that.

I was wondering what the relationship of CALC'd IPW and IPWVA, thanks SSpdDmon! I assume that the Min PW is checked as the very last step, so if I set it to 2.5 ms then it would never go lower than that.

[SSpdDmon]

I attempted that already but thought MANVAC and MAP were the same thing so I was tweaking the rows around WOT instead of idle! Now that I know what it means (thanks Joecar!), I will tweak MANVAC rows 70, 75, and 80 and see what happens.



I was wondering what the relationship of CALC'd IPW and IPWVA, thanks SSpdDmon! I assume that the Min PW is checked as the very last step, so if I set it to 2.5 ms then it would never go lower than that.
I believe you are correct. :)

[white01ss]

Lowered my O2 Switch Point table by 8% and it fixed the problem. My idle/cruise AFR now averages 14.7. Also updated the IPWVA table by making each column the same value like hquick did which lowered the idle MANVAC range as well. These changes made other parts of the VE table lean and messed with the idle a bit, but I'll deal with them later.

Also fixed the commanded AFR problem by multiplying the 105 kPa column in the VE table by the BEN factor. Now my WOT AFR doesn't go over 12.0 and is very close to commanded. Again, I'm glad I didn't blow my motor. Thanks for everyone's help, let's go have a :beer:

[SSpdDmon]

Lowered my O2 Switch Point table by 8% and it fixed the problem. My idle/cruise AFR now averages 14.7. Also updated the IPWVA table by making each column the same value like hquick did which lowered the idle MANVAC range as well. These changes made other parts of the VE table lean and messed with the idle a bit, but I'll deal with them later.

Also fixed the commanded AFR problem by multiplying the 105 kPa column in the VE table by the BEN factor. Now my WOT AFR doesn't go over 12.0 and is very close to commanded. Again, I'm glad I didn't blow my motor. Thanks for everyone's help, let's go have a :beer:
Please post up a copy of your tune (or email me at SAJ79 at aol dot com). I'm curious to see where your injector values ended up for voltage adjustment, min pulse width, etc.

[white01ss]

Please post up a copy of your tune (or email me at SAJ79 at aol dot com). I'm curious to see where your injector values ended up for voltage adjustment, min pulse width, etc.

Sure... I didn't touch the min pulse width table, only the voltage adjustment. I think most of the improvement is due to the o2 switch point table.



{B4105} O2 Switch Point
Stock LT Headers
CL Mode Bank-1 Bank-2 Bank-1 Bank-2
0 365 365 340 340
8 435 435 400 400
16 435 435 400 400
24 435 435 400 400
32 450 450 414 414
40 500 500 459 459
48 500 500 459 459
56 550 550 505 505
64 550 550 505 505