I have a nasty bog around 2000-2500 RPM rpm and the O2's crash to 80mV and I get spark knock....
What would be good to try.... like 28 in the number of accel enrich pulses vs coolant temp and then scale the LV8 accel enrich factor va delta LV8 by 3. What else should I mod??? Please help??? Engine in sig...

 

You can probably pull most if not all your timing out at like LV8 150 to 256, in that 2-2.5K area.

And then you'll just have to see what your engine likes for the AE stuff. Try the 3 and see what it's like. I've had some stuff that I've gone to like 5 with.

I generally leave the temp coolant table alone. That's not to say you might have to. FWIW the changes in that can be somewhat huge.

 

I had some bogging on throttle tip-in after swapping to the Stealth Ram, worked it out by increasing values in the AE versus TPS and the AE versus MAP table. On the wide-band, the car's happiest when the air:fuel drops to the high 11.x:1 area on tip-in...kinda like a big accel pump eccentric on the old Holley carb.

 

post i did on ae a couple of months back

 

Funstick- thanks for being brave enough to put something down on AE in that post. I found it useful.

However, a few people got the irrits with both the content and with one another and the post died before the issues had been thrashed out.

Bruce- is the problem with that post in Funstick's confusion of AE with PE? You drew attention to the fact that you don't get AE on long hills under steady state conditions as Funstick claimed, because AE is switched via DELTA (change) conditions in LV8 and TPS.

I'm not familiar with these MAF systems at all, but I'm interested in how they work. Am I right to say, Funstick, that you're ascribing a PE function to AE? (BTW, I note that you didn't introduce this stuff as the absolute truth, but "from what i gather...")

John

 

Yep.
It's Accleration Enrichment.
Same as the acclerator pump on a carb., in function.

You can adjust it via a coolant temp compensation.
Min TPS to enable reading the delta TPS.
And then the amount of fuel by the deta of TPS or LV8.

Change the phrase Delta LV8 to Delta Map and you cover the S/D systems.

 

Read what I said here:
https://www.thirdgen.org/techbb2/sho...hreadid=184992

Tim

 

my comment on the LV8 enable for AE was based on the fact that long hills can enable the mode. its might be desireable with the engine expericneing an increase in load to allow this to happen. i was simply making a point to be careful what the minimum enables are.thats all. the rest i will testify to as being the most accurate description of MAF AE usage to date.

 

could someone help me out on the timing table.....this is what I have so far..I am gonna try it and see if I still bog...do you see anything thing wrong???

20.0 20.0 20.0 20.0 20.0 20.0 20.0 17.9 17.9 17.9 17.9 17.9
20.0 20.0 20.0 20.0 20.0 20.0 20.0 17.9 17.9 17.9 17.9 17.9
20.0 20.0 20.0 20.0 20.0 20.0 20.0 17.9 17.9 17.9 17.9 17.9
20.0 20.0 21.1 21.1 21.1 21.1 21.1 20.7 20.7 20.7 20.7 20.7
20.0 20.0 24.6 24.6 23.9 24.6 23.6 22.9 22.9 20.7 20.7 20.7
20.0 23.9 26.0 27.1 25.0 25.0 24.3 22.9 22.9 20.7 20.7 20.7
20.0 26.0 28.1 28.1 27.1 25.7 25.0 23.9 23.2 20.0 20.0 20.0
21.1 29.9 29.5 28.5 27.8 26.4 25.7 19.0 18.3 17.2 17.2 17.2
22.5 27.4 29.9 29.9 29.2 27.8 27.1 17.9 16.5 15.1 15.1 15.1
22.5 27.4 29.9 29.9 29.9 28.1 27.4 16.2 18.3 17.6 15.1 15.1
22.5 27.4 29.9 29.9 29.9 29.2 28.5 19.0 21.1 17.6 15.1 15.1
22.5 33.4 33.8 33.8 33.8 33.0 32.3 22.1 21.1 17.9 17.9 17.9
22.5 33.4 35.9 35.9 35.9 35.2 34.5 25.7 22.1 17.9 17.9 17.9
22.5 33.4 35.9 35.9 35.9 35.9 35.2 26.7 22.1 20.0 19.3 19.3
25.3 33.8 35.9 35.9 35.9 35.9 35.2 26.7 24.3 21.8 20.0 20.0
25.3 26.7 35.9 35.9 35.9 35.9 35.2 27.8 25.3 22.1 20.4 20.4
25.3 33.8 35.9 35.9 35.9 35.9 35.2 27.8 25.3 22.1 20.4 20.4

 

I reved it at idle on the scanner to 2000 and the think went lean and started to knock. I would think a good fuel pump would be able to keep the engine feed at idle. The BPW of the injector went to like 7ms but the O2 went to like 90mV.

Traxion I dont have a fuel pressure guage with a hose to hook onto the stealth ram fuel rails. Thats why I am trying to get more opinions.

 

Been there done it...when I swapped in my HSR and new AFR heads, mine was leaning out above ~4500rpm no matter what I did w/ the VE table. I finally ran a fuel pressure gauge to my windshield, took it for a blast, and watched my pressure drop to nearly 20psi as I passed 4000rpm. New Walbro pump fixed that.

So...drop $36 on a TPIS gauge w/ long hose and get it diagnosed.

 

Traxion...I made a longer hose for the fuel pressure guage and taped it to the window. The pressure went up as I got on it and stayed as the car stumbled. It did vary slightly due to the engine bucking but it went up and did not crash like I thought. So my fuel pump must be fine. But whats causing the stumble? I have the LV8 AE vs delta LV8 scaled by 5 and I have the number of AE pulses at 32? Whats wrong ?????? Help!!

 

OK, now that you have fuel pressure data you'll want to be sure you...oh wait, I'm not Traxxion...

 

Be good Kev or I'll ask for IMMEDIATE return of my piggyback (not that you need it anymore)

Kev is the guy to ask. He has exprience with the stealthram.

But, in any case the following does apply...

Were you at WOT (according to the computer) during the stumbling?
Did the stumble occur *immediately* after you opened the throttle blades?

Tim

 

It occurs a about 2200 RPm with about a little less than 1/2 throttle. If I floor it it has no power but will pull through the stumble/bogg/backfire range.

P.S. Sorry kev I didnt mean to play favorites but Traxion first told me to watch the pressure that way thats why I addressed the reply to him....sorry... your knowledge is more that appreciated.

 

anything else guys?

 

20.0 20.0 20.0 20.0 20.0 18.0 18.0 16 16 16 14 14
20.0 20.0 20.0 20.0 20.0 18.0 18.0 16 16 16 16 16
20.0 20.0 20.0 20.0 18.0 18.0 16 16 16 16 16 16
20.0 20.0 21.1 21.1 21.1 18 18 18 18 16 16 16
20.0 20.0 24.6 24.6 23.9 21 20 18 18 16 16 16
20.0 23.9 26.0 27.1 25.0 25.0 21 20 18 16 16 16
20.0 26.0 28.1 28.1 27.1 25.7 25.0 23.9 23.2 20.0 20.0 20.0
21.1 29.9 29.5 28.5 27.8 26.4 25.7 19.0 18.3 17.2 17.2 17.2

Try leaving the headers on, some of us look at enough tables, that it kinda blurs over time which increments go with which cal.. But, this should give ya a closer idea to work with.

 

I can't explain what he's seeing.
I can only explain what I've seen.

Run Mph Rpm KPa Tps CtsF MatF Spkf PW WB IAC PE AE PN
08:54 0 850 42 0 153 113 19.4 2.53 13.7 0 N N Y
08:54 0 825 42 0 154 113 21.1 2.53 13.7 0 N N Y
08:54 0 825 42 0 154 113 19.4 2.53 13.8 0 N N Y
08:54 0 850 42 0 154 113 18.3 2.53 13.8 0 N N Y

In my data logging I can see when I'm in AE, and PE.
Dunno where others get the data about when they're in what mode.

Like I said in the previous post I've never been able to see AE be sustained from hill.

I'm sure this will draw some snide remarks, too, but oh well.

Bueller?, Bueller?.........

 

With the ae mode being engaged by a delta lv8 (change in lv8), I would think it is possible to activate ae by going up a hill. If it changed from flat ground to uphill somewhat rapidly, the lv8 would also change rapidly, making the ecm think it needs to go into ae mode. Not proven by myself, just a thought.

 

It's delta load. Once the delta is over the AE stops after it's done with the PW for that load AE event. If you keep acclerating by leaning on the gas enough then as long as your acclerating then yes you can have AE. The hill is immaterial, it's the delta load that causes the load AE.

Get a WB, or scanning software and you can see that AE is transistional. Once it uses up the pulse width for that AE event it's done. There is a limit to each AE event for fuel. If you keep pressing on the gas, you'll hit PE.

Just as the accleration pump has a defined chamber/ volume on a Holley, so does EFI. And any entry in the cal has a max entry.

 

I understand the concept of the accelerator pump shot. I agree that once things stop changing the ae will decay out. I was just using the hill to show that even without moving the gas pedal, the ae "could" engage, by the change in the lv8.


Just went back thru and reread posts. I agree, unless the lv8 or tps changes enough to trigger the ae, it shouldn't be sustained, it would just be triggered and then decay, unless the tps or lv8 changed again to trigger it again.

 

For giggles twice now, once being this am, have tried and retried this, and I can't get it to operate in any fashion other then what I've stated, and no one has offered any settings where they could get AE not to decay out.
AE from what I've seen is to account for sudden changes in load, slow increases in load, need min if any. TBIs with the wet manifold design need more AE then the port systems, but even still it's only to cover until WOT or some proximity there of where the load is high enough to be at the high load areas of the fuel tables.

Maybe one of the Pro tuners can shed some light on what numbers to manipulate to get it to happen.

 

at what point did i ever argue that it wouldnt decay out ?? i simple mentioned that it would engage.did i misprint or misconvey something ?

 

That would be great! Any Pro Tuners in here?

Tim

 

personally id cut the decay values in half. pump shot could be plenty big enough but not long enough.

 

Maybe there is a place for a second board here,
where the pros can list their secrets.

 

huh and i thought the experts had already spoken. im not sure who your trying to call out but its both insideous and annoying. just be glad that some folks take time to come here and assist people. I dont think anybody would bitch if the guys from lingenfelter lurked on the engine board and shared info.