Accel Enrich on while using VEAL

[pdub]

Hi guys,

Jut got my FI installed. I had been running wasted spark only before. Anyways, Mario hooked me up cuz he supplied all the goodies, I bolted them on and the damn thing started on the first try I did use a pair of old Italian Webers as ITB's (they had bad fuel passages). My question is when running VEAL it states to have accel enrich on as you would normally, but I have read and heard elsewhere to leave it off I might not get the VE map correct-ever. What do you guys do/think? When I leave it off it has one nasty flat spot off idle and a pretty good hiccup between shifts so it isn't too much fun to drive around using VEAL with the flat spots, but If I have to I will.

Also, what do you guys with around a 2276 and ITBs find your accel enrich settings at?

[Piledriver]

VEAL ignores the accel shot, but YOU will likely prefer to leave EAE/accels off until the VE table is well tuned, which could take between 30 minutes and days depending on if you have hills nearby... EAE will not work reasonably until VE is tuned OK, so the car will not run well. Just turn the accel threshold up to 5000 or something until VE is tuned.

VEAL does, however need a reasonable lambda delay table to work well while RPM/load varies, and the default table is not unless you have a Cheby (or perhaps Mk1 Golf) with iron headers with the WBO2 8" from exhaust ports.

The table is only part of the project, not part of the msq... has to be exported/imported when you begin a new project on new firmware. MS3 is growing a similar table in the firmware so idle and LTT can work properly, still a work in progress.

[pdub]

Thanks. It's a real bear to drive w/o accel shot. A real pain in so cal traffic. I have to rev the poop out of it before I can let the clutch out.

[Piledriver]

I don't run ITBs since going EFI so far so I cannot advise in detail...
(likely to happen with the 2466 and 44 IDFs as TBs though)

I'd first try to get a reasonable VE table then turn on EAE. first, then perhaps regular accels only playing with the thresholds and MAP/TPS %.

You are running ITB load mode, right? (in MS2-extra and MS3)

[pdub]

I did some digging through the archives and saw K-Roc, 56speedter and others had the same issues about a year ago. I'm pretty sure they were both running ITBs as well. I took their advice and took the TPSdot threshold down to single digits and wow, much better, almost no flat spot. I could totally relate to Devastator's remark of something like "if I'm going to drive around without accel enrich on I better have a fresh battery" The flat spot is so bad off idle it would die if I didn't rev it up to like 2K first!

Hopefully VEAL will indeed ignore the accel enrichment but it is practically unsafe to drive on the street without accel enrichment on.

I'm not running EAE and I have no idea if I'm running ITB load Mode Where is that setting? I might have to ask Mario about that one.

On a side note, VEAL has leaned the crud out of my low KPa low-mid RPM range VE table which is fine for most aspects of my driving but I think that is why when I am decelerating and in gear, especially on a downhill, it goes super lean and I'm getting manifold popping. If I throw it in neutral the AFR returns to normal but that isn't always feasible.

[Piledriver]

You should probably play with the decel fuel cut settings so it works properly.
If you are not spraying fuel on decel, will not pop, or waste fuel.

[pdub]

Thanks Pile. I will re-examine my decel settings. I think I have it set to "100" which "cut no fuel on decel."

[Steve Arndt]

I do decell fuel cut when MAP is below 35kpa and throttle less than 2%. It is quite smooth and drives nice that way. You wouldn't know it was doing the fuel cut without a wideband to watch (seamless).

O

[Piledriver]

Do try the lambda settings, I find VEAL works very poorly except at steady state with the default settings.

once set up the fuel cut and accel shots will help you find the right delays.
(EDIT---)The table I posted...Should be close for a typical vw header.

[MarioVelotta]

Yeah you can turn the Overrun-Fuel cut on in the Fuel Settings menu. I keep most of these "extra" features turned off in base tunes. Nothing like possibly adding more odd behaviors to a new system.

I like to use the scatter plots in Megalogviewer to set this up by looking at the overrun line while mapping RPM Vs. Map

Sorry I don't have a pic of that available

[pdub]

Thanks Mario. I just checked it out and it was on already. I reset some of the parameters so hopefully that will help. If not I will turn it off altogether and see what happens.

[pdub]

Just a quick update:

I loaded Pile's lambda settings, turned fuel over run fuel cut off-it was on, and ensured decal fuel percentage cut was "turned off" under AE settings. I then turned the after start and WUE settings down and backed off the AE enrichment (speed setting) to double digits again. I ran VEAL and it just leaned the crap out of my VE map. My engine with ITBs, Engle 120 and 9:3 CR didn't appreciate it. I stopped the VEAL silliness and tuned the VE map myself based on watching my AFR gauge (dangerous) and looking at some logs. While the AFR isn't in that lean the decel backfiring and cruise surging has stopped. My AFR was bouncing around a bit but I think I may have been getting some AE shots because I have to run AE dot values at silly low numbers with the ITBs. Now that I've richened up the VE map a bit it seems I can increase AE number (so it doesn't activate with slightest throttle movement) and not have it stumble on its face.

FWIW my AFR seems to like to stay in the mid to high 13's with maybe some 14s at cruise.

BTW I am running speed density and not ITB mode. One day I may experiment with ITM mode but just trying to get this dialed in first.

[ps2375]

What does your target AFR table look like, the VEAL function won't work very well it that table is not what you want, after all, it is using that table to adjust the VE table. I learned that lesson on my first install/tune, after I figured that out, things came into tune very nicely. And you can tune the pops out of decel with your settings on this table too. I had them tuned out of my decel on my last car and had over-run fuel cut turned on, but, I always was pleased to hear the pops on decel when the car was still in WUE on the way out of neighborhood. Always thought of adding some fuel to the decel part of table and adding some time before fuel cut.

[pdub]

Good point, Thanks! Being a rookie I sort of forgot VEAL was using the AFR table Even though the AFR table didn't seem to be overly lean, it was around 14.3 where VEAL had plugging in very low VE values that resulted in surging at cruise and popping in manifolds on decal (with no decel fuel cuts). Even though I've got the VE table close now I'll plug in some richer values in the AFR table and let VEAL do its thing. I'll do a "save as" of my current tune/VE table first though!

Apparently Pile and others can get their built motors to cruise at 15 AFR + but my motor isn't having none of it. Is it an ITB thing where it needs to run richer in general and why those lean/well past stoich values aren't working for my motor? Is that what you other guys running ITBs have found in general?

[trbugman]

You need to have a good strong spark and enough ignition timing to run lean.

The easiest way that I have read to tune those areas is to lean it out till it surges then add in some timing until the surge is gone. Rinse and repeat until you can't tune out the surge.

Doing this alone won't be easy, but with table blending and 2 pots(one for ignition, one for fuel) it could be a heck of a lot easier.