The Project Pad

So I'm fiddling around with the car trying to pass CO emissions, and sitting in line to get tested today I notice that lambda is decreasing as the car sits and temp rises. It eventually gets to the point where it's at 0.7 at idle and 0.9 under throttle and it won't even run w/o throttle input. We had to abort the emissions test because it kept dying on the dyno so I let it cool off for about a 1/2 hr. It drove home just fine until I hit some stop and go and the temp went back up - and it started running rich again and dying.

Any thoughts? I don't have a log for it since my laptop only has about a 20-30 min battery....

Thanks

What software are you running? Look at the MAT enrichment

Vems, version 1.1.96. I'll see if I can get a log file tonight to get some more info, but I'll look at the mat enrichment.

You can attach a config to your post, that would be helpful in diagnosing. I would:

1) Check your warmup enrichment curve, make sure it's all 100% after operating temp
1) Make sure your MAT sensor is working properly
2) Check the MAT/TPS enrichment table

All the things Ed said are great places to start. What are you running this on? If it's an AAN, or similar triggered Audi, I would recommend running firmware 1.1.95 as there are some problems with auditrigger in .96. That's not related to your problem, but .95 is way better than .96 in this. Anyway, you can get into checking calibration of your WBo2 sensor and also make sure that the correct patches for the MAT and CLT sensors are installed with your firmware. If those are wrong you can get some incorrect values.

Just to catch everyone up, this is "The Red Pill" and I've been trying to help Brandon out, remotely, with calibration so that it passes emissions. From my view, the config has some strangeness (High Req Fuel, low VE range, high warmup enrichment, lots of cranking fuel). I am also not sure what lambda targets should be used for NA.

Of course today was in the high 90s.

This is the config from before we really changed anything (I think).

Well, I took the car in before it hit 90 today and it passed so now the fun can begin. It'll be pretty damn hot this afternoon so I'll take it out and get a log after it gets all warmed up. I passed a new brewery on the way to the emissions testing facility...

"Anyway, you can get into checking calibration of your WBo2 sensor and also make sure that the correct patches for the MAT and CLT sensors are installed with your firmware."

Which ones are the 'correct' patches? I did recalibrate the wbo2 when I got it home to correct for altitude so that should be good to go.

What motor is this running on? Your warmup enrichment curve is causing the issue.

You need to have a cell where the car is fully warmed up that indicates 100% fueling (no enrichment). The way it is set up now it never turns fuel enrichment off. It is also really rich.




Here is an example of a typical AAN enrichment curve:

Yeah... that enrichment curve is like whoa

So, we made corrections from that file but because of time we did not rescale the warm up. Am I missing something, if the VE/Req fuel is 46% low when warm then the total enrichment is ~100% when warm, right?

I'm not sure I understand your question.

I suppose you could compensate for warmup enrichment by decreasing VE, but that is one back asswards way of doing things. The VE table is also all over the f'ing place

Wow. That VE table IS all over the place, like Ed said. I don't know what you've already gone through with your set up, but I'd seriously rethink the strategy a bit here. First of all, turn off that barometric correction shit. It really doesn't work well and any changes in fueling can be made up by EGO if the car is run at a different altitude. I tried messing with that a bit and found it to be not worth the trouble, at least until they get the kinks ironed out of the "dinamic" mode.

Baselining the reqfuel, warmup enrich table and the VE table is a must. Then tune the little stuff like acceleration enrichments, etc. around that. It shouldn't take too much work to get it running well from there.

Ed, you got what I was saying in your second paragraph.

Let's recall that this was "as delivered" and most likely tuned by the original builder, ~2 owners removed from Brandon. As stingy as CO is with temp tags the #1 priority was to get it to pass emissions. Now that it passed he has 2 years to play around and, hopefully, drive by some roadside test vans.

Here is the updated config, more or less what passed today, I was worried about issues between our firmware (and time constraints) so I did not change too much. The VE table is still a bit scattered but not as bad

That VE table looks much better but the warm up enrich table is still off. It should be tuned so that it's at 100% when warmed up. I don't know the history of this car really but like I said before, I don't think it'll take much to get it right. It just looks like the foundation is a bit off...

Yeah, like I said time limitations drove the make it pass mentality. While the warmup is weird it is an easy fix and, seemingly, not a problem since the rest of the calibration is working around it.