I've got an issue with bogging down badly on acceleration when cold (engine not warmed up). I datalogged some today and it appears to happen well after the system has gone into closed loop. What I noticed right away is that "rich flag" is on almost all the time. It comes out most of the time when cruising. What is the meaning of the rich flag when the system is in closed loop? The BLMs are not off the chart, for my short test run they ranged from 118 to 138.

Everything runs great once the engine is fully warmed up.

I also noticed that the "old high gear flag" is on all the time. This is an old engine with a 7747 mated to it. I don't have anything hooked up to the trans, and no VSS. Does that flag indicate that the fuel or spark is being done differently?

Thanks for any pointers.

 

All the "rich" flag really means is that your o2 sensor volts are high, it could be rich, or malfunctioning. Pull spark plugs to determine mixture.

Rich under cruise conditions makes me suspect EGR system needs checked.

 

In closed loop, if it's rich, shouldn't the system adjust until it's not rich? This is why I'm confused.

I have no EGR. I disabled it in the BIN, or I think I did. I set the min coolant temp for EGR to 300+ degrees.

 

Sounds like you created the problem & now expect the computer to fix it.

Believe me, the system is trying to adjust within it's ability.

Need more info, what type of car are we talking about? Engine?

 

Not sure what you mean. I had a non-emissions carb vehicle and switched to TBI. I just want it to work.

If so, wouldn't the BLMs be off the chart?

K5 Blazer with a 350, mild build, headers, no emissions stuff.

 

And what sort of bin are you using? What changes have been made so far?

 

ASDU was my starting point. I've made changes to account for the stuff I don't have (EGR, knock) and did a few iterations on the basic map to get the BLMs close. It runs fine warm and I drive it daily. It never throws any codes, it just has this issue when I first drive it in the morning on colder (for Tucson) days.

 

Ahh! I think you want to install a three wire (heated) o2 sensor,
unless you already have one.

o2's mounted in header collectors cool off too easy, high o2 volts mean the sensor is cooling off, sry I didn't put that in my first answer, but you gave very little info.

They (single wire NB o2 sensors) are supposed to stay hot, mounted close to the head in iron manifolds.

 

Good thought but I do have a heated O2. Sorry I didn't mention it before. The other thing I forgot to mention is that I have "cop car" injectors. I accounted for them by adjusting the BPW. Maybe there is more that I need to do to adjust for them?

 

Your goal will define the next action, to lean the mixture determine where it is too rich via datalogs & pull fuel from those VE cells.
To change the flag trigger, change o2 error parameters.
But,
I think you need to adjust AE PW to compensate for fueling changes & BPC settings.

 

If it's only happening cold, do I really want to mess with my VE table?

I'm not seeing anything (in TunerPro) that looks like AE pulsewidth, there are some accel enrich tables vs. coolant temp and other stuff, is that what you mean?

It's cool this morning, I'll grab some logs on my way to work. Thanks.

 

Are you certain you are in CL? I would think CL running would be at stoich even if BLM are 115-120. Unless at 118 being your limit to pull fuel. therre is a min and max set in your bin. Set it to 115 min and see if it drops to that.

what is your fuel pressure and what is your BPC?

there is a coolant compensation table for AE. I suspect you are using stock values there which should be OK. excessive AE will show up in a moving INT and resulting lower BLM. More likely more affecting INT and lesser BLM.

[QUOTEf it's only happening cold, do I really want to mess with my VE table?
[/QUOTE]

Most likely not your VE table unless VE table is so far off the mark. Certianly you could pull some fuel if BLM is 118 in those cells.

bogging due to excessive fuel? that would be unusual to me. Lean bog seems to be more common. you can address cool coolant AE in the coolant compensation tables. May want to move in baby steps to see if it improves. Check the values the coolant sensor is sending to ECU in datalog.

 

It is definitely happening in closed loop. I checked my bin and the minimum BLM is set to 108. I don't see anything that low in the BLM table from winALDL.

My ASDU bin is stock except for the BPW which is set to 122 to account for "cop car" injectors, and the knock, EGR and VSS are disabled.

I have an open element air cleaner. One person suggested that my problem could be do to lack of thermac heat. Is that possible? I wouldn't think you could be generating much heat in the first few minutes, but I'm not sure. I have headers, but there is a cheesy thing on them to attach the heat tube to.

I'd be very interested to know if people had to do significant mods to get decent cold weather driveability from a setup with open element and headers. And this is cool weather really (40 degrees and dry) not a carb icing situation.

I don't know if it's lugging down due to lean or rich. I need to record a shorter log so I can know for sure when the problem was happening.

 

My car has no heat to manifold nor TB to speak of. Yes it is a chalenge to drive car when the air temps are under 40F. When the TB plates open up the onrush of air condenses the atomized fuel and car nearly stalls or does stall. the walls need to be wet in intake tract and heat needs to be present to alow atomization. so a long warmup period is required to begin moving car. Once you feel heat at TB you should see decent drivability. My open loop tables(coolant under 160F) as slightly richer than stock. You could take them richer 5-10% and see how that works. also the AE coolant compensation you could enrichen same. One back to summer driving revert back to stock.

that is a good sign.

One thing I noticed is that on cold start when it flips CL the car drivability degrades as it goes from 13.9/1 to 14.7/1 and I lose that enrichment. so first stopsign it stalls but restarts.

 

Very interesting. I'll definitely give my closed air cleaner a shot and see if it helps. The open element is really just there to make the engine compartment prettier and make stuff easier to access (I have a smallish diameter but tall air cleaner). I'll trade it away if it will make things run better. Thanks.