Would anyone on here be willing to take a look at my diacom logged data from my 91Z? (730 SD $8d etc.) and see if they see anything that my newbie eyes don't?

I know I already have a few problems (BLM's are in the mid-upper 130's and never go below 128 at all). I think this one might be related to a partially clogged cat but not really sure until I replace the cats?

I'm also curious about how many O2 crosscounts I should be getting? It's averaging about 10 a second.

And Finally i'm curious about how often (if at all) the ECM should need to pull timing out? With moderate throttle application (25-50%) I am averaging about 3-4 degrees of retard. Basically, it either jumps to 3* retard or 6* retard, decays out, then goes right back to 3* or 6*. Gas is 91 octane, MAT = 160F, CTS=200F.

My pocket programmer is now ordered...so hopefully not going to be newbie for too much longer.

thanks!!!

 

What part of CA are you from? If you're in SoCal I'll hook up with you and check it all out.

 

Thanks, I'm in NoCal - Sacramento to be exact.

I got my pocket programmer and have been playing around so far. I thought I was doing a good job on the lower VE table because I was getting all the BLM's in the 125-131 range (instead of 130-140 with the stock calibration) but then I went to start it one day and drive it, and every time I gave it a little bit of gas it started hesitating and cutting out/misfiring in the engine. This was before it had warmed enough to get into closed loop. So I popped the GM prom back in and problem went away. I'll have to go back over my changes and figure out what the heck happened, if I got a VE cell way off or something. It was very odd.

Thanks for the offer though!

 

Keep everyone posted on what is going on with your car! INfO like this with the solutions are great info to have and helps everyone on the board learn somthing.

 

Well, Ok then!

I logged the scandata for the car over a much longer period of time (let it get fully warmed up) and the BLM's return to more normal when it's fully heated up. So, I'm thinking that it's not a good idea to log data until the car has been driven at least 20 minutes. I had burnt a few PROM's that were based on my earlier scans, and I started to experience drivability problems, so I went back to the stock PROM calibration and am redoing the VE tables from the fully warmed up scan runs.

One thing that is puzzling though, is that I have occassional runs down to 108 on the BLM. My average BLM over 5074 rows of data (I captured every other frame) is 127, though...

For example....here is a few rows of truncated data from my scan log. I have NO IDEA why it's so rich here.
RPM_____KPH____kPa__Throt%_injMS___int_____BLM
1925____56.4____48____12____2.3____110____117
1925____56.4____47____12____2.2____114____117
1900____58.0____46____12____2.3____117____117
1900____58.0____46____11____2.1____118____117
1900____59.6____45____11____2.1____118____115
1925____59.6____45____11____2.0____118____113
1925____61.2____45____11____2.1____119____113
1900____61.2____46____11____2.2____120____113
1825____61.2____47____11____2.2____123____113
1725____62.8____49____11____2.5____126____113
1775____64.4____49____11____2.3____124____113
1750____64.4____49____11____2.2____120____111
1725____66.0____48____10____2.1____118____111
1725____66.0____48____10____2.1____118____109
1700____66.0____47____10____2.0____118____109
1700____67.6____47____10____2.0____118____108
1700____67.6____47____10____2.0____118____108
1950____67.6____42____10____1.8____118____108
2025____69.2____39____10____1.7____118____108
2025____69.2____39____10____1.7____121____108
1800____69.2____42____10____1.9____122____108
1700____69.2____46____10____2.3____126____108
1725____69.2____46____10____2.1____127____108
1725____70.8____46____10____2.0____119____108
1725____69.2____45____10____2.0____119____108
1850____69.2____44____10____1.9____119____108
2050____69.2____39____10____1.7____117____108
2050____70.8____39____10____1.6____118____108
2050____70.8____39____10____1.7____120____108
2050____70.8____39____10____1.7____120____108
2050____70.8____39____10____1.7____120____108
2050____70.8____39____10____1.7____121____108
2075____72.5____39____10____1.7____122____108
2075____70.8____38____10____1.7____124____108
2075____72.5____38____10____1.7____124____108
2075____72.5____39____10____1.8____124____108


Yet at the same time, here is some more data for same RPM-MAP and the BLM's are "normal". both runs were done the same night with the engine fully heated etc.... Notice above that the injector pulse time is anywhere between 10% and 15% LESS than the scan below, yet the below scan has BLM's that show a tad lean, whereas the above shows gross rich.

RPM_____KPH____kPa__Throt%_injMS___int_____BLM
1900____64.4____45____10____2.6____130____130
2000____66.0____42____10____2.4____128____130
2000____66.0____42____10____2.4____126____130
2025____66.0____41____10____2.4____128____130
2000____66.0____42____10____2.4____130____130
2000____66.0____42____10____2.4____130____130
2000____66.0____40____10____2.3____129____130
2025____66.0____41____10____2.4____135____132
2025____67.6____41____10____2.4____130____132
1975____67.6____38_____8____2.1____127____132
1975____67.6____38_____8____2.1____126____132
1975____67.6____38_____8____2.1____126____132
1975____67.6____38_____8____2.1____125____132
1975____67.6____38_____8____2.1____124____132
1975____67.6____38_____8____2.2____125____132
1975____67.6____38_____8____2.1____126____132
1975____69.2____38_____8____2.1____127____132
1975____67.6____38_____8____2.1____125____132
1975____67.6____38_____8____2.1____125____132
1975____67.6____38_____8____2.1____124____132
1975____67.6____38_____8____2.2____125____132
2000____67.6____38_____8____2.1____124____132
1975____69.2____38_____8____2.1____125____132
1975____69.2____37_____8____2.1____124____132
2000____69.2____38_____8____2.1____124____132
2000____69.2____37_____8____2.1____124____132
2000____69.2____37_____8____2.1____124____132
2000____69.2____37_____8____2.0____124____132
2000____69.2____37_____8____2.0____124____132
2025____69.2____37_____8____2.0____125____132
2000____70.8____37_____8____2.1____125____132

thoughts?

 

91Z, in both of your runs, its good to know that they are of the same night and temp, both air and engine. But what I am seeing is that the first log shows you coming off the throttle after accelrating rapidly(not flogging it or anything) and the second log shows that you have been at a steady speed, which seems to have let the numbers stabilize. I would run the car at the same RPM/MAP(-3+3)/speed if at all possible for a minute or so and that should be enough to get you some rather valid/accurate data.


Brendan

 

Maybe its the charcoal canister purge. That would cause a rich condition. I think it would be best to disable the CCP while tuning to avoid chasing your tail.

 

I checked the CCP, for the "rich" run the CCP started at 60% slowly progressing to 80%. for the "slightly lean" run, the CCP was at 100% the entire time. For the rest of the data, the CCP doesn't seem to have much of an effect at all on BLM.

At the moment I can't disable CCP (i'm using winbin and my definition file doesn't have any settings for CCP) but I just ordered tunercat so hopefully I can do that soon.

Anything else I should disable for this kind of work?