Driveability issues

[Tinbender59]

Hello, I have a 1997 K1500 that I installed a 411 ECU into. everything is going OK, but my fuel millage is pitiful, 12-13 at best. I have been watching my timing, it has been running 28-31 degrees running highway speeds, knock sensor data is almost 0, and what else should I be looking at? I am trying to go about this trouble shooting methodologically, What is the first link in a closed loop system? (??should it be the O2 sensors??). The tail pipe is black (no converters), My first question is how do I figure out if the O2's are within the required range, and operating as advertised? What test can I run to check them?? or is there a way to test them? do we just spend the cash and hope that the new ones are "good". the way I see it the O2 is so important to the fuel delivery system, surely there is a method of proving their operation. But I haven't found anything yet? Which brings me to this, the Fuel injection brain trust, LOL!!

If I were smart enough I could develop a method to test them

[ScarabEpic22]

Do you have a wideband? Did you update the tune to include the proper injector data? Have you tuned it after the swap?

If you started with an Express van OS and VE table, it could be different than what your engine needs.

[Tinbender59]

Do you have a wideband? Did you update the tune to include the proper injector data? Have you tuned it after the swap?

If you started with an Express van OS and VE table, it could be different than what your engine needs.

yes on WB but not installed right now, I'll double check injector data, I did update it before I ran a couple of AUTO-VE tune's. but that is not guaranteeing that I've got it all done right??

[Tinbender59]

Another off the wall question, Can the custom OS work directly with a WB O2, as in if I switch say, to COS3, can I install a WB in the factory location and wire it into the factory wiring? will the system recognize this setup???

[ScarabEpic22]

yes on WB but not installed right now, I'll double check injector data, I did update it before I ran a couple of AUTO-VE tune's. but that is not guaranteeing that I've got it all done right??

Gotcha, been there before many times! AutoVE should help a bunch to dial it in, but you will need to keep refining it until your LTFTs are within your desired range (better then +/- 5 is a good place to start). You need to use your WBO2 as part of this process, the factory narrowbands won't give you relevant data once you get into PE mode. You'll see LTFT/STFTs go to 0 when in PE mode, so if you're only using NBO2 sensors, you'll never get any correction data to apply.

Another off the wall question, Can the custom OS work directly with a WB O2, as in if I switch say, to COS3, can I install a WB in the factory location and wire it into the factory wiring? will the system recognize this setup???

You theoretically *can*, however I've had nothing but issues trying to do this on my personal vehicle. I tried and fought it for 2-3mo, gave up and had a bung welded in. Have a new bung welded in, or replace the 2nd O2 sensor (post-cat). Know there will be additional latency with it installed farther downstream from the exhaust ports.

[joecar]

Post tune file and some log files (and your calc_pids.txt file).

[Tinbender59]

ok let me get everything set back up and a couple of logs, anything in particular that you want to see?

[joecar]

LTFTx
STFTx
HO2Sx1
EQIVRATIO
DYNAIR
MAF
MAP
ECT
IAT
TP
SPARKADV
KR
RPM

[Tinbender59]

will do, probably next week before I get back to you, it will be a little bit at a time on my end, no days off for 21 days, lol need the green!!

[Tinbender59]

joecar, would you recommend switching over to a COS? or wait until I get this figured out??