Tuning question

[discostu]

Driving an '89 Cavy 5 speed with a '94 3.1L swapped in. Running modified BFUZ code.

Upon startup in open loop, my BLM is always 120. When it switches to closed loop it goes normal, but in open loop it's always 120. Why?
The only thing I can find that I think might regard this is the "SAM Cell A (Idle)" 0x6ED and 0x6EE which are 120 and 135 respectively.

To me, this seems like it has something to do with the BLM (it's under the BLM settings at least) but I still don't get why it always starts at 120.

[Superdave]

BLM's don't matter till it's in closed loop anyways.. i'd just ignore it.

[discostu]

Yes, but the BLM stays at 120 into closed loop, it doesn't reset to 128.
Then my INT goes lean of course, to around 136-140, because the fuel is being cut.

Just doesn't make sense to me.

[Superdave]

post up your bin.. i agree, if it's going into closed loop at 120 then there is a problem..

have you reset the ECM ?

[torq455]

properly tuned, BLM/INT will read 128/128 in closed loop. when i connected my ALDL cable, i found my BLM was reading 136 and INT 128 in open loop. now, with a better tune and an open loop fueling revision, they are both now consistently at 128. i also recommend setting the sample rate to 4 per second. otherwise you'll stress on all the detail and try to fine tune before the rough tune. since i've done that, things are going rather well and quickly! bout time!

[Superdave]

properly tuned, BLM/INT will read 128/128 in closed loop. when i connected my ALDL cable, i found my BLM was reading 136 and INT 128 in open loop. now, with a better tune and an open loop fueling revision, they are both now consistently at 128. i also recommend setting the sample rate to 4 per second. otherwise you'll stress on all the detail and try to fine tune before the rough tune. since i've done that, things are going rather well and quickly! bout time!

even a completely stock factory fresh 3.1 won't read 128 all the time.. It'll always be different depending on how high you are above sea level, the humidity, air temp etc..


that's what the block learn and integrator are for.. correcting for atmospheric conditions.

[torq455]

which is why i said properly tuned.

[discostu]

Here's a copy of my bin.

[discostu]

New question.
I just picked up a heated O2 sensor. What temp are you guys allowing closed loop operation with a heated O2? Stock is 40 degrees C, but I'd like to lower that (maybe to 0* C??) for faster closed loop in the winter. I'm up in Edmonton, Alberta where it's pretty much a solid -30* C for a month and I'd like to see some better mpgs this winter. I'm also going to lower my closed loop entry timers after I do some cold testing to see how long it takes the O2 to start swinging properly when it's cold.
Last winter I saw a 5 city mpg drop (19 to 14) in the winter.

[torq455]

why not just lower the timers?

[discostu]

My trip to work is only about 5 miles. In -30*C that is not even enough distance to heat the car to operating temperature, even with a couple minutes of idle time.
I do not like to have my car idling for 10 minutes just to heat it up, but I also hate seeing 8 or 9 AFRs for most of my trip to work.

I've already decreased the wait timers a little bit (like 30 seconds or so), but I'd like to get into closed loop as fast as possible.

[Superdave]

for a 4 wire sensor i set them to 30 sec on cold and warm.. then 10 sec on hot.

i suppose you could lean out the "Open loop AFR vs Coolant Temp vs MAP" table and also the "Closed Throttle open loop AFR vs Coolant Temp" tables to try and save a bit of fuel when it's cold out... Stock tuning has those commanding 10.x and 11.x AFR's.

[Guest]

for a 4 wire sensor i set them to 30 sec on cold and warm.. then 10 sec on hot.

i suppose you could lean out the "Open loop AFR vs Coolant Temp vs MAP" table and also the "Closed Throttle open loop AFR vs Coolant Temp" tables to try and save a bit of fuel when it's cold out... Stock tuning has those commanding 10.x and 11.x AFR's.

For serious?

That's very rich!

My car goes that rich now, at start (even warm start), and want to reduce it, because it's just too much.

Mine is due to larger than stock injectors and haven't tuned any cold start parameters. I just can't imagine comanding such a fat AFR.

[discostu]

For serious?

That's very rich!

My car goes that rich now, at start (even warm start), and want to reduce it, because it's just too much.

Yup, stock startup AFRs along with the AFR timeouts that lower it further cause massively rich AFRs in cold and even warm startups.

[Superdave]

Yup, stock startup AFRs along with the AFR timeouts that lower it further cause massively rich AFRs in cold and even warm startups.

exactly the reason i disabled open loop mode.. mine would run in the 6.x AFR range and die constantly untill closed loop would come in and it would run great.