had in B NB 02 for about 3 seasons now. seems to be reading leaner as months go on in CL.

last night i was seeing at cruise 65 mph 1800 rpms about 16-17/1 on WB in CL. same fuel tables show 13.3 to 14.1/1 with WB in OL.

my aldl reading show BLM at about low 120's to a few 128. i had tables at 126-130 using NB and win ALDL. when i went OL i purposefully. enrichened all VE 10%. yes i knbow that is a large step BUT it gave me above 13's while cruising. i was attempting to bring in more enrichment EARLY ON when AE was involked. my logs showed a nasty lean spike before the AETPS comes in and only then all is well. "stumble". i have all AETPS for 0-3-6-9 at about 244 usec and then added in 61 each % from there. AEMAP is about 61-122-183-244-305. above all seems to help but still not right. on brisk accell no issue with AE . with car in roll and steady slow accell that initial leanness can be made ridiculously bad. dam near kill car and WB shows 30/1 and will POP and then the AE shows up and tires chirp. if i give up and floor it well they break loose. i am thinking with that slow deliberate accell i am not getting a lot of AETPS? should i enrich the AEMAP NOW as i am seeing the MAP go to like 90 at 1200 rpms? that is when i prolong the accell with slow TPS movement? OR should i fatten up the VE(60-100 map/ 1200-1600 rpms) and run OL ?

running OL surely will hurt gas mileage and that sucks.

 

You might want to consider doing some hardware diagnostics. It sounds like you've added in a massive amount of AE but it's still not enough?

1) I'm not sure what "B NB 02" means. I haven't been on the boards lately, so hopefully this isn't some new fancy thing that someone has cooked up and I'm just ignorant of it. Assuming you just mean a simple NBO2, the things do go bad, and they are cheap. B=Bosch? If so, swap it out for a GM NBO2. Either way, it coudln't hurt especially if the thing is 3+ years old and its reading is varying over time.

2) you've added a ton of AE but it's not enough? Have you checked to make sure all your sensors are OK? For example, if the TPS had a dead/flat spot somewhere off idle, you could have a huge hole in the effective AE if the TPS isn't reporting valid throttle position to ECM, until it hits a certan point and boom you're into AE. in other words check to see if you are actually realizing the AE you're tuning in to the flat spot.

3) ditto for the MAP sensor - it needs a rigid, short run of vacuum tubing to the manifold - you don't want soft tubing and long runs, because it weakens the signal to the MAP, especially transients. Or maybe the MAP sensor is going bad? when you crack the throttle, do you see the MAP report a higher kPa instantly, or does it lag behind?

That's where I'd look - if the thing is falling "out" of tune with no other changes, then it's more likely a hardware problem and not a tune you need to keep chasing. I'm not an advocate of "change parts till the problem goes away" but it sounds like your situation is certainly ready for some hardware diagnostics at least.

Hope this helps.

 

Maybe drop the %TPS enable.
And when nothing works fuel wise, look at timing.

I dunno, surely's been doing OK, in OL around here.

Closed Loop, means the ecm is averaging 14.7. Unless you try it, there's no way to say running a steady state, 15.5 might not be better.

 

1. a NB 02. typo. will swap to GM and keep Bosch as spare

2. TPS reads nicely in WB log per .01 increment. TPS is new 9/2004.

3. MAP sensor is original from what i can see, 101,000 miles. tubing is new from TB to sensor 9/2005. change in TPS brings immediate change in winALDL MAP from what i can see. wont hurt to replace it. will order out today.

Grump's Q: Maybe drop the %TPS enable.

i assume refering to PE. have at 50%. will drop to 30% as a "crutch" to AE and try that.

seems when manifold heat soaked and i do a slow accelleration in 2nd of 5th at 1500 rpms (under load)i can see the map shoot to 70-80-90 for VE and the prolonged bog occurrs. i am thinking i have a lean VE there as well. IOW 800/1000/1200 rpms and 60-70-80-90-100 MAP all values are lean. dont think i am in those cells long enough to get BLM correction so it gives me the value in tables as is. and WB shows 30/1 then drops to 12/1 and car catches and goes.

 

if you lock down the blm and int to 128/128 and data log your WBO2, it is much easier to tune for the VE cells you don't spend much time in. all you need is 2-3 consecutive frames of data to get a decent idea of what is going on in a particular VE/RPM range and make a correction based on the WBO2 data.

I've tuned this way before and it can be very helpful.