92blue

iTrader: (1)

I've been considering starting with a fresh bin and tuning from scratch for a bit now, just to see where that leaves me compared to my previous tune. When I first put the engine together, I started with an ARFP bin.

I decided to tinker with s_aujp_v3 this time, although I have a manual tranny. When I started working on the VE tables, I noticed that the BLMs were not moving. I can get across BLM cells, it wasn't stuck on cell 4, but no matter where I was on the VE table, it would show 96. INT was moving around alot, as there was alot of VE work to do.

I considered the possibility of just being that rich all across the board, but thats not the case. Pulling out fuel lost power and caused no change in BLMs, adding fuel yielded noticeable improvements. I did not notice anything unusual from datalogs.

Anyone have any input on this? I did some searching but couldn't find any info other than vss/ccp issues causing a "stuck in BLM cell 4" condition, which isn't the case here.

Grim Reaper

It can be a combination of rich with some mechanical problem. If you have a relocated MAT but haven't made any changes to the MAT Delta Inverse Table, then the colder air reading will cause the computer to go overly rich. A high fuel pressure setting (if you have an AFPR).

I know when I first started to tune my car, it was pegged low in MANY cells and I started to increase the Injector Constant (which does a global leaning) just to see if the BLMs came up (and it did).

I then set the Injector constant back to it's proper setting and started carving fuel out of the VE tables.

Also, there is nothing saying that you are rich in when you are in closed loop but "lean" in WOT. In other words, you may need to cut back fuel out of the VE tables but need to add for P/E.

92blue

iTrader: (1)

Thanks for your input. I'm considering the possibility of a mechanical problem, but can't think of anything to pay close attention to. MAT is in the stock location under the plenum. Timing is dead on. I do have an AFPR on the car, but its at stock 43 psi with the key on, engine off. I have a fuel press gauge in the car, and I have not noticed anything unusual with fuel pressure. I'm running a heated ACDelco O2 sensor, which is swinging under and over stoich pretty well, and crosscounts are high.

This BLM problem was not present with the old bin I was using. It started with s_aujp_v3. It occured to me that maybe there was a change in the ALDL datastream format, and a different .ads file is needed for s_aujp. Although that might explain whats happening, 1) I don't see a need to modify the datastream considering the intention of s_aujp 2) I didn't see any mention of such a change in the original super aujp post.

I haven't started tuning high kpa areas, the problem I'm describing has been at every BLM cell I've reached, but I was working on idle, cruise, light/mod accel, gradually working my way up the rpm range.

One thing I should have mentioned before.... the car seems to be begging for fuel everywhere, even at idle. I'm quite surprised at how much fuel its wanting at low rpm, low kpa areas. Idle quality improved dramatically after raising idle fuel some 4 or 5 %. I've added ALOT of fuel in some areas, and the car still continues to improve significantly. It was literally starving for fuel during decel with the stock s_aujp VE tables. I've added around 10-15% fuel under decel in the 2000-2800 RPM area.

Grim Reaper

I don't think the ALDL stream has changed as a number of people are using it with a scan tool and none have mentioned this. You are aware the S-AUJP also has extended the VE tables by relocating it, and thus your bin editor must must use a different definition than the stock $8D definition.

With TunerCat most guys go in with the TDF Editor and modify the start location and table length to account for the different Fuel Table.

JP86SS

iTrader: (1)

The only thing I can think of is that the cell boundary has been changed for the BLM.
Check your old RPM and MAP breakpoints against the S_AUJP and you can see if that is why you aren't moving as they did previously.

92blue

iTrader: (1)

Update...

Over the last few days, I've noticed the car has been terribly inconsistent, and getting worse by the day. Seems to want lots of fuel one day, seems to be overly rich 2 days later. I've also had a wandering "flat spot" in the powerband where I've watched the O2 drop to very low mV levels on ocassion, and the car hesitates. I add fuel and pull some timing, and the same thing happens, but at a different RPM. VE and spark tables were relatively smooth at these points, and nothing seemed to make any sense.

I started wondering if the Ostrich I'm running is being affected by interference or something along those lines.... and lowered the ECM /Ostrich onto the floor of the car. Before the Ostrich, I was using a moates memcal adapter with a ZIF socket and eeproms. When I picked up the Ostrich, I plugged it into the ZIF. I never thought that would be a problem, if it worked fine with the flash chips.

Guess what... tried plugging in the Ostrich directly onto the memcal adapter, and the car is very consistent now, and rich all across the board....
I don't understand why the ZIF socket was the problem, that seems to have been it. BLMs are moving now. Gonna start tuning from scratch again.
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Yes, I was aware of the extended VE tables, and was using the appropriate definition.

Thanks for the input guys...