I'm on my 5th chip burn trying to tweak the TCC and AE to no avail. Changes to the tables do little to nothing for either area and I'm second guessing my changes are even correct or in the right direction at all.

I have a fresh 350 motor I put in to an '85 Chevy Blazer, TPI from an '86 Camaro, 1277165 ecm, and I've been using an ARAP bin as my base. Motor is modified with aluminum heads, big cam (lost the cam card and part number long ago but it's got a good lope to it at idle). Blazer has a 700r4 and I'm using speed input to the ECM but I don't have the park / neutral switch sorted so the ecm thinks I'm in park the entire time. Motor runs pretty good and according to the blm values the MAF tables and injector size are good. Recorded values vary between 124-128. No spark detonation recorded on the runs I've done. I have a air fuel ratio gauge connected in parallel to the O2 sensor so I can see how the fuel delivery is. I know it's not a wide band and a wide band is way gooder, but at least I can see what the ECM sees from the O2 for input.

Ok let's talk AE first. Whenever I ease in to the throttle or stab it from 0% to say 20% the engine stumbles before picking itself up and accelerating. When I watch the afr gauge when this happens it goes full lean. In fact while cruising at around 45 mph-ish and I ease in to the throttle the gauge will show full lean to the point where none of the led's light up on the gauge at all. From what I've read, the tables for AE vs TPS for MAP seem to be more direct control over a MAF system. I'm looking for some guidance on what to tune first to try and correct this.

Scalars. I made a couple changes to the delta value to try and get the AE to activate sooner with less load change and less TPS change:
Min Delta %TPS for Accel. Enrich: 1.95, (3.91 stock)
Min Delta LV8 For Accel. Enrich: 12 (56 stock)

Tables:
Acceleration Enrichment Factor vs. Change in LV8: 26.95, 23.05, 20.70, 20.31, 20.31 (Stock: 12.50, 12.50, 15.63, 20.31, 20.31) I changed these values trying to get more AE at lower load values and expected this to have the largest impact. I noticed maybe a subtle change in increasing these values but nothing substantial.
All other AE related tables are stock: AE Decay Factor vs Coolant, No. of AE Async Pulses vs Coolant, AE %BPW Factor vs Coolant Temp, LV8 AE Coolant Factor vs Coolant Temp.

What would you recommend I start with to adjust the lean AE condition and then fine tune?

TCC Lockup: The Blazer is obviously heavy in comparison to a light weight nimble vette, has 3.08 gears, and 33 inch tires. The ARAP TCC tables in general seem kinda silly, but other proms like AUJL or AUJN seem more practical but edits to them don't appear to have an effect on the lockup behavior. The Blazer originally had a carbed 305 with vacuum actuated TCC and it wouldn't go in to lockup until high gear around 45. With the the TPI system? It's always in lockup. I also suspect the 700r4 is a reman since it's trying to get to high gear as fast as possible and won't hold a gear to save its life. Pass 5 mph mid-throttle? Shift to second. Lock-up. Pass 20 mph? Shift to 3rd and lockup. My motor is built to make decent power above 2,000 rpm and it's lugging along at 1,100 trying to accelerate 5,000 lbs! Ok enough drama.

If I can't get the ECM to stay out of lockup until 45-55-ish and unlock under light throttle (>20% or so) then I'll probably put a bypass switch in to keep it from locking up until high gear. I've adjusted the scalar values and also the tables to try and achieve what I want but in reality my adjustments don't appear to be doing anything. I read a thread from 2004 that the unlock vs lock table headings might be reversed so swap the tps values which I did with no effect. Here are the latest values I've modified:

Scalars
TCC Coast Release: 45 (stock 32)
TCC Lock Delay After 4-3 Downshift: 1 (stock 0)
TCC Delay Before Lock in High Gear: 1.5 (stock 0.2)
TCC Unlock Prevention Threshold: 88 (stock 76)
Low Speed Limit for Low Gear Lock to Unlock Transition: 45 (stock 27) I understand this to mean when speed drops below 45, unlock when in low gear
Low Speed Limit for Low Gear Unlock to Lock Transition: 55 (stock 28) I understand this to mean when speed increases above 55, lock when in low gear
Low Speed Limit for High Gear Lock to Unlock Transition: 45 (stock 27) I understand this to mean when speed drops below 45, unlock when in low gear
Low Speed Limit for High Gear Unlock to Lock Transition: 55 (stock 28) I understand this to mean when speed increases above 55, lock when in low gear
All other scalars at stock values

Tables:
TCC Unlock Speed vs. %TPS Not in 4th: 0.39, 0.39, 0.39, 0.39, 0.39, 0.39, 8.98, 16.41, 23.83, 20.86, 37.11, 39.84
TCC Lock Speed vs %TPS Not in 4th: 0.78, 0.78, 0.78, 0.78, 0.78, 16.02, 23.83, 30.86, 35.94, 41.02, 46.09, 48.05
The values from the Not in 4th tables were copied to the In 4th tables for the same desired behavior.

I've attached my bin file if it's easier to look at the values directly. I appreciate any input, feedback, or guidance on this as it's quite frustrating especially on the TCC front to be making the changes I have without the desired outcome.

-Howdy

 

As for the lack of AE, it may be due to a fuel delivery issue. An non-baffled gas tank wreaks havoc on it.

The TCC may be wired in the trans to not use the ECM input. Unplug either the connector at the transmission or the switch on the brake pedal. Then see if the TCC still locks up. If so then the internal (under the pan) wiring needs to be changed.

{edit: this is bad info as the TCC solenoid still requires +12 volts from the connector to lock up. See further post}.

Could also set the TCC lock enable temperature high, for testing.

RBob.

 

I've installed a new baffled tank and high pressure internal pump. Tank is also full. I will keep increasing the AE values at low loads and see what happens if I'm on track adjusting the right tables.

If I touch the brake then the TCC will unlock. As a last resort I thought of running the brake input to a switch so the ECM thinks the brakes are always on until I'm ready for lock up in high gear at highway speed. Kind of a pita but it would get me by. I read that ARAP was coded to run with a TH350. Are there any logic or code differences between ARAP with a TH350 and ARAR with a 700r4?

Or I could put the original vacuum switch back on, that might be a better solution until I do a tranny rebuild.

-Howdy

 

There wasn’t a tpi with th350, arap and arar both were used with 700r4.

 

Ok, to change/add to my post, set the TCC lock up CTS enable to a high value. Leave the brake/trans connectors connected.

LC2A7 FCB 120 ; LOWER TEMP LIMIT, (50 C)

Setting that high will eliminate the ECM from locking the TCC. If it still locks, it isn't the ECM doing it.

RBob.

 

Adjusted the 'TCC Minimum Coolant Temp for Lockup' to the max allowable value (304°F) and it still locks up all the same. Tapping the brake will disengage lockup.

I'm making slow progress regarding AE. Add enrichment to this table, remove decay from that table. It's noticeable in the throttle response and AFR gauge, I just gotta keep tweaking in the same direction.

 

Tuning AE is kind of an art form...

I'm running a Miniram and it took years for me to figure out what worked and what didn't...

Seems like the AE delta TPS was the most important in terms getting the quick shot of fuel in there during throttle movements. The AE delta MAP (or in your case, vs the LV8) seemed to be less important, and in fact becomes a hinderance if overdone.

I started with the 4th gen LT1 AE tables since my Manifold was so similar. However, running the factory tables resulted in AFR's dropping to between 10 and 11:1 during large throttle movements and the throttle would feel very laggy. So I found that leaning out the delta-MAP AE helped a lot in terms of getting a crisp and response throttle. Watching the wide band, I reduced the AE delta MAP until I got little to no change in the prevailing actual AFR during a throttle transition. For example, if I'm at 13.5:1 and I move the throttle a little, it'll stay at about 13.5:1. The result is just a razor sharp, crisp, linear throttle during normal driving.

I also adjusted AE delta-MAP such that if I stab the throttle, the AFR goes to to the PE AFR and stays there during the PE event. For example, I'm cruising at 14.5:1, I suddnely go WOT (where my AFR is normally at 12.5:1 at the WB), I don't want the AFR dropping to 11:1 during the AE event and then shooting back up to 12.5. That's how you get a lazy response. Right now, it'll drop to between 12:1 and 12.5:1 and hold until I'm out of PE.

I also have the AE delta MAP decaying away much sooner. Factory LT1 decays out at 46% per injector firing. I increased that to 65% per injector firing. Basically GM was just overall way to fat on the AE delta MAP fueling on the LT1s. I basically just kept leaning out the AE delta-MAP tables and the throttle kept getting more and more crisp and responsive. Ultimately I got to where it was too lean and then backed off, so it's pretty much optimized now.

Delta TPS was a different story. The AE delta TPS is pretty much the factory tables for a 94, six speed Camaro (the AE delta-TPS tables for the automatic were way too rich). But it's significantly richer than the 8D TPI tables. Like you, I also reduced delta TPS threshold for entry into the delta TPS table (which was really needed off-idle tip-in on a Miniram).

Moral of the story is I think what works is a very quick shot of AE that terminates very quickly, and just enough delta-MAP AE to transition into the steady state fueling (either non-PE or PE, depending on the driving condition).

One thing to also check is your maximum async pulse width scalars. The maximum is 5.55 msec in stock ARAP. If you hit that ceiling, the ECM won't add anymore fuel no matter how much you program in with other tables and scalars. On mine, AUJP Max Delta-TPS pulse width is also set at 5.55 msec, so I set it to 15 msec (factory LT1) to make sure the ECM doesn't artificially limit my AE fueling.

 

Odds are that the trans is wired to lockup without ECM control. This is common. Will need to drop the trans pan and check/re-do the wiring.

RBob.

 

Thank you for the comprehensive write up on AE ULTM8Z!

RBob - Do you have any guidance on what I need to change in the wiring for ECM control?

If I'm going to drop the pan to re-wire I might as well put a shift kit in as well. I'm thinking the transgo SK700 kit.

-Howdy

 

Hard to say, they are several ways to wire the TCC lockup without the ECM. But, using the '89 $6E code, a 4th gear switch to the ECM is helpful. This allows the use of two sets of lock up tables. Just need to wire the switch so that it goes to the ECM. Note that the 4th gear switch can be NO or NC, which, IIRC, by '89, if flag set-able in the BIN.

Then the TCC ground signal from the ECM to control the lockup.

Some setups also include an over temperature switch in the trans to force lockup. Need to take care of it if present.

Be careful about installing a shift kit. If any changes or a kit has already been installed they can conflict.

RBob.

 

For the TCC wiring, here is a good way to go. Note that the 4th gear switch can be NO or NC. There is an option flag in the calibration to define which switch is in use.

Terminal A is power from the brake pedal switch.
Terminal B goes to ECM pin C8, high gear input.
Terminal D goes to ECM pin A7, TCC control.

Note the diode in parallel with the TCC solenoid coil, so don't reverse the voltage on it.




RBob.