Hello all you do not realize how helpful you have been to me.

I transplanted a 454 tbi w/ 747 ecm into an 89 k5 blazer. I also changed the cam intake and heads to 781 gm heads as well as headers 3" duals and a built 700r4. Changed fuel pump to a 255l and fp is 35. BPW 100 added all the 700 tcc stuff and eliminated air n egr from 454 bin. I have a zeitronix wb installed and everything seems good WOT 12.5 afr. Ve table maxed in the 90 kpa 3200 rpm cell. Blms good 125 to 128. AE melts rubber from the 37" tires!

Only concern I have is p/n afr 14 to 15. In gear it drops to 12 smells quite rich too. Commanded idle afr 13.5 to 14.5 this 454 bin is set up open loop idle. I can adjust ve table to get afr where ever but p/n is always 2 to 3 points >. And if I cut fuel to get drive afr @14 as commanded, the blms in those cells get 135 on up. does this matter. I thought of playin with steps to subtract p/n to drive. But thought id ask opinions first.

It kinda surges and bogs out when tryin to go when the engine is cold. But not a big deal at this point in my tuning experience. Probably ae vs temp to high.

Thank you all,
I never could have made it this far without this site.
Jared

 

When it is cold change the choke tables. (Coolant temp).

If you don't have enough choke it will surge (lean surge)
and fall on it's face when you step on the gas.

 

Thank you that makes sense.

My main issue is should I adjust ve table1 idle cells to get in gear idle afrs where it runs better and oh well about high blms in those cells? Or should I try adjusting something else, Like park to drive steps or the throttle stop or iac steps vs temp?

Does the idle max and min afrs affect in gear or in neutral? My guess would be in neutral park then when in gear the steps to subtract when going from park to drive makes an adjustment.

Thank you,
Jared

 

Choke is only on 1-4 secs depending on coolant temp. Crank A/F is only on during crank when cold.

You are runnin off OL A/F-coolant-RPM-MAP table. To make your reads equal what is in that table increase the BPC a bit. that whould lean out that OL table as well. Also it will drop VE<100 to the 90's at that area you are max.

I idle zero iac steps. my preference. idle set with throttle stop screw.

Being in gear you are runnin off OL table at lower MAP as under load. IAC just puts you in differing RPM and maybe MAP. SA can vary also in gear vs out. If you set commanded idle A/F same at all cells you idle at then could help. Same with SA tables.

 

Through all my research. I was under the assumption that once the 454 bin Im running went into idle mode it started to use the OL idle routine and the "max OL afr at Idle" and the "min OL afr at idle", as well as VE1 table. (The closed loop flag on winaldl is consistent with an OL idle all the time) So the OL A/F vs coolant is out of the picture. Mine is essentially 13 from 72 degree on up to hot.

The AFR at idle in park is basically as commanded but when I shift it into gear it drops to 12ish I found the table "IAC steps to subtract park to run" and that is the only item I've found that is concerned with a shift from park to gear.

But after looking through the tunerpro tables and re-reading IAC logic under 747 in the tuning guide. I've come up with some ideas. Im going to watch IAC steps closer while all this is going on. Then try to adjust the IAC steps to subtract park to run to get what I want. (Should have sprung for the emulator, second thought should have sprung for ebl.) Then possibly adjust IAC steps fuel addr (msec) in an attempt to get afr as commanded.

This may just be an inherent problem with running high fuel pressure as Ive read about other places.

Ive read about this throttle stop thing before that might help as well because from what I think I comprehend, it would help to more completely burn fuel which I would think would show up as a leaner o2 reading.

The reason my bpc is so low and fpr so high is so injectors wont go static. Right now there at 85% duty cycle at just over 5000 per winaldl logs and holding tranny down in 1st. What started my whole crusade was I bought a stage 2 chip and it just didnt run like I knew it could. Essentially the main change for a stage 2 chip vs stock is an increase in bpc from 134 to 140. Which basically went static at a high idle. I probably could step it up a little though because my tranny shifts around 4500.

Whats the draw back to a maxed out VE table? Just no room to move or some other reason?

Going to run it tomorrow we will see what happens!

Thank You,
Jared

 

Quote: Then possibly adjust IAC steps fuel addr (msec) in an attempt to get afr as commanded.

The fuel adder is just that. It adds fuel when the IAC pindle opens. Opening IAC causes enleanment so the adder compensates. I dont think it affects A/F other than may drive the Integrator down(pulling fuel) if it is adding too much fuel. I added IAC fuel a while back and it improved throttle response. I may have added a bit to much(double the value in EBL.bin) but it liked it. I think IAC function is to control idle, prevent stall, add RPM for AC or alternator voltage or cold engine rpm speed. Basic idle low RPM control.

Quote:So the OL A/F vs coolant is out of the picture. Mine is essentially 13 from 72 degree on up to hot.

13.0/1 may be reasonable. that table is what engine runs on once started until it goes CL. Your WB should show those values as engine heats up. If not I would suspect BPC needs to change.

Quote: "max OL afr at Idle" and the "min OL afr at idle", as well as VE1 table.
I honestly dont know what those constants do. Maybe keeps that range of values should A/F wander or throws a malf flag CE light.

Quote: The reason my bpc is so low and fpr so high is so injectors wont go static

BPC is low so that tells ECU the injs are large so I would think it would throw off the other non BLM based correections. Not sure. Fortunately I have sufficient fueling so my BPC is close to what it should be. I think GM injectors can be run up to 36 lbs or so with no issues.

Max VE means the fueling is limited in that map/rpm cell. A higher BLM will result.