Got my MAF issues resolved and installed a new O2 sensor. ECM goes into closed loop a lot faster, and stays there.
BLMs are 108 from idle to 2500. (haven't cruised over 2500 yet)
I went back to my stock ABWT bin and increased the inj size constant from 24 to 25, then to 26 and I'm still at 108 with the BLMs and 90-110 on the INTs at a 60-70 mph cruise. Running 43 lbs fuel press with the mods in the sig.

Should I continue increasing the constant or start dropping the fuel press, or???

 

nm

 

I now have the inj constant at 29lbs. Damn BLMs are still 108-112 during hiway cruise. INTs are 120-130. Why won't the BLMs come up??

 

What are the O2 readings now? Sounds like you may have a vacuum leak and it is dumping massive amounts of gas in to correct. You may also have some bad injectors. Also, have you tried unhooking the battery for a few minutes and hooking it back up? And what is your fuel pressure at?

When I started burning chips for my car a change of .5 in the constant yielded noticable changes in BLM's (like around 10 BLM's)

 

Run the MAF tables from the ARAP bin...those are the best starting point for MAF tables.

 

Try running with the 89 Vette chip. It is actually the same thing thing as ARAP but is not as extreme with the timing in the upper LV8. Should work real well for your application, all the fueling tables or MAF tables are the same. Also has some minor differences elswhere such as TCC control and few other misc things. Just plug both bins into your editor and compare all the fields.

 

In open loop, the O2 voltages are .8 and above.
In closed loop, the O2 readings fluctuate from .1 to .9 and don't seem to spend an unusual amount of time on either side of .5 volts. O2 sensor is brand new.

Just re-checked for vacuum leaks, none found.

I unhook the batt for at least 5 mins before each chip install.

Fuel press is at 43 psi.

I compared the MAF tables in the ARAP bin. They look pretty close to what I have, at least in table #1.

Not sure which bin is a 89 Vette bin.

My editor, GMECMEdit, won't allow comparing 2 bins that use 2 different ECU files. If I open 2 GMECMEdit programs, one crashes.

When car is started and warmed enough to enter closed loop, the INTs drop from 128 down to ~80. The BLMs start dropping shortly afterwards and don't stop dropping till they hit 108.

Just for grins, I un-hooked the power brake vacuum line and left it open. The idle speed increased, which I anticipated, but the BLMs and INTs went to 124, which seems wierd. The ECM seems to think I'm getting too much fuel.
I pulled plug #2 and found I'm definately not running rich. It was slightly tan on one side and white on the other. The plugs only have abt 50 miles on them.

Started thinking my bin was corrupt. Tried a different one that was supposed to be for a 87 L98 and got the same low BLMs at idle. Didn't drive car with that bin loaded.

Pulled the cold start inj but left it connected to the fuel rail. Power fuel pump to check for leakage, none found.

Checked the fuel press decay rate. Press dropped from 50 to 40 in abt 3 mins. Don't seem to have a massive leak anywhere.

ECM thinks I'm rich. Plugs say I'm not.
Not sure where to go from here.

 

Burned another prom with 25 lbs for the inj constant. Started eng. Let it warm up. ECM was in closed loop. BLMs were at 108 and INT abt 110. Started dropping fuel press from 43 psi. Finally, at 12 PSI fuel press, the BLMs and INTs were at 128. WTF??
I didn't think a TPI would even run at 12 PSI.. The injectors are supposed to be from LT1.

 

Just pulled and inspected all the plugs. I'm definately not running rich. They all looked the same. A little tan on one side and white on the other.

Burned the ARAP.bin and tried that, same result.

What else could cause the BLMs to be so low??

Anyone??

 

Wow the injectors can still operate at the low of a PSI. Are you setting you fuel pressure with vacuum hose disconnected, that’s the proper way of doing it. Thought that wouldn’t be the problem if when you change your injector constants it does nothing. Are you running long tube headers, if so try a heated O2.

 

I would normally set the fuel press with the hose disconnected, but the 12 psi was with the hose connected. Had the hose been disconnected, it probably would have been abt 16 psi or so.

Running stock L98 exhaust manifolds with the O2 sensor (brand new) in its' stock location.

 

You may have already mentioned it and it may not have anything to do with your problem, but how warm is your engine running? I know there are minimum temps to update BLMs.

Really though if your ECM is acting as if you're rich and the plugs are all white then it sounds like something is wrong in the communication between the O2 sensor and the computer. Have you tried reading the O2 voltage with a meter just to see if the number you're seeing on the scanner is accurate? (With a meter it will read lower due to the resistance of the meter. I haven't ever actually tried to do this, but I've read that it is possible)

Could it be a faulty ECM?

 

My coolant temp is at 200 degs. It should be warm enough.

I've measured O2 sensors with an O-scope where I used to work. That works well. Haven't tried a voltmeter.
If there was a bad connection, the voltage would be lower than actual at the ECM which would trigger the opposite problem (ECM would think it was too lean).

Starting to wonder now if an intermittent miss due to an ESC issue would cause an O2 sensor to read high.
I've gotten a couple of code 43s within the last week. Both times they cleared, but still makes me wonder.

 

I eventually got the BLMs close to 128 by increasing the inj constant up to 33 lbs. I'm not feeling real comfortable abt this large of a change, but then again, this is completely un-charted territory for me.
As long as the O2 sensor is cycling above and below .45 Volts I should be OK,, right??

Due to a temporary lack-of-funds, i'm running the stock L98 Y-pipe and cat connected to the stock (and original believe it or not) Crossfire mufflers which look very restrictive compared to even a stock L98 muffler.
Wondering how much effect that could be having on my BLMs.

 

Don't rely so much on your comp to tell you what you're running. Checking the plugs is a much more accurate sign of hw you're running. Computers aren't always acurate. IE my comp was indicating way lean so i added a small amount of fuel and it bogged the engine down to a super rich condition, but still read lean