BLM- Long term fuel trim?

[ony]

bad ecm ?

[rudder2fly]

bad ecm ?

I have replaced the ECM with a rebuilt Advanced Auto Part same PROM is still being used that was installed when the truck was new and this is the 3rd ECM I have tried solving other problems none of which were solved by changing ECM's. I also bought a complete ECM 1227747 with prom AMUR on Ebay it is the latest ECM try and no help here I only saw a faster idle and a fast shift from 3dr gear into over drive mode. The seller said this would work in my truck but as I researched this PROM and it is for a 1987 truck which probably doesn't make any difference? I now am now running the Advanced Auto ECM with the ASDU Prom. I will try a run with the alternator unhooked and post the log here. G.S.

[ony]

paulse with vs battery voltage, on a 288 ecm at 11.2 volts paulse with is 1.063, at 14.4 volts it is 0.984 that will change blms a lot. I don't know what it is on a 7747.

[rudder2fly]

I have two logs to post. Truck3 is the motor running with the alternator not charging and Truck4 is charging. Sometime back I changed the TPS from the original because of the non start issue. This sensor was OK. They are non adjustable and the new sensor NAPA 3-1947 may be way off in adjustment. Maybe I should go back to the old sensor? G.S.truck3.xdltruck4.xdl

[EagleMark]

What kind of cable do you have? The 10k switch is on so your running in ALDL mode, which increases timing, raises idle and who knows what else. Your knock counts are going crazy driving with all that extra spark.

Have to turn that switch off and do another log.

TPS% at .90 is way to high, have to loosen it and twist it to get voltage back down. GM says .54 is perfect, I say anything under .70 does not effect it.

Not sure why a lower voltage makes BLM better/lower? Actually less voltage would be less fuel from pump and should make it worse!

WOnder if being in ALDL mode, added spark and all the knock counts is causing a misfire and giving the O2 sensor false readings? Have you ever set timing on this to 0 with bypass dis-connected as well?

[rudder2fly]

What kind of cable do you have? The 10k switch is on so your running in ALDL mode, which increases timing, raises idle and who knows what else. Your knock counts are going crazy driving with all that extra spark.

Have to turn that switch off and do another log.

TPS% at .90 is way to high, have to loosen it and twist it to get voltage back down. GM says .54 is perfect, I say anything under .70 does not effect it.

Not sure why a lower voltage makes BLM better/lower? Actually less voltage would be less fuel from pump and should make it worse!

WOnder if being in ALDL mode, added spark and all the knock counts is causing a misfire and giving the O2 sensor false readings? Have you ever set timing on this to 0 with bypass dis-connected as well?

I have the Moates Extreme ALDL cable set at 10k. The TPS sensor is nonadjustable! Timing is set at 2 degrees BTDC with the computer not in the loop. The engine will surge with thoughts of running right then drop back like it is dropping cyclinders when charging. Not charging runs pretty good. G.S.

[EagleMark]

Don't run 10k and get another log with charging system!

You can file the holes in TPS for more room but should not need it unless you have been adjusting the minimum air screw. You can also bend the tang on TBI behind sensor as a second choice.