Hey noobie tuning question?? I have just starting tuning with a burn1 and have yet to beable to get a laptop for dataloging. I checked what it was doing at idle with the scanner at work and its in open loop?? It also seems to be rich but I can assume that is my fault. Is there a reason that it would stay in open loop do to me tuning something wrong?? I have adjusted my bpc/base timing/ ve table's a fair amount/ as well as tps pumpshot. Its a 7747 ecm with AYUB bin in a 350 with cam and headers/intake etc. I also have an afpr. I know that i need a datalog to get things goin better but that will have to wait. Any help is appreciated!!

My guess is you have a cold thermostat and never reach the programmed CL temp enable, bad Coolant temp sensor, or your using a single wire O2 sensor with headers. It will cool off at idle and go back to OL.

THanks for the reply!! I am not using a cold stat, its a 195 or whatever a stock replacemant would be. I am using a single wire o2 at this point but I dont think that is the problem, but maybe?? I do have headers but im sure that it didnt do this on the stock prom. Thanks for the heads up though

OL idle is not a bad thing? you say rich? how rich are you?

i idle OL to smoothen out idle. idle synch too. in tables i am at 14.0/1 fully warmed and exhaust is clean. i have no idea what the A/F really is as cam is a bit on large size so WB says 15.5-15.9/1. I was told that reading is bogus due to overlap? but again idle is smooth and clean. if i up idle rpm to 1000 the A/F drops to 14.1 on WB.

Ok thanks for that reply, I will beable to datalog by the end of the week and then I will see what happens when driveing. I dont have much of a cam and my wideban is in the mail so it will be a while before i can check that. I just need to make sure that it goes closed loop when im driving right???

i would think it would flip CL unless you have it set up not to. mine flipped out of CL at 70 mph cruising occassionally until i got a heated 02.

Ok so I have checked my coolant temp sensor and it is working properly!! I went for a drive with the scanner at work and it doesnt matter what temp or throttle position im in it stays in open loop??? I'm sure that I didnt change the bin to force open loop and Im not sure what parameters need to be changed to do so?? All i have done is change the bpc/idle settings/turn off the egr with the temp method and change my VE table a little. Anyone have any other ideas that can help out a new tuner??? Any more info would be greatly appreciated!! Thanks

Where did you get that BIN?? lol, you are not going to believe this. . . It is a leaded fuel calibration that is typically for export. The enable closed loop CTS value is probably max'd out. When for export to a country that uses leaded fuels GM disables closed loop and cuts the wire to the O2 sensor.

RBob.

OK LOL I got that from my dealer in B.C Canada!! I guess that would answer my questions. Thanks i guess i got some tuning to do!!

wow, haha thats the last kinda thing im sure most people would think of.

RBob, is that something you just knew, or are you looking up the bin's name somewhere? if so, where? Thanks.