97 K3500 fresh engine runs great in open loop and horrible inj closed loop.

[Supercharged111]

Both are new and according to my scanner they are working fine. It does not stay in open loop when O2's are unplugged.

Can you expand on what you mean by "according to my scanner they are working fine"? And does it act up at all when the O2s are unplugged?

I was told by a number of tuners that you cannot datalog the computer in 7.4 powered trucks in 96 and 97. Because the truck is so old I cannot find any tuner that knows anything about them.

That's because hardly anybody is bothering to tune trucks so old. If they (or you) owned this:

14005 Jet Performance Dynamic Spectrum Tuner Programmer – Jet Performance Products

jetchip.com

It could be datalogged and tuned. Or you could 411 swap it and blow your tuning options wide open. PCM Hammer is free software and the hardware is way cheaper than the Jet. A 411 will aos give you more specific info than the black box's multiple random misfire. I'm not even sure P0301-P0308 can be datalogged on a blackbox and if so, would the data be any good? Those PIDs won't throw a code on the black box but they will on a 411.

 

[suspect racing]

Can you expand on what you mean by "according to my scanner they are working fine"? And does it act up at all when the O2s are unplugged?



That's because hardly anybody is bothering to tune trucks so old. If they (or you) owned this:

14005 Jet Performance Dynamic Spectrum Tuner Programmer – Jet Performance Products

jetchip.com

It could be datalogged and tuned. Or you could 411 swap it and blow your tuning options wide open. PCM Hammer is free software and the hardware is way cheaper than the Jet. A 411 will aos give you more specific info than the black box's multiple random misfire. I'm not even sure P0301-P0308 can be datalogged on a blackbox and if so, would the data be any good? Those PIDs won't throw a code on the black box but they will on a 411.

Thanks for the help. Ok now I am getting somewhere. What is a 411 swap? I will take a look at the PCM Hammer software and needed hardware. It looks like I will have to educate myself to make any headway. Two different folks who were recommended by others, to make changes to my black box said there was no way for me to create a data file and send it to them to have a look. They could only reprogram it with a best guess and send it back to me..