low BLM

[donf]

OK, I'm going to set FP back to 28 and do a proper data log tomorrow morning and post it. Thank you for using your time to help.

No problem, the ve table in your current bin looks really close to stock and with the increase in pressure and the modified engine, its is not going to be happy in some areas. I noticed in your log there were a lot of rich areas but there were lean cells too at the top. Once you log a good test drive and do some hand editing, you will probably be in a better place and it will just get better with more work. Just curious do you have the Harris chip bin to post? I just like to look at different tunes even if they don't end up working well.

[dhworkin]

This is the Harris binJHENDRY Vortec L31 BJYL.bin. This bin made the a transmission down shift noise when coming to a stop.

[donf]

Thank you very much, for that! I was just curious. In his credit, he did a lot more than JET does, but left a lot of important areas stock. It looks like he just boosted up the timing tables and messed up the trans settings and called it good. All fuel tables and enrichment settings are stock on that bin.

[dhworkin]

Hey there, I’m back at it. I started having idle problems so I started looking at the IAC and noticed it would not extending out when A and B at the ALDL are jumped. So I installed a new IAC and it would not extend, removed it and pulled the spring back on the old one and screwed the end out far enough to get it to closed when it was reinstated, then I set the stop screw to idle at 525rpms. After I shut it down and reconnected the IAC I could see it moving back and forth. It is erratic and goes 675 to 525 rpms with a stumble and constant surge at low speed crushing and idle. I suspect the PCM. What would cause this? Everything is clean and all is testing normal. D55C27B7-10DC-4B6F-910E-DCC2F8E72B4C.jpg4B35AA24-FE05-402E-B497-3096A275B11B.jpgA5CEFE6B-5658-4B99-8390-3278317B139F.jpg

[typhoonss92]

I have a very similar setup as yours. I have 65pph injectors with 24psi fpr. I has a very rump, rump rump at idle in park only. It wound up being the VE table not being smoothed out after using the excel spreadsheet, I am using Daves wbo2 excel sheet not the blm one. but from what nuekam just told me is it uses the cells directly around the cell for that rpm/map and if it is closer to the map rpm above, next, below it it will start to use that cell's data. if the 2 are too far off then it will ramp up and down. Also if you have major timing differences between the cells it will dot a very similar thing. At least this is what my issue was.
http://www.gearhead-efi.com/Fuel-Inj...standing/page4
he explains in post #54. I also has a very slight surge at low throttle like .7v tps and that went away also once I fixed the VE table.
Not sure what you are running but I have 26deg at idle in the SA. Hopefully this might help.

[dhworkin]

I know that will help, but if the IAC won’t extend when a&b are jumped and I can’t set the idle screw, I don’t think I can get that right until this is good. Does it sound like the computer is bad?

[sturgillbd]

Jumping the A & B aldl pins will not extend the IAC pintle on the later PCM's . I just adjust the minimum air screw until it shows ~10 counts at hot idle. You may have to adjust the screw and the shut the vehicle off for 20 seconds or so a couple of times to get it right. The surge can be causedby timing or fuel mixture. I had to lower the proportional gains in the idle O2 settings to control the surge in my setup. When viewing the datastream, look at the O2 voltage when the surge is occurring in monitors. You will probably see the surge happening with the O2 going full rich, then really lean.

Hope this helps

Brian