My Dual TBI Camaro Project

[gregs78cam]

Ok, I have been working on this for a few months now, everything is together, the engine runs but has some issues that I am working through. A little bit about the setup: 2pc rear main, 385 i built about 8 years ago, 10.5:1, 6" rods, TFS 23* heads, jesel belt drive, roller cam with 4/7 swap. It spent most of it's life in front of a T-56 with 4.10 gears,(dynoed 340hp/370Tq, and rich) until I just got tired of always shifting. So I found a 4L80E and decided while I was at it I might as well do the EFI since it could all be done with the same PCM. Now I know I could have used a 454 TBI with 454 injectors, but they are usually either hard to find, or cost more than I was willing to spend. So one day I stumbled across a CL ad selling 6 TBIs off various vehicles. I went go to get them and it turned out to be 7 for $35. So after cleaning up two matching ones(for the linkages) my Dual TBI was born(and inexpensively too) I am using a '7427, with Rbob's 4-injector upgrade, APU1, and TPV5. I could have used Rbob's fantastic EBL, but again the cost issue.

1. It was running way too rich at a "idle", I got this issue corrected by changing the injector size from 55 in the original .bin to 120, due to using 4 injectors

2. "Idle", I use this term loosly right now (1300-2200rpm). I am pretty sure it is an IAC issue, this morning when I put the ecm in diagnostic mode(jump A/B on ALDL), the pintle on the IAC remained retracted. ??? When key off the pintle extended. I have read on another site that some oldsmobile IACs were wired opposite. IDK if that is true but tends to make sense with way the engine idled(temps went up, idle went up instead of down) So with it extended, I unplugged the IAC and will try again tonight when I get off work. EDIT: problem found and fixed in Post#9.

3. Datastream communication. I am having a difficult time getting useful data consistantly from the AutoProm to the PC. Friday, before work, I hooked up the PC, loaded TP, and got everthing connected, car started, idled high but I had good data coming out. I let it run for a couple of minutes and shut it off. At the next key on all data was wrong, or flashing stupid numbers, like 345 degrees spark advance????. Any who, my next step will be to just burn a chip with Cyl. count, injector flow, and displacement changed from the original .bin, put the chip in, and start it with the IAC disconnected. EDIT: Found that you need to do it in this order: Open bin., Change MASK ID to AA, upload to Emulator, Then Emulate.

Where I go after that depends on what happens.