more questions...

**PJG1173** · 05-16-2012

I'm going to look at that trans adx file when I get home tonight. I'm hoping I get my TB back by the weekend so I can do some datalogging. I'm sure these stupid little things are what is costing me a 1st place finish by literally .1 sec's...

**PJG1173** · 05-31-2012

so I figured out the TCC lockup. I had to set the lockup speed to 125MPH in kickdown mode. Its still jump shifting 1st > 3rd and I don't know why. I also installed a bigger TB 622cfm vs. the stock 480cfm now I can't get the minimum idle set as I can't close the blades any farther. is there such a thing as too big of a tb for idle?

**gregs78cam** · 06-02-2012

Where did you get the 622CFM TB? Do the blades fit the bores properly, or was it a shoddy bore job? I have TWICE the amount of bleed air from a factory TB and can still get a decent idle.

No vacuum leaks, right?

**EagleMark** · 06-02-2012

Originally Posted by PJG1173

so I figured out the TCC lockup. I had to set the lockup speed to 125MPH in kickdown mode. Its still jump shifting 1st > 3rd and I don't know why. I also installed a bigger TB 622cfm vs. the stock 480cfm now I can't get the minimum idle set as I can't close the blades any farther. is there such a thing as too big of a tb for idle?

Not sure about the tranny?

On the Min air idle you either have a vacuum leak or like what happened to me with my sons 16197427 $0E was the procedure for closing IAC, then disconnecting wire like done on earlier ECMs did not work and left the IAC open, I forget what I had to do to finally drive the IAC all the way closed but it did take some fiddling while watching down hole to IAC pintle while turning key on/off etc... to realize it was not completely closed. It did drive me nuts for about a half hour. Never did find correct procedure for doing this on the 16197427? I think I took the IAC out, had a finger hold IAC pintle so it drove all the way out but did not going flying, then screwed it back in, I could feel and see it finally all the way in and finish tightening. Then left IAC plug wires disconnected and got min air set!

As Robert would say OMGWTFANNOYING!

So we do need to find out correct procedure for driving IAC totally shut on these. Crossing A and B like on 7747 does not work. It drives it all the way in then backs out, so theres your air/vacuum leak why you can't close throttle blades any further...

**PJG1173** · 06-02-2012

the local performance shop bored it and CNC cut new blades. they put it on the flow bench and it went from 481 cfm at 20" of H2O to 622 cfm when done. noticed a big difference in mid rpm range. When I got back I noticed they messed with the IAC position so maybe you are right and it isn't fully seating. although when idling I can see the nose of the pintle poking through the hole. I'll mess with it more tonight when I get home from work.

**EagleMark** · 06-02-2012

Originally Posted by PJG1173

although when idling I can see the nose of the pintle poking through the hole.

Yeah I fell for that too, it still was not all the way in... once I did get it fully seated it was easy to get idle about 100 below CL desired Idle, then reconnect IAC plug, clear codes and we ended up right where I like to be around 20 IAC counts warmed up CL.

**RobertISaar** · 06-03-2012

...... MPFI IAC stuff is just so much easier to deal with.

anyways, if i had to guess.... i'd say mode 4 commands might be able to be used to drive the IAC to 0 steps...

**JeepsAndGuns** · 06-03-2012

When I did mine on my 7427 I converted to MPFI. I drove it around untill the engine was warm. I then took a spare TPS I had, and hooked it up and put a peice of tape over it to keep it from moving after I got it to the .5 volts. I then adjusted the idle screw untill I got the IAC counts down to a more reasonable count. (I had TP open and connected the whole time so I could watch the tps volts and iac counts) After that, shut it off, hook the original tps back up, see the reading, remove, slot the holes and adjust back to where its supposed to be. Had no problem since. On mine, I actually had to open the blade a bit, as I had crazy large iac counts (like over 100+ at idle)

**EagleMark** · 06-03-2012

Originally Posted by JeepsAndGuns

On mine, I actually had to open the blade a bit, as I had crazy large iac counts (like over 100+ at idle)

That's usually the way the wear from hitting the stop screw, so it closes...

**PJG1173** · 06-03-2012

well I'm taking this one back to the machine shop next week. looks like they have the throttle blades a little off so one side is hitting the bore before the other side closes. other than idle the butt dyno is happy it feels like it pulls harder in mid rpms and its now calling for more fuel WOT in the mid to upper rpm range and map is staying around 100kpa all the way to 6000.