The "help save my marriage" LSx swap!

[Goldhawg]

I had to add the spacer to use the dished flexplate; I bought the spacer and new bolts from one of the vendors. Otherwise the stock tranny/torque converter bolted right up. I used the stock a/c compressor and Lextec's kit.

[Blasphemy]

What was the vendor you bought the spacer/bolts from?

[Goldhawg]

Jegs; here is receipt:
Order Qty Ship Qty Part Number Description Unit Price Extended
Contents of Carton No.: 1
1 1 809-12563532 LS C/SHAFT-F/PLATE SPACER 43.99 43.99
1 1 555-601011 BOLTS-6, LS CRANK SPACER 31.99 31.99
SALES TAX 5.32 5.32

[Goldhawg]

Ok, I picked up the Tahoe from the tuner, but he is off on vacation and I can't talk to him till he gets back. He still had a problem getting the idle speed down; the throttle blade is completely down and the IAC closed, and yet high idle. When I dropped it off, it was around 1500 rpm. We don't have a vacuum leak (sprayed all over w/carb cleaner, no response, and I did a vacuum check before, and it pulled 21" steady, but I don't have a smoke machine). The only way he could get it down was to back a ton of timing out at idle (-15 deg); with that the idle is down 7-800, with vacuum steady @ 13.5" (I think due to the timing he took out). He said he had two codes that might be doing it, and was supposed to get me the numbers (but hasn't yet, and now he's on vacation for a week). One was the turbine shaft speed; which googling on swaps suggests that is just a code he needs to delete from the tune, unless someone knows differently. The other was a throttle position code, but I don't know the #; when I picked it up neither code was showing, nor pending. Given I have no code, not sure what to do, if anything on throttle position. He said when he was tuning it runs great most of the time, other than a little rough at idle cuz he took out a lot of timing, but when he tried to make power out of it, it went out of open loop @ WOT above about 3500 rpm and would back fuel out so that it was much closer to stoichiometric, and you can't make any power w/o the add'l fuel. So he thinks there is some mechanical problem w/the throttle or something that is preventing him from being able to tune it properly and is wanting me to try and troubleshoot while he is on vacation.

Add'l thoughts/??s. I am running the stock LQ9 TPS, and it fits the TBSS manifold fine. However, the connector on the IAC only works w/my original vortec IAC, so that's what I'm using. Externally they look the same, but could that be part of my problem? Do I need the later IAC? Tuner said my current IAC is fully closed, but there is obviously still some air getting in somewhere.

Appreciate any counsel as to how you would proceed on troubleshooting.

[Skylark]

I would take a bit of modeling clay and put it on the pintle of the IAC. I would then cycle the key on and off a few times and then check the IAC to see if indeed that IAC was seating in the bottom of the bore,

[Lextech]

You could also try some clay rolled up and put around the throttle blade to make sure it isn't the throttle body passing too much air. Just because it looks closed doesn't mean that it is. It doesn't take much of a gap on a larger than stock T/B to pass too much air.

Jeff

[Goldhawg]

Thx for suggestions. So to clarify, the IAC from the vortec motor should be fine, I don't need the one from the LQ9? Tonight on the drive home I did get a P0507 code for high idle.

Also I have a new problem. Going home I turned on the A/C and I have no A/C. I had done the 3 wire a/c switch swap in the original 0411 pcm swap over, but I don't think I ever tested it cuz it was winter. The compressor does not engage; checking my a/c system I have plenty of low side pressure. Does the PCM need to command this on? Lextech, by chance did you inspect the way I had the a/c wiring set up when you had the harness to verify I did that correctly?

[Lextech]

The IAC's should be the same---As far as I know. The 3 wire sensor is wired correctly. See if you tuner has the A/C type set properly.

Jeff

[Skylark]

Just for grins I looked at rockauto and an 02 6.0 and a 97 5.7 have different part numbers in both the ac delco and the delphi lines.

[Lextech]

Hhmmm. That is interesting. They sure look like the same part.

Jeff