Rookie

Figured out the issues why it was running rich. I put the new tune in and it was better. Not good by any means. Only had to hold throttle open 1/8 throttle to get it to run vs 1/4. Still would not idle. When it did fire earlier I had all of the throttle ports open not plugged off. I removed the tape and plugs from the TB and rolled it over. Boom! Fired and idle decent. This got me thinking their was a problem with the IAC. I pulled the IAC and it was out as far as it could be blocking the port. (starving it for air) I started the engine with it out and the IAC retracted. I put my finger over the port and it extended. It was working backwards. The IAC extended so far that it blew the plunger off of the motor. I did some Google research and Holley did what Holley does. Holley uses a GM LSx IAC but pins it out to a Chrysler wire harness. Pin A and C need to be switched in the harness plug. I swapped the pins around, blocked all the ports and installed the IAC. It fires right up and purrs like my old Holley carbureted HI-6M setups that I just replaced.

The headers clear the coils pretty good and the wires run perfectly between the pipes. It's a busy looking setup.

Smitty!! We are close. Let me know when you're ready!
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ICDEDPPL

Nice catch!!
Engines and set up look awesome, coil/plug is going to be so nice.

Gimme Fuel

Yes I ran into that issue on my 548 with Holley EFI. Strange they wire it for Chrysler IAC's, especially on a BBC harness haha. Easy fix but frustrating to diagnose!

Rookie

I was quite fortunate that I spent less than an hour figuring it out. If I would have had everything properly together and tried to fire it and the poor running scenario happened, I would still be baffled and would never have looked at the IAC. By it lighting off the other day on it's own was a blessing. I had a good scenario to work from.

They even pin their LS harness to the Chrysler pinout. They should leave those 2 pins A & C floating and the end user configures it. But, I guess they can sell more $90 IAC motors.

ICDEDPPL

What main harness do you have ? Is it related to the LSx harnesses only ?
I never had a problem with Terminator throttle Bodies (plug and play) but now with the whipples I have a separate IACs so I`m wondering if it`s going to be an issue.

b18cls1

all the holley EFI stuff uses the Chrysler iac. So if you have the holley or Chrysler iac your fine if you have the gm factory iac you need to swap the 2 pins.

Rookie

558-504 (104 main harness) Like stated earlier if you keep with Holley or Chrysler IAC's you should be fine. I only used the LS IAC because that is what the throttle body said to use. It appears that the Chrysler IAC might also work on my TB. The holes look the same distance apart.

ICDEDPPL

My new IACS are GM, so it looks like switch B&D?

b18cls1

a and c

Rookie