Holley HP EFI conversion
#191
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!
.




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!
.
Last edited by Rookie; 01-17-2021 at 09:16 PM.
#193
Registered
Joined: Oct 2010
Posts: 922
Likes: 128
From: Hemlock, MI
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!
.




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!
.
#194
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.
#195
Registered

Joined: Jun 2009
Posts: 9,969
Likes: 6,456
From: Chicago
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.

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.

#196
Registered
Joined: May 2007
Posts: 292
Likes: 60
From: Stuart, fl

#197
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.



