I just put a 94 lt1 into my 95 3.4. I changed the engine compartment harness to a 95 lt1. I have connector c105 that goes to nowhere. i took out the pink wire from c105 and put it into cavity k on the other connector. i also spliced the 4pin black connector on the passengers side interior and got a hot from the pink on the blue connector. i now have spark, fuel, and injectors. the car will run, but i have no serial data. i cannot pick anything up on my scan tool. there is still a tan wire coming into the c105 connector that goes to nowhere(that is a serial data wire i think). Where do i need to jump power to and from to get my serial data working? im lost at this point and have no other ideas on what to do.

 

Looks like you need to extend the tan wire from cavity E of C105 to cavity F of C220 inside the car.

 

Thanks for the info. The scan tool now works and im not getting any trouble signals.
BUT...
The engine will start and run but it will not idle. I may be causing this problem myself because i do not have the air box hooked up. Will this cause the car to not idle? I only have the MAF and air temp part of the intake on but nothing else, i didnt connect the air to the black vaccum pump on the engine.
Also, There is a 3 pin connector coming off of the lamp harness, it is in the area of the fuse box and brake connections. It has a black, red, and red with black striped wire. I have no idea where this goes.

 

As long as the MAF is on, I would think it should idle ok. Monitor live data with the scanner to see what is going on.

If that other connector is off the lamp harness, that would mean it is not part of the engine harness. Since your car was a V6, I don't know what that might be. I am not familiar with stuff that is on a V6.

 

The lamp harness is also for the lt1. I changed it when i did my swap to accomodate for the dual fans. This three pin connector coming off of the lamp harness is in the area of the fuse box and air pump. It has the three wires, red, red and black, and black. Is the connector that goes to the air pump these colors? If the air pump is not all connected everywhere could that be why it will not idle? It seemed to idle fine when i had the MAF and air temp sensors not connected and before i got the serial data hooked up.... ?confused?

 

Yeah, it could be the AIR pump.

 

turns out it was the air pump connection. Now the car wont idle well and is running very rich, seems like its in the left bank of the engine. nothing on the scan tool but occasionaly get a 0016 Low Res. pulse code. I was thinking maybe the IAC is bad? i had the throttle body all apart during the rebuild. Im getting a bad o2 reading on the left side. The left 02 sensor is getting a reading of only about 8 when the right is at around 450. I replaced the o2 sensor and still the same reading.

 

try putting it in speed density and open loop and see if itll run

 

it is reading 'open loop' even with everything plugged in.....

 

also, when i did the swap, there were only 2 wires coming out of my c105 connector(pink and tan) i did the necessary things to get that working. dont think this has anything to do with my idle/rich issue..

 

Hey can you explain what wires you had to take from C105 and splice. I did an engine swap as well 1995 3.4L 1995 LT1. I would like to know which wires I need to move around or extend.


Let me know

Thanks

John

 

DTC 16 is the PCM being unable to find the low resolution pulse pattern from the Opti. Check the harness connectors - one at the body of the Opti, the other on a bracket on the passenger side of the intake manifold - to make sure its a good connection, with no corrosion and no bent pins. That code has nothing to do with the IAC.

When its idling, what IAC "counts" is the PCM commanding? If the PCM keeps increasing the counts to 160 and its still not at the required idle speed, the IAC motor may not be working.

The O2 sensor that is stuck at 450mV has an open circuit. Either the sensor is faulty, or the wiring harness has a break in it, or there's a bent/broken harness connector.

When is the other O2 sensor reading 8mV? If the AIR pump is running, that's normal. If the AIR pump isn't running, or if its at 8mV all the time, the wiring may be shorted to ground. If the PCM sees 8mV, its going to pour in extra fuel, but it won't do that until the PCM goes into closed loop. IT can't go into closed loop when the one sensor is reading 450mV. That indicates to the PCM the sensor is not working, and it won't go into closed loop until both sensors are working. It also will not go into closed loop until the coolant temp sensor is reading greater than 120-140*F. What is your coolant temp sensor reading as it warms up? If it showing a lower than actual coolant temp, the PCM may be running the engine very rich, because its assuming it needs cold start enrichment.