I am looking at an 89 6V 3.9L that I am restoring. I have the hose diagram courtesy of some help from Crazy4x4. I have reviewed what I could find with regards to tweaks and TSBs but I am left with some unanswered questions that I am trying to understand if there would be a reason for. I am trying to do a stock restore within reason (unless it makes sense not to follow

1. I have no Diverter Valve after the Air pump, so the connection to the throttle is capped off. Does it make sense I should not have a diverter valve? Some tweak I am missing? The air pump is direct to the upstream.

2. I am also capped off from the Heated Air Temp sensor.

With these capped off, I am not sure that I will have the right response with regards to potential backfire or reduction of air when the engine reaches appropriate temps. I am chasing this down hard because I am getting a knock when the engines warm underload that I think is fuel/air mixture (ie, vacuum).

Thoughts.

 

Air pump is made to delude the exhaust gasses by mixing in fresh air with the exhaust. This is there way back then for controlling emissions. I'm not to familiar with the older systems. But I didn't know of a diverter valve so if you know that those 2 are Sposato connect buy some hose at most auto parts stores and connect them.

As for the Heated Air Temp Sensor That sounds like something that does need to be there, for the correct fuel air ratios. You would want to replace it. If it is on the air filter cover it is okay. It is okay if missing.

 

Thanks Crazy4x4RT. I ordered the diverter valve and I am going to stick it back in the mix where it belongs after the air switch. I am even going to stick the throttle to heat sensors back on... I figure Dodge had a reason for it in the original design.