Efi Coolant Temp Sensor

Im going to be installing a gm tbi kit soon and the ecm needs its own coolant temp sensor. I was originally thinking of putting the ecm sensor in the stock temp gauge port but the sensor that came with the tbi kit has 3/8npt threads but my intake manifold only has one 1/4npt port. I do have a 1/2npt port at the rear of the intake for the heater hose thats been plugged. Is the location of that port good enough or should the sensor be closer to the thermostat? Is there a tbi compatible coolant sensor with 1/4npt threads?

 

I had the same problem, on my intake there was a bushing in that hole, I got it out. I think I bought a expensive tap to clean the threads up, they where rusty. Put Teflon tape around the sensor threads to make sure they sealed.

 

The rear port should be just fine.

 

The EFI just needs a location representative of the overall engine temperature. I also think that rear port will suffice. It will likely be reading a temp only slightly less than one would get at the front of the manifold.

 

Why not just use an adapter for the front port? Does it move the sensor too far out?

 

Sorry, i forgot to reply to this. The probe part if the sensor is to big to fit into an adapter for 1/4" npt. I watched a YouTube video of some one that had the same problem with their motor and a holley sniper. They used a tee fitting into the heater hose and it worked for them. I also called AFI and they said they dont know of a compatible 1/4npt sensor but that the heater hose port should work, so im going that route. I'll just make sure to leave enough wire in case i ever change to an offenhauser intake manifold in the future.

 

I'ld go th the rear before using a tee. The AFI system needs to see a stable temp at operating temperature before it goes into closed loop the T could be the difference between it working well or running rich and not idling down.

 

I agree with Jw60.
Since you aren't running heater hoses that constantly cycle the water, just go to the rear of the intake.
I am running mine off of a brass T that is inline with the heater hose. I do not have a heater hose shut off valve so I am able to get away with it.