3 sensors on the EFI water neck

[nbristow01]

I have my water neck from the 318. The one that connects to the head and the upper rad hose goes to it. It has 3 sensors, I know the one is water temp but can someone tell me what the other 2 are? I am trying to determine if I will need them with the MS setup

[JohnS]

I don't know anything about MegaSquirt, but here's the parts descriptions

[MAD02]

One is the coolant temp sensor for the gauge in the car. The other is the cold start temp sensor. This system is like the Tii system that uses an extra fuel injector to add fuel to the engine when its cold. The third is the coolant temp sensor for the Bosch ECU.

When I did my EFI conversion, I removed all the sensors (except for the gauge sensor) and used a 3/8 inch NPT tap on the largest threaded hole to install a GM coolant temp sensor. Most DIY EFI systems are set-up for the GM sensor.

[Lebowski]

Hey Nbristow, I have an extra gm coolant sensor with the plug left over from my EFI conversion... If you want to go that way I'll send it to you for free if you pay postage.

Just spreading some good vibes to counteract the JhC negativity going around lately...

LMK

[bluedevils]

Hey Aaron, what's up bro?

[themoose]

You can use the standard Bosch sensors if you want, just use Easytherm to get the numbers you need. No need to go out and buy something you don't really need.

[Grover]

I used all three holes: One for the dash temp gauge, one for my electric fan (this can also be controlled via MS if you chose), and one for the MS unit. I used EasyTherm to recalibrate the standard Bosch sensor, and it was indeed quite simple. I'd guess you'll spend less time doing this than retrofitting something for the GM sensor. When you have a chance, drop me an email at trichardson AT clifbar DOT com and I can send you some more MS stuff you may find helpful.

[tdk930]

I think that 2 of the holes are 14 mm and one is 12 mm.  Does anyone know what size the dash sensor is?