Coolant temp sensor location.

[jeremy5780]

Installing a EFI kit on my 4.2 and I need to install a new coolant sensor I'm not sure where in the block it goes. I have searched and cant seem to find a picture showing the location. I need to install a coolant sensor other than the one on the top of the block next to the valve cover. Thanks.

 

[Lumpy Grits]

D/S, back corner of the head. It's like a 1/8" pipe fitting.
LG

 

[jeremy5780]

That's where I was thinking, it's called the coolant main drain. I just wanted to make sure that would ok. thanks

 

[Lumpy Grits]

"Main drain" not a clue about that term.
I may have well miss-read your question. The location I gave you was for the temp sender. Not the CTS.
Here's the location......
Coolant Temperature Switch

LG

 

[jeremy5780]

I do not have that type of intake manifold. I have the Offenhauser 6257DP. I believe I need to remove a plug in the block somewhere and install the new 3 wire coolant sensor that came with the fuel injection kit. I'm just not sure what plug o remove.

 

[powdertwoplanker]

Sorry I can't help you out on the install, but do you mine telling me what kit your using? Do you have a build post going? I looking into an efi kit an leaning towards the Holley Sniper, but always looking for cheaper, easier, butan better options. Thanks

Sent from my E6782 using Tapatalk

 

[jeremy5780]

I actually bought my kit off of eBay from a guy called performance fuel injection systems. The kit was $999 shipped and came with everything needed for the install even a new HEI distributor with the correct wiring. Everything is brand new and he encourages you to call or write him with any issues and he will walk you through the install. I'm about 3/4 way done with the install and it is straight forward, every wire and connector is labeled and color coded. If it was not for this damn coolant sensor location I would be done! I didn't document my install simply because there are so many build threads out there. Even though most seem to be the junkyard install.

 

[powdertwoplanker]

I have seen that kit, good to hear you like it and he has been very help full. Thanks

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[Lumpy Grits]

Are there any 'plugs' in the manifold you can access?
LG

 

[Torxhead]

There are two plugs on the left side of the block that might work, but by now they are probably heavily rusted and the heads will strip out. There is also a thermostat housing that has a female pipe hole from a 4.0 engine that I have seen guys use. A last ditch effort would be to tap into a heater hose. I take it that you are out of holes on the intake manifold?

 

[jeremy5780]

My intake does not have coolant running through it, otherwise I would use it. I do have two plugs on the driver side of the block one is towards the front and there is one in the rear. I think I'm going to try the one in the front, but I had to order a 5/16 male pipe thread socket to get it out. Its going to be a bitch with the header in the way.

 

[jeremy5780]

Ok the plugs are not coming out of the block. I want to put in the yj thermostat housing with the coolant sensor insert but my motor currently has a pulley and bracket that goes to the A/C compressor and it is going to be in the way of the new thermostat housing. Any ideas???? I'm at my wits end with this coolant sensor.

 

[Lumpy Grits]

That smaller hose to the right side of the t'stat housing goes to the intake manifold. You do have a water cooled intake manifold after all.........
LG

 

[jeremy5780]

No that's not an actual picture of my engine. I couldn't get one to load my small hose goes to the heater core. I mainly wanted to show the pulley and bracket.

 

[Lumpy Grits]

Been nice if you had said that with the posted picture.
LG

 

[Torxhead]

Jeremy, looking at that pic, I would think this thermostat housing would work:https://www.napaonline.com/en/p/BK_6051754. It is for a '91 YJ w/4.0. As the threaded hole for the sensor comes out through the top.

 

[yellow85cj]

Not the least expensive solution, but it would work.
https://www.summitracing.com/parts/...meo9cb1TqrFW6e_fzayFpfEqxSPJZHR5BkaAuUl8P8HAQ

BTW, does the A/C work?

 

[Lumpy Grits]

That kit is for 1 1/2" dia hose. Don't think it will fit out CJ hoses.

LG

 

[yellow85cj]

That kit is for 1 1/2" dia hose. Don't think it will fit out CJ hoses.

LG

"AutoMeter offers these radiator hose adapters as another option for mounting your gauge's coolant temperature sender. These aluminum adapters are available in various sizes to suit your needs."

 

[Lumpy Grits]

Looks like, I overlooked that detail-
LG