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My account is old but I am new to the group. I have recently been gifted a rough shape 84 Sport Coupe V6 that I tried to purchase from the previous owner for many years. I am in the initial stages of getting it derivable after 18 years of sitting in a driveway. It is currently more project than car but I already have it running and honestly fairly well.
The issue I have is with the top of the intake manifold. There are what appear to be 3 sending units for coolant temperature(Picture attached). I have read the wiring schematic and know the barrel connector unit with the black and yellow wires is the coolant temp sender/sensor for the ECU. I can not find what the other thick gauge 2 wire sender is for or why there is a 3rd sender(that looks identical to the one with the 2 wires) that is not hooked to anything.
Any insight to what the 2 wire connection that is present goes to and what the sender that has nothing connected to it is for would be greatly appreciated. I will most likely be replacing the water pump driven fan with more compact electric fans so if I can figure out the 3rd sending unit, I may be able to use that spot in the manifold for the fan control sender.
I did search the forum and could not find a direct answer to my question so please be polite if I overlooked a posting where this was already mentioned.
Thanks for the reply W.E.G.
Unfortunately I have the repair guide these are from and have already checked them. I can't for the life of me understand why the car would have 4 coolant temp senders but that is what it looks like. The wiring schematics only show the yellow and black 2 wire for the ECU and the green single wire for the gauge. Both of those are installed and working. I guess I'll just remove the one that's not in use and install my new one for my electric fan setup. If anyone has more information I would appreciate it. Thanks again!
The pic you said was attached in your OP isn't showing up.
I'm having some difficulty believing that there would be THREE coolant temp sensors.
Without seeing the pic, I'm just guessing. But, are you sure the third sensor penetrates the cooling system? I think you said it was on the intake manifold. Might the third sensor be a MAP sensor, or perhaps something else?
I can't for the life of me understand why the car would have 4 coolant temp senders .......
Believe it or not , by the time the 1989 2.8 MPFI rolled around there were 5 temperature senders , four measuring coolant and one measuring air . They were ;
CTS for the ECM
CTS for the CSI (Cold start Injector)
CTS for the temp gauge (or temp "idiot" light)
CTS for the radiator fan
And lastly , the one not measuring coolant , and instead measuring the MPFI's incoming air temp for the ECM , the IAT sensor .
Sadly , although I know every nut , bolt , and wire in the 2.8 MPFI , I've literally never seen a carb equipped 2.8 engine so I have no hard facts for you as to what is what on your engine .
Last edited by OrangeBird; May 13, 2018 at 12:11 PM.
Oh , and , the OP's photos show up just fine in both post #1 as well as the one he just posted , so I don't believe the problem is on the OP's end as to the pictures not being viewable to WEG (like I said , since the OP posted his post #1 pic the day before yesterday , I have been able to see it) . I just didn't respond cause like I said earlier I have no info on the problem he has .
Last edited by OrangeBird; May 13, 2018 at 10:30 AM.
Probably a problem on my end, but I'm not having trouble viewing other images on the forum. So, I really don't know what is causing this thread to be quirky.
I wouldn't say it as a zing (or "diss" in modern day slang) but your almost 10 year old OS may have something to do with your image viewing problems . The OP's pictures in this thread , as well as yours , show up fine here and when I try to click on the links you say are his images the links come up as no good . My guess is that your computer is doing something it isn't supposed to with his images but I have no clue what that would be .
Can someone with a 2.8 carb v6 please take a picture of the area to the right of the thermostat houseing/water neck and post it. I have tried doing searches for photos on Google but none of them are close enough to make out what or how many senders are plugged into the intake manifold.
Believe it or not , by the time the 1989 2.8 MPFI rolled around there were 5 temperature senders , four measuring coolant and one measuring air . They were ;
I wouldn't say it as a zing (or "diss" in modern day slang) but your almost 10 year old OS may have something to do with your image viewing problems . The OP's pictures in this thread , as well as yours , show up fine here and when I try to click on the links you say are his images the links come up as no good . My guess is that your computer is doing something it isn't supposed to with his images but I have no clue what that would be . 
